OCULUS Pentacam Interpretation Manual
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OCULUS Pentacam Interpretation Manual

High-resolution rotating scheimpflug camera system for anterior segment analysis
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Pentacam
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Pentacam
HR
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InterpretatIon GuIde
3rd edition

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Summary of Contents for OCULUS Pentacam

  • Page 1 OCULUS Pentacam ® Pentacam ® InterpretatIon GuIde 3rd edition...
  • Page 2 Foreword We thank you for the trust you have put in us by purchasing this OCULUS instrument. In doing so you have chosen a modern, sophisticated product which was manufactured and tested according to strict quality standards. Our company has been doing business for over 120 years. Today OCULUS is a medium-...

  • Page 3: Table Of Contents

    Table of contents 1 Introduction..............................5 2 Description of the unit and general remarks..................5 3 Differences between the various topography maps of Pentacam®..........6-11 3.1 Calculation of corneal power..........................6 3.2 Sagittal power map (also called axial power map)...................7 3.3 Refractive power map............................8 3.4 True Net Power..............................9...
  • Page 4 14.2 Position and depth of INTACS® rings....................106 14.3 DSAEK with specks at the interface....................107 15 Using Pentacam® technology to evaluate corneal scars, planning and documenting surgery outcomes by Arun C. Gulani, MD, MS..............108-116 15.1 Case 1: Corneal scar with RK incisions and cataract...............112...
  • Page 5 18.4 Step 3: Evaluation of corneal spherical aberration ..............140 18.5 Step 4: Evaluation of corneal cylinder ..................140 19 Dependency of effective phacoemulsification time on Pentacam® Nucleus Staging (PNS) by Mehdi Shajari, MD, Wolfgang Mayer, MD, Prof. Thomas Kohnen......141-142 19.1 Introduction ............................141 19.2 Case 1: Low PNS and low EPT ......................142...
  • Page 6 Table of contents 23 Case reports from daily practice.....................161-172 23.1 Case 1: Cortical cataract by Tobias H. Neuhann, MD..............161 23.2 Case 2: Remove sutures after corneal transplant surgery? by Tobias H. Neuhann, MD........................ 162 23.3 Case 3: Keratoconus and cataract by Tobias H. Neuhann, MD..........163 23.4 Case 4: Corneal infiltrate by Prof.

  • Page 7: Introduction

    Pentacam®. We may not have covered everything which might be of interest, and we therefore ask anyone using the Pentacam® for their help in improving this guide step by step. Please forward us any cases or observations of particular interest, and we will be happy to incorporate them in this guide.

  • Page 8: Differences Between The Various Topography Maps Of Pentacam

    1.3375, see below). Due to SA, however, the refractive power in the periphery is actually higher. The Pentacam® refractive maps, as they are called, are calculated on the basis of “Snell’s law” of refraction using precision ray tracing, thereby taking this effect into account.

  • Page 9: Sagittal Power Map (Also Called Axial Power Map)

    The Pentacam® is able to measure the anterior as well as the posterior surface of the cornea. This allows further corrections to be made. The Pentacam® provides a number of different maps for predicting corneal power.

  • Page 10: Refractive Power Map

    Differences between the various topography maps of Pentacam ® Refractive power map This map (Figure 3) uses only values from the anterior surface, but it also takes effect “A” (see above) into account. It calculates corneal power according to Snell’s law of refraction assuming a refractive index of 1.3375 to convert curvature into refractive power...

  • Page 11: True Net Power

    Differences between the various topography maps of Pentacam ® True Net Power This map (Figure 4) shows the optical power of the cornea based on two different refractive indices, one for the anterior (corneal tissue: 1.376) and one for the posterior surface (aqueous humour: 1.336), as well as the sagittal curvature of each.

  • Page 12: Equivalent Keratometer Readings Power Map

    Differences between the various topography maps of Pentacam ® Equivalent Keratometer Readings power map This map (Figure 5) was designed to take into account the refractive effects of both the anterior and the posterior surface. Another requirement was that it should output power values which in normal cases (no Lasik) would be comparable with simulated K (SimK) values, which are usually derived from sagittal curvature map.

  • Page 13: Total Cornea Refractive Power Map

    Differences between the various topography maps of Pentacam ® Total Cornea Refractive Power map This map (Figure 7) uses ray tracing to calculate the refractive power of the cornea. It takes into account how parallel light beams are refracted according to the relevant refractive indices (1.376 and 1.336), the exact location of refraction and the slope of the surfaces.

  • Page 14: Recommended Settings And Color Maps, Displays And Values

    Recommended settings and color maps, displays and values Physicians who are starting to work with the Pentacam® often turn to us with questions on settings such as step width on the color scale, or which maps and values to consider before doing LASIK, PRK, RK or phakic IOL (pIOL) implantation or in keratoconus examinations etc.

  • Page 15: Recommended Color Maps, Displays And Values

    „ „ (available in the Pentacam® HR only). Calculate the required pIOL power using the implanted calculator. Use the database to find a pIOL that best matches the patient’s subjective refraction. Its fit in the anterior chamber is simulated in 3D and the minimum clearances are displayed. The aging simulation allows a simulation of the pIOL position in up to 30 years.

  • Page 16: Glaucoma Screening

    Evaluations of the corneal astigmatism (An article was published in „The Highlights of Ophthalmology“ Assessment of Corneal Optical Quality for Premium IOLs with Pentacam®“ Highlights of Ophthalmology • Vol. 39, Nº 4, 2011) Zernike Analysis to determine the amount HOA and LOA „...

  • Page 17: Differences Between Placido And Elevation-Derived Curvature Maps By Prof. Michael W. Belin

    Figure 8: Placido based topography of OD and OS allowing no conclusion regarding keratoconus The right eye seems to be fine. The left eye is a little steeper. The Pentacam® 4 Maps Selectable answers clearly the question.
  • Page 18 Differences between Placido and elevation-derived curvature maps The right eye (Figure 9) has a regular corneal thickness, but the elevation maps of the anterior and posterior surface indicates this cornea as a suspicious cornea. Both sides show an inferior position of the cone with suspicious elevations.
  • Page 19 Differences between Placido and elevation-derived curvature maps The left eye (Figure 10) indicates an inferior steepening, but a smooth anterior elevation map. The reason for the thinning in the pachymetry map is the posterior elevation map, where there are significant elevations of more than 30 μm. Note that the position of the thinning in the pachymetry map and the highest spot on the elevation map are exactly at the same position.

  • Page 20: Form Fruste Keratoconus

    11): Figure 11: Placido based topography of OD and OS Pentacam® anterior segment analysis revealed normal pachymetry (normal distribution & central thickness > 650 μm). The anterior and posterior elevation revealed a slightly decentered apex. This had led to a “false positive”...
  • Page 21 Differences between Placido and elevation-derived curvature maps Figure 12: 4 Maps Selectable showing a form fruste keratoconus false-positive topography in OS Figure 13: 4 Maps Selectable showing a form fruste keratoconus false-positive topography in OD...

  • Page 22: One's Findings By Ina Conrad-Hengerer, Md

    Ectasia Display one finds unmistakable evidence of an advanced keratoconus of both eyes (Figure 16, Figure 17). Here the Pentacam® reveals a disease that the patient could have been made aware of many years earlier. The patient was informed about this corneal pathology and its prognosis. To improve his visual acuity he had a rigid contact lens fitted for his left eye.
  • Page 23 The Fast Screening Report Figure 14: Fast Screening Report showing abnormal pachymetry and elevation data with unambiguous signs of keratoconus in OD Figure 15: Fast Screening Report showing abnormal pachymetry and elevation data with unambiguous signs of keratoconus in OS...
  • Page 24 The Fast Screening Report Figure 16: Belin/Ambrósio Enhanced Ectasia Display (version III) showing keratokonus in OD Figure 17: Belin/Ambrósio Enhanced Ectasia Display (version III) showing keratokonus in OS...

  • Page 25: Case 2: Fuchs' Dystrophy With Dmek Cataract Surgery - Progress Evaluation

    The Fast Screening Report Case 2: Fuchs’ dystrophy with DMEK cataract surgery – progress evaluation A 63-year-old female patient with bilateral cataract and Fuchs’ dystrophy underwent combined cataract and DMEK surgery. This section reports on her progress, documenting the condition of her right eye prior to surgery with the Fast Screening Report (Figure 19) and the Corneal Optical...
  • Page 26 The Fast Screening Report Figure 19: Fast Screening Report showing the presurgical condition in a case of Fuchs’ dystrophy Figure 20: Fast Screening Report at one month after DMEK surgery...
  • Page 27 The Fast Screening Report Figure 21: Corneal Optical Densitometry showing the presurgical condition in a case of Fuchs’ dystrophy Figure 22: Corneal Optical Densitometry at one month after DMEK surgery...

  • Page 28: Case 3: Corneal Injury Sustained From An Eye Drop Bottle After Cataract Surgery

    Analysis based on the Pentacam® Fast Screening Report revealed an abnormal value for K Max (anterior surface) as well as anterior and posterior elevation (Figure 23).
  • Page 29 The Fast Screening Report Figure 24: 4 Maps Refractive with suspicious curvature and elevation maps of the anterior surface Figure 25: Compare 2 Exams showing changes in anterior surface elevation within a period of one week...

  • Page 30: Refractive Power Distribution Display By Ina Conrad-Hengerer, Md

    Slit lamp microscopy showed clear, refracting media bilaterally with no corneal scarring or other abnormalities. Fundoscopy was unremarkable. Mesopic pupil diameter was 3.00 – 3.50 mm. The above refraction values were found to be confirmed in the Pentacam® refraction map. The possibility of keratoconus was excluded (Figure 26, Figure 27).
  • Page 31 Corneal Power Distribution display Figure 26: 4 Maps Refractive showing with unremarkable elevation maps and curvature map in OD Figure 27: 4 Maps Refractive showing unremarkable elevation maps and curvature map in OS...
  • Page 32 Corneal Power Distribution display Figure 28: Corneal Power Distribution showing normal power distribution in OD Figure 29: Corneal Power Distribution showing a markedly increased power from 2.0 to 3.0 mm in OS...

  • Page 33: Corneal Ectasia

    „ sph -5.00 cyl -2.25 A 39° VA 20/30 „ „ The Pentacam® 4 Maps Refractive map (revealed corneal ectasia in both eyes, with a more advanced condition in OS (Figure 31). In OD (Figure 30) the central cornea showed less distortion, permitting relatively good uncorrected vision.
  • Page 34 Corneal ectasia Figure 31: 4 Maps Refractive of OS showing post-LASIK ectasia Figure 32 : Pachymetry progression in OD Figure : 33 Pachymetry progression in OS The pachymetric progression is abrupt in both eyes, providing a significant indication of ectasia (Figure 32, Figure 33).

  • Page 35: Case 2: Ectasia After Lasik? By Prof. Michael W. Belin

    Corneal ectasia Case 2: Ectasia after LASIK? by Prof. Michael W. Belin A 46-year-old female had undergone LASIK 2 years prior. She was interested in further vision enhancement for her dominant right eye. Her best spectacle corrected visual acuity (BSCVA) was 20/20+ with sph -1.25 D.
  • Page 36 Orbscan®. This device routinely fails to correctly identify the posterior corneal surface in postoperative patients, leading to underestimates of residual bed thickness and frequent incorrect diagnosis of post-LASIK ectasia. Here the Orbscan® incorrectly reads the corneal thickness 37 μm thinner than the Pentacam®, incorrectly suggesting ectasia (Figure 36).

  • Page 37: Corneal Ectasia

    Corneal ectasia Figure 36: Orbscan ® 4 maps incorrectly suggesting ectasia in OD Figure 37, Pentacam ® 4 Maps Selectable revealing there to be no post-LASIK ectasia In this example Orbscan® measured the pachymetry 37 microns (μm) thinner than Pentacam®.

  • Page 38: Glaucoma

    We measured 24 mmHg with a Goldmann tonometer. Figure 38: 4 Maps Refractive revealing a thick cornea Examination with the Pentacam® 4 Maps Refractive display (Figure 38) yielded a corneal thickness of 728 μm, resulting in a corrected IOP of 11 mmHg according to the Dresdner scale. Further examination on the Heidelberg-Retina-Tomograph (HRT) revealed a healthy optic nerve, and we therefore advised the patient to stop his medication.

  • Page 39: Case 2: Yag Laser Iridectomy By Eduardo Viteri, Md

    0.6 in both eyes. The lens was clear, and gonioscopy examination revealed a narrow angle in both eyes (grade I-II). The anterior segment exam with the Pentacam® (Figure 41) documented an ACA of 22.5 degrees with an ACD (epithelial) of 2.43 mm.
  • Page 40 Glaucoma After YAG laser iridectomy had been performed several of her anterior segment measurements changed (Figure 42). This is quite evident in the differential display (Figure 43). Figure 42: General Overview display 10 days after YAG laser iridectomy in OS showing improved ACA and ACD values Figure 43: Compare 2 Exams showing changes from before to 10 days after YAG laser iridectomy in OS...

  • Page 41: Screening For Narrow Angles By Dilraj S. Grewal, Md

    ACV from 64 to 92 mm³. Comments The Pentacam® is quite useful for measuring the ACA in narrow angle glaucoma, although this may be difficult in 360º because of eyelid interference. More consistent data can be obtained by measuring peripheral ACD and ACV.
  • Page 42 Glaucoma Figure 45: General Overview display showing a low ACV, shallow ACD and narrow angle in OD Figure 46: General Overview display showing a low ACV, shallow ACD and narrow angle in OS Humphrey visual fields were full in both eyes (Figure 47, Figure 48), and optical coherence tomography (OCT) and retinal nerve fiber layer (RNFL) scans showed retinal thickness to be normal...
  • Page 43 Glaucoma Figure 47: 24-2 Humphrey visual field: Figure 48: 24-2 Humphrey visual field: full visual field in OD full visual field in OS Figure 49: Spectral domain OCT showingnormal RNFL thickness in both eyes...

  • Page 44: Case 2

    Glaucoma She underwent a prophylactic laser peripheral iridectomy in both eyes, following which ACV increased from 64 to 94 μm, ACA widened from 19.7 to 26.4 degrees and ACD deepened from 1.83 to 2.08 mm. We previously demonstrated that a cutoff value of 113 mm3 for ACV discriminates narrow angles with 90% sensitivity and 88% specificity [3,4].
  • Page 45 Glaucoma Figure 51, General Overview display showing a low ACV, shallow ACD and narrow angle in OS...
  • Page 46 Glaucoma Humphrey visual fields revealed early defects in both eyes (Figure 52, Figure 53), while the OCT RNFL scan showed an abnormally thin RNFL corresponding to the visual field defects in both eyes (Figure 54). Figure 52: 24-2 Humphrey visual field Figure 53: 24-2 Humphrey visual field showing an early superior showing an early inferior...

  • Page 47: Evaluating The Anterior Segment In Phacomorphic Glaucoma By Dilraj S. Grewal, Md

    At that time she had undergone bilateral laser peripheral iridotomies, which were patent on examination. On slitlamp biomicroscopy she was found to have a very shallow anterior chamber but no irido-corneal touch. Pentacam® Scheimpflug imaging (Figure 55) confirmed the diagnosis of phacomorphic glaucoma as evidenced by a shallow ACD of 1.75 mm, an ACV of 65 mm...
  • Page 48 Glaucoma Figure 56: Scheimpflug Image showing increased ACV, deeper ACD and wider ACA following removal of the lens and posterior chamber IOL implantation...

  • Page 49: Screening For Refractive Surgery By Prof. Michael W. Belin

    10 Screening for refractive surgery Screening for refractive surgery by Prof. Michael W. Belin 10.1 Screening parameters, 4 Maps Refractive Display 10.1.1 Suggested installation settings The following are my guidelines for pre-operative refractive surgery screening for keratoconus: Use the 4 Maps Refractive Display showing anterior elevation, posterior elevation, pachymetry „...

  • Page 50: Proposed Screening Parameters

    10 Screening for refractive surgery 10.1.2 Proposed screening parameters It is essential to check the settings for the fitting zone of the BFS in the settings of the Pentacam®, since this influences the borderline numbers (Figure 57). Figure 57: BFS fitting zone If you are using the manual (fixed) 9 mm zone for fitting the BFS, the proposed screening „...

  • Page 51: Strategy On How To Go Through The Exams

    10 Screening for refractive surgery 10.1.3 Strategy on how to go through the exams The way I usually go through the exams is: Î Look at anterior elevation first Î Look at posterior elevation Î Look at the pachymetry and thickness distribution. Off-center distribution of corneal thickness is highly suspicious Î...
  • Page 52 10 Screening for refractive surgery This 4 Maps Selectable display (Figure 59) shows a normal with-the-rule astigmatic cornea (astig. 2.6 D). Both the anterior and posterior elevations demonstrate a similar pattern, as does the anterior sagittal curvature. The curvature maps reveal a steep cornea (K1 = 47.6, K2 = 50.2), but the elevation maps do not reveal any suspicious areas.
  • Page 53 10 Screening for refractive surgery This 4 Maps Selectable display (Figure 60) shows a normal with-the-rule astigmatic cornea (astig. 4.1 D). Both the anterior and posterior elevations have a similar pattern, as does the anterior sagittal curvature. The anterior elevation map is symmetric, and the curvature shows a symmetric astigmatic pattern.

  • Page 54: Astigmatism On The Posterior Cornea

    10 Screening for refractive surgery 10.3 Astigmatism on the posterior cornea This 4 Maps Selectable display (Figure 61) shows only a small amount of anterior (astig. 1.1 D) but a larger amount of posterior astigmatism (a more defined astigmatic pattern). However, because the posterior cornea contributes a much smaller amount to the overall refractive state of the eye, the posterior astigmatism reads only 0.4 D, in spite of a fairly well defined astigmatic pattern.

  • Page 55: Spherical Cornea

    10 Screening for refractive surgery 10.4 Spherical cornea This 4 Maps Selectable display (Figure 62) shows a normal, relatively spherical cornea (astig. 0.7 D). The anterior elevation shows no defined pattern, which is mirrored by the anterior sagittal curvature. The corneal thickness is slightly high (583 μm in the thinnest reading). DIAGNOSIS - normal spherical cornea Figure 62: 4 Maps Selectable showing a spherical cornea...

  • Page 56: Thin Spherical Cornea

    10 Screening for refractive surgery 10.5 Thin spherical cornea This 4 Maps Selectable display (Figure 63) shows a relatively spherical anterior cornea (both anterior elevation and anterior sagittal maps) and a more pronounced astigmatic pattern on the posterior corneal surface. Because the optical properties of the posterior cornea (no cornea/air interface) differ from those of the anterior surface, the refractive astigmatism of the posterior cornea is listed only as 0.3 D.

  • Page 57: Thin Cornea

    10 Screening for refractive surgery 10.6 Thin cornea This Show 2 Exams display (Figure 64) shows from OD and OS the posterior elevation and the pachymetry maps. The posterior elevation shows a normal astigmatic pattern, as does the anterior elevation (not shown). The pachymetry maps show the thinnest regions OD at 492 μm and OS at 483 μm.

  • Page 58: Borderline Case Of Keratoconus

    10 Screening for refractive surgery 10.7 Borderline case of keratoconus This 4 Maps Selectable display (Figure 65) shows a low-grade paracentral island (maximal elevation in island + 8 μm) in the anterior elevation map and a diffuse oval island on the posterior surface (maximal elevation in island + 16 μm).

  • Page 59: Displaced Apex

    10 Screening for refractive surgery 10.8 Displaced apex This is a 4 Maps Selectable display of a normal astigmatic eye with a thick cornea (644 μm) (Figure 66). The anterior elevation map shows a "displaced apex" (displaced inferiorly). This causes the curvature map (anterior tangential curvature) to show an asymmetric pattern.

  • Page 60: Pellucid Marginal Degeneration

    10 Screening for refractive surgery 10.9 Pellucid marginal degeneration These are pictures of classic pellucid marginal degeneration (PMD). The pachymetry map (Figure 69) shows the band of thinning located 1 - 2 mm from the inferior limbus. This is an area that cannot be imaged on a Placido system, which is limited to imaging the central 9.0 mm.

  • Page 61: Asymmetric Keratoconus

    10 Screening for refractive surgery 10.10 Asymmetric keratoconus This is a 4 Maps Selectable display (Figure 70) of a normal astigmatic eye (OD) with a thin cornea (thinnest reading 483 μm) and a noteworthy abnormality in the pachymetry distribution with a significant inferior-temporal displacement of the thinnest zone.
  • Page 62 10 Screening for refractive surgery The left eye shows a major posterior ectasia (+ 91 μm) on inferior island, and marked inferior displacement of the pachymetry map (thinnest reading 414 μm) (Figure 71). The anterior elevation shows a somewhat irregular astigmatic pattern but without any obvious positive island. The tangential curvature incorrectly locates the cone much more inferiorly than the cone location shown by both the posterior elevation data and the pachymetry map.

  • Page 63: Keratoconus With False Negative Findings On Curvature Map

    10 Screening for refractive surgery 10.11 Keratoconus with false negative findings on curvature map This 4 Maps Selecable display (Figure 72) shows a classic keratoconus in OS. The anterior elevation map shows a minor island that is still within the normal range. The posterior elevation, however, shows a very significant area of inferior ectasia (positive island up to + 35 μm), and the pachymetry map is significantly displaced and thinned to 499 μm.

  • Page 64: Keratoconus Greater In Od Than Os

    10 Screening for refractive surgery 10.12 Keratoconus greater in OD than OS Look at the Show 2 Exams display of posterior elevation and pachymetry of OD and OS in this patient with keratoconus (Figure 73). The right eye shows a significant posterior island (ectatic area) associated with marked corneal thinning (430 μm) and significant inferior-temporal displacement of the thinnest area towards the area of the abnormal posterior elevation.

  • Page 65: Classic Keratoconus

    10 Screening for refractive surgery 10.13 Classic keratoconus This 4 Maps Selectable display shows a case of classic keratoconus in OD (Figure 74). Both anterior and posterior elevations show a prominent island of positive deviation (maximal at +33 μm anterior and +89 μm posterior) with an accompanying displacement of the pachymetry map (thinnest reading 485 μm).

  • Page 66: Corneal Thickness Spatial Profile By Prof. Renato Ambrósio Jr

    "tomos", which means "slice", and "graphia", which means "describing". The aim of this section is to provide a comprehensive understanding of the current corneal thickness profile studies that have appeared since the introduction of the Pentacam® software, along with other approaches that could be developed in the future.
  • Page 67 11 Corneal Thickness Percentage of Increase in Thickness (PIT) PIT can then be calculated for each position using the simple formula: (mean corneal thickness in the ring – thinnest corneal thickness) PIT = Î thinnest corneal thickness Clinical results In a published study involving 46 eyes of 23 patients (13 females) diagnosed with mild to moderate keratoconus and 364 normal eyes from 196 patients (97 females), statistically significant differences were observed between the two groups (P <...
  • Page 68 In developing the Pentacam® software the results of our studies served as a basis for engineering new summaries and graphs that would help clinicians explore CTSP and PIT so as to be able to objectively evaluate thickness profiles and detect ectasia.

  • Page 69: Screening For Ectasia By Prof. Renato Ambrósio Jr, Marcela Q. Salomão, Md

    11 Corneal Thickness 11.1 Screening for ectasia by Prof. Renato Ambrósio Jr, Marcela Q. Salomão, MD The new software combines the elevation criteria of Michael Belin, MD for screening for ectasia. This opens up new horizons in analysing corneal thickness for diagnosis and classification of corneal ectasia.
  • Page 70 11 Corneal Thickness Figure 78: Show 2 Exams Pachymetric showing a normal thin cornea Figure 79: Show 2 Exams Topometric showing an ectatic cornea...
  • Page 71 11 Corneal Thickness Figure 80: Show 2 Exams Pachymetric showing an ectatic cornea Currently, most diagnostic and classification criteria for keratoconus are based on anterior corneal curvature data derived from corneal topography. We wish to emphasize that the thickness profile described here should be used in conjunction with the classic ones provided by corneal topography.
  • Page 72 11 Corneal Thickness To test the hypothesis that the CTSP and PIT increase sensitivity for the detection of very early forms of keratoconus we studied patients with keratoconus in one eye and in the other a cornea of normal surface curvature as evidenced by Placido topography. Interestingly, the contra-lateral eyes also exhibited signs of abnormality on the CTSP and PIT graphs (Figure 81, Figure 82).
  • Page 73 11 Corneal Thickness Compared with the specificity of artificial intelligence based indices for detecting ectasia, topometric indices are fraught with high false positive rates, especially in cases with moderate keratometric asymmetry and inferior steepening (Figure 83, Figure 84). Figure 83: Show 2 Exams Topometric giving a false positive diagnosis of ectasia Figure 84: Show 2 Exams Pachymetric showing a normal cornea...

  • Page 74: Case 1: Fuchs' Dystrophy By Prof. Renato Ambrósio Jr, Marcela Q. Salomão, Md

    11 Corneal Thickness 11.2 Case 1: Fuchs’ dystrophy by Prof. Renato Ambrósio Jr, Marcela Q. Salomão, MD Contrary to ectasia, in which central thinning causes a more pronounced or abrupt increase in the thickness values from the center towards the periphery, corneal swelling makes the cornea homogeneously thick, decreasing the increase in thickness values towards the periphery.
  • Page 75 11 Corneal Thickness Figure 86: Show 2 Exams Pachymetric showing a case of Fuchs’ dystrophy...

  • Page 76: Case 2: Ocular Hypertension By Prof. Renato Ambrósio Jr, Marcela Q. Salomão, Md

    11 Corneal Thickness 11.3 Case 2: Ocular hypertension by Prof. Renato Ambrósio Jr, Marcela Q. Salomão, MD The case below shows a patient with ocular hypertension. Please note the clear appearance of the corneas in the Scheimpflug images (Figure 87, Figure 88) below as well as their thickness in the Show 2 Exams display (Figure...
  • Page 77 11 Corneal Thickness It is shown (Figure 89) that moving peripherally from the 4 mm zone the thickness progression graph does not run parallel to the normative data. The progression index is 0.9 for OD and 1.1 for OS. When screening for ectasia we would consider 1.2 as the borderline.

  • Page 78: Case 3: Early Fuchs' Dystrophy With Glaucoma By Prof. Renato Ambrósio Jr, Marcela Q. Salomão, Md

    11 Corneal Thickness 11.4 Case 3: Early Fuchs’ dystrophy with glaucoma by Prof. Renato Ambrósio Jr, Marcela Q. Salomão, MD This 60-year-old patient was referred to us for a second opinion on his diagnosis of normal tension glaucoma, corneal disease and early cataract. The Scheimpflug images show higher scatter (less clarity) and a second peak at the level of Descemet’s membrane and the endothelium (Camel’s sign) in both eyes (Figure 91, Figure...
  • Page 79 11 Corneal Thickness Figure 93: Show 2 Exams Pachymetric showing an abnormal cornea in OD and OS The progression index was 0.5 in OD and 0.8 in OS, i.e. lower than normal in both eyes. Goldmann IOP (10 a.m.) was 18 mmHg in both eyes. The averages of two ocular response analyzer measurements of Goldmann-correlated IOP, corneal compensated IOP and hysteresis were 19.6, 24.1 and 5.2 mmHg in OD and 16.7, 23.5 and 6.1 mmHg in OS.
  • Page 80 11 Corneal Thickness Figure 94: Specular microscopy in OD and OS Completing the case report is the HRT examination displayed below. The optic nerve is damaged, and the rim configuration is abnormal both in the image and according to Moorefield’s classification. This patient has glaucoma as well.

  • Page 81: Screening Parameters By Prof. Renato Ambrósio Jr

    These parameters can be used as a guideline, but the clinician should also consider other clinical parameters of the Pentacam® and clinical diagnostics. Average pachymetry progression index 0.5 <...

  • Page 82: Belin/Ambrósio Enhanced Ectasia Display

    12 Belin/Ambrósio Enhanced Ectasia Display Belin/Ambrósio Enhanced Ectasia Display 12.1 Why elevation is displayed by Prof. Michael W. Belin Before we can talk about how we display elevation tomographic data, we should take a step back and understand why I am a proponent of elevation based tomography. To do that we need to have an understanding of how elevation and curvature differ.
  • Page 83 12 Belin/Ambrósio Enhanced Ectasia Display Figure 97: Keratometer The modern keratometers in use today are very similar to those used over a century ago and similar inherent limitations apply. The accuracy of the keratometer is conditional on the uniformity of the central corneal curvature over the area measured.
  • Page 84 12 Belin/Ambrósio Enhanced Ectasia Display Figure 98: Keratoscope Computerized videokeratoscopes provided a wealth of new information but still suffered from the same limitations of the century-old earlier techniques. Some of these limitations are related to the physical limits of reflective technology (permitting examination only of the anterior surface), and others are related to curvature measurements regardless of the technology used to produce them.
  • Page 85 12 Belin/Ambrósio Enhanced Ectasia Display The Pentacam® uses a technique of optical cross-sectioning to identify the anterior and posterior corneal surface, the anterior iris, and the anterior and posterior surface of the lens (Figure 100). By measuring these surfaces and their relative position elevation maps of the anterior and posterior cornea can be produced as well as a full corneal thickness map (additionally lens measurements, but these will not be discussed here).
  • Page 86 12 Belin/Ambrósio Enhanced Ectasia Display The problem with raw elevation data is that it lacks sufficient surface variation for the observer to easily separate normal eyes from abnormal. In order to make elevation qualitatively useful, we need to display the data in a more clinically relevant manner. To do this we typically display the elevation data against a non-planar reference surface.
  • Page 87 12 Belin/Ambrósio Enhanced Ectasia Display Figure 103: Elevation maps based on different diameters Since the goal of refractive screening is to allow the physician to easily separate normal from abnormal, it works out that a BFS set at the 8.0 mm optical zone is optimal. A BFS computed from the central 8.0 mm will mask (i.e.
  • Page 88 12 Belin/Ambrósio Enhanced Ectasia Display Keratoconus will show a positive island of elevation, as the conical protrusion is above the BFS. The location of the island and its magnitude will correspond to the location of the cone and the severity of the ectatic change.
  • Page 89 12 Belin/Ambrósio Enhanced Ectasia Display Figure 107: Elevation map of a keratoconic cornea using an enhanced reference shape with an exclusion zone to improve detectability The enhanced reference surface more closely resembles the more normal periphery (Figure 108) allows for easier identification of ectatic regions. Figure 108: Enhanced reference surface 109, the standard BFS is shown on the left, while the enhanced reference surface on the Figure...

  • Page 90: Simplifying Preoperative Keratoconus Screening By Prof. Michael W. Belin, Prof. Renato Ambrósio Jr, Andreas Steinmüller, Msc

    Belin/Ambrósio Enhanced Ectasia Display (BAD display) was designed to utilize the data supplied by a Pentacam® rotating Scheimpflug camera and provide a comprehensive keratoconus screening display. The display combines the anterior and posterior elevation and pachymetric data into one all-inclusive display giving the clinician a more complete overview of the corneal shape and allowing for quick and effective screening of refractive surgery patients.
  • Page 91 Enhanced Ectasia Display II – software # 1-17b37) simplifies the physicians’ evaluation and was updated in response to inquiries from Pentacam® users. The new display reports five differential parameters individually change in anterior elevation from standard to enhanced reference surface,...
  • Page 92 12 Belin/Ambrósio Enhanced Ectasia Display Figure 110: Belin/Ambrósio Enhanced Ectasia Display (version II) of a normal highly astigmatic eye Both anterior and posterior elevations are normal and show a typical astigmatic pattern. The central cornea has a normal thickness at the apex of 532 μm but shows little progression towards the periphery causing the PIT tracing to be relatively flat (opposite of what you would see in ectasia).
  • Page 93 12 Belin/Ambrósio Enhanced Ectasia Display Figure 111: Belin/Ambrósio Enhanced Ectasia Display (version II) of a cornea with an isolated suspicious area on the posterior cornea The anterior elevation shows a very low degree of astigmatism, and the pachymetric progression, thinnest value and TP displacement are all within normal limits. The posterior elevation change is further heightened by the enhanced reference surface, and the bottom display for the posterior elevation reveals a yellow zone.
  • Page 94 12 Belin/Ambrósio Enhanced Ectasia Display Figure 112: Interesting example of the value of the Belin/Ambrósio Enhanced Ectasia Display (version II) and the “D” values This cornea has a number of variables that fall in the suspicious area. Both the anterior and posterior elevations show small central yellow zones and the pachymetric progression and TP displacement are also in the yellow zone.
  • Page 95 12 Belin/Ambrósio Enhanced Ectasia Display Figure 113: Belin/Ambrósio Enhanced Ectasia Display (version II) of a case diagnosed as “mild” keratoconus based only on the anterior cornea. A fuller picture is obtained by tomography There are also changes on the posterior surface (both yellow), more dramatic changes in the pachymetric progression “Dp”, which is red at 3.70 SD from the mean, and a mild displacement of the TP (yellow).

  • Page 96: Interpretation Of The Belin/Ambrósio Enhanced Ectasia Display

    12 Belin/Ambrósio Enhanced Ectasia Display 12.3 Interpretation of the Belin/Ambrósio Enhanced Ectasia Display Standard elevation maps: The left half of the Belin/Ambrósio Enhanced Ectasia Display the elevation data is shown please refer Figure 113. The first two elevation maps (placed side by side) display the baseline relative elevation of the cornea of the best fit sph.
  • Page 97 12 Belin/Ambrósio Enhanced Ectasia Display Figure 114: Belin/Ambrósio Enhanced Ectasia Display (version I) showing elevation data on the left and pachymetry data on the right)

  • Page 98: Pachymetry Evaluation

    12 Belin/Ambrósio Enhanced Ectasia Display 12.4 Pachymetry evaluation The Pentacam® provides a detailed corneal thickness distribution map with 3 μm accuracy and repeatability. Display interpretation (pachymetry): The pachymetric portion of the display includes the pachymetry map (corneal thickness), the two graphs showing the current of this patient thickness progression versus a normal population and the pachymetric indices.
  • Page 99 12 Belin/Ambrósio Enhanced Ectasia Display Figure 115: Placido topopraphy in OD showing no keratoconus Figure 116: Placido topography in OS showing no keratoconus...
  • Page 100 Had it only been judged on the basis of Placido topography, CCT and the clinical parameters, the case would have qualified as a good candidate for LASIK. However, the Pentacam® exam revealed some telling characteristics of the cornea which in our view constituted a high risk case for ectasia.
  • Page 101 12 Belin/Ambrósio Enhanced Ectasia Display Figure 118: Belin/Ambrósio Enhanced Ectasia Display (version I) showing subclinical keratoconus in OD...

  • Page 102: Early Ectasia With Asymmetric Keratoconus By Prof. Renato Ambrósio Jr, Fernando Faria-Correia, Md, Allan Luz, Md

    12 Belin/Ambrósio Enhanced Ectasia Display 12.6 Early ectasia with asymmetric keratoconus by Prof. Renato Ambrósio Jr, Fernando Faria-Correia, MD, Allan Luz, MD A 20-year-old male patient with asymmetric keratoconus presented with BCVA 20/20 in OD and 20/15 in OS. The data in OS show a relatively normal topography pattern, while those in OD reveal mild keratoconus (Figure 119).
  • Page 103 12 Belin/Ambrósio Enhanced Ectasia Display The Belin/Ambrósio Enhanced Ectasia Display shows abnormal values for posterior elevation and thickness distribution. Figure 120: Belin/Ambrósio Enhanced Ectasia Display (version III) showing mild keratoconus in OD Figure 121: Belin/Ambrósio Enhanced Ectasia Display (version III) showing forme fruste keratoconus in OS...

  • Page 104: Locating The Cone By Prof. Michael W. Belin

    12 Belin/Ambrósio Enhanced Ectasia Display 13 Locating the cone Refractive surgery screening commonly involves Placido disk based corneal topography and central corneal thickness measurement by ultrasound [14,15,16]. At the time of its introduction the ectasia risk score system, which is based on a topographic classification, proved to be an improvement of the refractive surgery screening process [17,18].

  • Page 105: Jos J. Rozema, Msc, Phd

    LASIK or post PRK, or with infectious keratitis, corneal mucopolusaccharidosis and keratoconus. The scan protocol is simple and does not lengthen the Pentacam® scan time. We will here describe some of our experiences using this technique. Applications and Limitations Any condition that induces a corneal haze or opacity can be objectively assessed using the densitometry approach, provided that the cornea is not opaque.

  • Page 106: Keratic Precipitates

    14 Corneal Optical Densitometry display 14.1 Keratic precipitates A 50-year-old patient presented with a history of granulomatous uveitis due to a toxoplasmosis infection. At initial presentation he had numerous large keratic precipitates deposited on the endothelial surface. In Figure 123 the large precipitates are prominent on the innermost layer of the densitometry scan.
  • Page 107 14 Corneal Optical Densitometry display Figure 125: Corneal Optical Densitometry display showing keratic precipitates after one week of therapy Figure 126: Corneal Optical Densitometry display showing keratic precipitates after two weeks of therapy...

  • Page 108: Position And Depth Of Intacs Rings

    (Figure 127). The depth of the rings can also be seen, measured and followed up over time, and all measurements can be made from a single Pentacam® scan. Figure 127: Corneal Optical Densitometry display showing the position and depth of INTACS ®...

  • Page 109: Dsaek With Specks At The Interface

    14 Corneal Optical Densitometry display 14.3 DSAEK with specks at the interface One of the complications associated with a reduced visual outcome in DSAEK surgery is haze at the interface between the donor cornea and the recipient cornea. The capacity of the densitometry screen to depict any desired layer makes it possible to examine the lamellar interface in greater detail.

  • Page 110: Surgery Outcomes By Arun C. Gulani, Md, Ms

    When looking at a corneal scar our inherent mindset is: “There is the culprit. Let’s eradicate it". What I suggest instead is to study the corneal scar and its impact on vision and the Pentacam® technology, especially its corneal densitometry program is a dominant diagnostic in this direction. It can essentially visualize the scar, its depth in the cornea;...

  • Page 111: Using Pentacam® Technology To Evaluate Corneal Scars, Planning And Documenting

    15 Using Pentacam ® technology to evaluate corneal scars, planning and documenting surgery outcomes Figure 130: Post- and pre-op slit lamp images of an on-cornea scar Figure 131: General Overview showing findings on an in-cornea scar in the Scheimpflug image...
  • Page 112 Figure 132: Pre- and post-op slit lamp images of an in-cornea scar The Pentacam® corneal densitometry function is indispensable to me not only in selecting specific techniques but also as a means of educating my patients with a visual aid that they can understand.
  • Page 113 3.7 D to 0.3 D. After corneal visual rehabilitation, collagen-cross-linking can be used to further stabilize this restored cornea. Here the Pentacam® can be used not only in planning but also in documenting successful outcomes.

  • Page 114: Case 1: Corneal Scar With Rk Incisions And Cataract

    15 Using Pentacam ® technology to evaluate corneal scars, planning and documenting surgery outcomes 15.1 Case 1: Corneal scar with RK incisions and cataract This patient was referred with a central on-corneal scar with multiple RK incisions and cataract. As a first step, he underwent scar peel with excimer laser myopic ablation to clear the cornea and make it measurable.
  • Page 115 15 Using Pentacam ® technology to evaluate corneal scars, planning and documenting surgery outcomes Figure 136: Corneal Optical Densitometry display showing a clear cornea following laser scar peel; cataract present Figure 137: Slit lamp image showing a clear cornea following laser scar peel;...
  • Page 116 15 Using Pentacam ® technology to evaluate corneal scars, planning and documenting surgery outcomes Figure 138: Corneal Optical Densitometry display showing status post cataract surgery with toric lens implant giving 20/20 vision Figure 139: Slit lamp image showing status post cataract surgery with toric lens implant...

  • Page 117: Case 2: Keratoconus With Congenital Cataract, High Myopia And High Astigmatism

    15 Using Pentacam ® technology to evaluate corneal scars, planning and documenting surgery outcomes 15.2 Case 2: Keratoconus with congenital cataract, high myopia and high astigmatism This patient was referred with keratoconus, congenital cataracts, high myopia, high astigmatism and presbyopia. As planned first stage, assymetric INTACS® were implanted in preparation of lens exchange surgery using a toric lens implant in the second stage, which eventually brought the patient to emmetropia and unaided 20/20 vision.
  • Page 118 15 Using Pentacam ® technology to evaluate corneal scars, planning and documenting surgery outcomes Figure 142: Corneal Optical Densitometry display showing the emmetropic outcome after lens exchange surgery; INTACS ® in place. Figure 143: Slit lamp image after lens exchange surgery with an emmetropic outcome;...

  • Page 119: Intacs® Implantation

    16 INTACS ® implantation 16 INTACS ® implantation ® 16.1 Case 1: INTACS implantation by Prof. Michael W. Belin A 27-year-old female was referred by her optometrist because of poor vision OD secondary to keratoconus. Her BSCVA was 20/200 OD and with RGP over-refraction 20/30. The patient complained of poor contact lens tolerance with less than 3 hours of daily wearing time.
  • Page 120 Figure 145: Keratometer values Then a complete Pentacam® anterior segment analysis was performed, revealing the shortcomings of cone location and keratoconus classification based solely on anterior curvature. Both the anterior and posterior elevation map, as well as the pachymetry map locates the cone just...

  • Page 121: Case 2: Intacs® After Prk By Alain-Nicolas Gilg, Md

    (Figure 147). Figure 147: Zernike Analysis topography pre INTACS ® The keratoconus menu of the Pentacam® identifies this cornea as an oblate postoperative cornea. Note the negative eccentricity and the abnormally high aberration coefficient due to the HOA (Figure 148).
  • Page 122 16 INTACS ® implantation Figure 148: Pachymetric showing the pachymetry progression in an oblate postoperative cornea After the implantation of INTACS® her visual acuity was sph +0.50 cyl -1.25 A 30° VA 20/20 „ „ The Scheimpflug image shows a successful fit of the implanted INTACS® (Figure 149).

  • Page 123: Case 3: Intacs® & Crosslinking By Prof. Renato Ambrósio Jr, Fernando Faria-Correia, Md, Allan Luz, Md

    16 INTACS ® implantation 16.3 Case 3: INTACS ® & crosslinking by Prof. Renato Ambrósio Jr, Fernando Faria-Correia, MD, Allan Luz, MD A 24-year-old male patient presented with progressive keratoconus in OS and anisometropia. Uncorrected visual acuity (UCVA) was 20/20 in OD and 20/200 in OS. Wavefront assisted manifest refraction was sph -0.75 cyl -5.25 A 175°, giving 20/30 in OS.

  • Page 124: Intacs® Implantation

    16 INTACS ® implantation Figure 151: Preoperative Scheimpflug image of the vertical section Figure 152: Postoperative Scheimpflug image of the vertical section...

  • Page 125: Holladay Report & Holladay Ekr65 Detail Report By Jack T. Holladay, Md

    17 Holladay Report & Holladay EKR65 Detail Report 17 Holladay Report & Holladay EKR65 Detail Report by Jack T. Holladay, MD 17.1 Holladay Report The Holladay Report was developed together with Jack T. Holladay, MD. The aim was: to improve the calculation of IOL for patients who have undergone previous corneal surgery „...
  • Page 126 17 Holladay Report & Holladay EKR65 Detail Report Then click “Miscellaneous Settings” to confirm all of the other settings. To keep these settings, select “Holladay_Setting” (Figure 154) in the "Load Setting" pull-down menu, then click “Save” and check the “Lock Settings” box. Figure 154: Miscellaneous settings menu Figure 155 shows the map overlay for the corneal thickness map and...
  • Page 127 17 Holladay Report & Holladay EKR65 Detail Report Figure 157: Holladay Report of a normal exam The upper left box in Figure 157 shows the general patient data. The center upper box in [31] Figure 157 shows the Equivalent K-Readings 65 (EKR65) for the 4.5 mm zone along with mean EKR65, astigmatism, Q-value (6 mm zone) and total spherical aberration (SA) [Z(4,0) + Z(6,0) + Z(8,0) for 6.0 mm zone].
  • Page 128 17 Holladay Report & Holladay EKR65 Detail Report The upper left map [axial/sagittal curvature (front)] in Figure 157, shows the axial curvature or power map uses a sph as the reference and the keratometric formula for power (337.5/axial radius in mm). A steel ball with a 7.5 mm radius of curvature would have a uniform power of 45.0 D (337.5/7.5 mm = 45.0 D) at all points.
  • Page 129 17 Holladay Report & Holladay EKR65 Detail Report The central upper map (corneal thickness) in Figure 157, shows that the shape of a normal cornea is a negative meniscus lens (i.e., the back surface radius of curvature is steeper than the front) which is thinnest at its optical center and thickens by the square of the distance from the center.
  • Page 130 17 Holladay Report & Holladay EKR65 Detail Report Front elevation near min RP* Maximum front elevation* elevation upper limit elevation upper limit (μm) (μm) (μm) (μm) mean +1.0 mean +1.0 +2.1 +3.1 +1.3 +4.3 +2 SD +4.2 +5.2 +2 SD +2.6 +5.5 +3 SD...

  • Page 131: Holladay Ekr65 Detail Report

    17 Holladay Report & Holladay EKR65 Detail Report 17.2 Holladay EKR65 Detail Report Figure 158: Holladay EKR65 Detail Report of a normal exam The upper box in Figure 158, shows the demographic information regarding the patient is in the box at the top of the Page 2.

  • Page 132: Case 1: Holladay Report & Holladay Ekr65 Detail Report Of A Normal Exam

    17 Holladay Report & Holladay EKR65 Detail Report The lower central table in Figure 158, shows the EKR65 mean, is the weighted mean where 65% of the values are represented using the smallest range of points. In the above graph this value is 40.76 D (40.8 D) for the range indicated.
  • Page 133 17 Holladay Report & Holladay EKR65 Detail Report The EKR65 values at the top center (Figure 159) are approximately 3.0 D flatter than average with 1.31 D of astigmatism. In the axial power map corneal power is steeper above than it is below by around 1.0 D, which is not unusual.
  • Page 134 17 Holladay Report & Holladay EKR65 Detail Report Figure 160: Holladay EKR65 Detail Report of a normal exam With a normal pupil of 5.48 mm the 4.5 mm grey column, with EKR65 flat K1 = 40.11 A 161° and steep K2 = 41.42 A 71° (Figure 160), would provide the correct keratometric values to enter into an IOL calculator for the proper spheroequivalent power and toricity of the IOL.

  • Page 135: Case 2: Holladay Report & Holladay Ekr65 Detail Report Of A Keratoconus Exam

    17 Holladay Report & Holladay EKR65 Detail Report 17.4 Case 2: Holladay Report & Holladay EKR65 Detail Report of a keratoconus exam Figure 161: Holladay Report from a keratoconus exam The axial power map scale is centered at 43.0 D (green), which is normal. The axial and tangential curvature maps show a “hot spot”...
  • Page 136 17 Holladay Report & Holladay EKR65 Detail Report Figure 162: Holladay EKR65 Detail Report from a keratoconus exam The distribution of EKR is a bimodal (2 peaks) (Figure 162) distribution, and the EKR65 of 42.63 D is 0.57 D less than the 43.20 D peak. Standard keratometry usually measures nearer the peak and will over-estimate the power in keratoconus, leaving the patient with a hyperopic surprise.

  • Page 137: Case 3: Holladay Report & Holladay Ekr65 Detail Report Of A Post Lasik Exam

    17 Holladay Report & Holladay EKR65 Detail Report 17.5 Case 3: Holladay Report & Holladay EKR65 Detail Report of a post LASIK exam Figure 163: Holladay Report of a post LASIK exam The mean value of the color scale (green) is 39.0 D, which is 4.5 D flatter than normal, and the semi- meridian lines are extremely segmented, demonstrating a large amount of irregular astigmatism.
  • Page 138 17 Holladay Report & Holladay EKR65 Detail Report Figure 164: Holladay EKR65 Detail Report of a post LASIK exam The EKR65 mean is 35.63 D at the 4.5 mm zone and 35.27 D at the 3.0 mm zone (Figure 164). The pupil diameter was 2.94 mm and confirmed with scotopic pupillometry done with another device.

  • Page 139: Corneal Tomographic Analysis Is Essential Before Cataract Surgery - 4 Steps In Screening Candidates For Premium Iols By Prof. Naoyuki Maeda

    This article explains on the basis of case examples how the Pentacam® can be used for assessing corneal optical quality for the selection of premium IOLs. In the process it conveys the importance of corneal tomographic screening before cataract surgery.
  • Page 140 - 4 steps in screening candidates for premium IOLs The Pentacam® is a Scheimpflug based corneal tomographer. We have been able to develop a program which makes it easy to perform the 4 steps of the screening procedure as described above.
  • Page 141 18 Corneal tomographic analysis is essential before cataract surgery - 4 steps in screening candidates for premium IOLs Figure 166: Cataract Pre-OP Display moderate keratoconus Total HOA (1.575 μm) is high, and SA (-1.355 μm) is too low. Conventional spherical IOL is recommended after obtaining the patient’s informed consent regarding the effects of corneal irregular astigmatism on quality of vision.

  • Page 142: Step 1: Evaluation Of Corneal Irregular Astigmatism

    18 Corneal tomographic analysis is essential before cataract surgery - 4 steps in screening candidates for premium IOLs 18.2 Step 1: Evaluation of corneal irregular astigmatism Although there is no inherent problem in performing cataract surgery in patients with mild pterygium, subclinical keratoconus, or mild corneal scar, it is possible for irregular astigmatism associated with these corneal diseases to affect the quality of vision of the eye after surgery [40].

  • Page 143: Dependency Of Effective Phacoemulsification Time On Pentacam ® Nucleus Staging (Pns) By Mehdi Shajari Md, Wolfgang Mayer Md, Prof. Thomas Kohnen

    Prof. Thomas Kohnen 19.1 Introduction The Pentacam® HR Scheimpflug imaging system can be used for cataract grading with the Pentacam® nucleus staging (PNS) classification. It evaluates the optical density of the lens by analyzing the backward scatter. For reliable results it is critical to perform the examination when the eye is dilated.

  • Page 144: Case 1: Low Pns And Low Ept

    In OD of this caucasian female patient it can be seen by the relatively high scatter that the lens is not clear. Accordingly, the Pentacam® shows a PNS of 1. Please note also the overview of further details on lens opacification such as average and maximum density. For this patient an EPT of 2.99 seconds was calculated.

  • Page 145: Total Corneal Astigmatism For Toric Iol By Giacomo Savini, Md

    However this has been demonstrated only recently [48]. Using the Pentacam® TCRP (i.e. the TCA) to calculate the required cylinder of toric IOLs we were able to lower the error in refractive astigmatism after cataract surgery as compared to calculations based on KA.

  • Page 146: Case 1: Cylinder Overcorrection From Measurement Of Keratometric Astigmatism In An Eye With Wtra

    A 51-year-old woman underwent cataract extraction in OD. Her refraction was sph +4.00 cyl +0.75 A 100°. Axial length was 20.03 mm, and a +33.00 D toric Acrysof (Alcon, Fort Worth, TX) was calculated for emmetropia. The Pentacam® detected a WTRA whose measurements at 3 mm (Figure 170, Figure 171) yielded a 0.8 D difference between KA (1.4 D 110.8°) and TCRP astigmatism,...
  • Page 147 20 Total corneal astigmatism for toric IOL Figure 171: Corneal Power Distribution display showing a lower amount of astigmatism, at 0.6 D 114.9° The choice of the IOL was between the SN6AT3 and the SN6AT4 models (the T2 model was not available).

  • Page 148: Case 2: Cylinder Undercorrection From Measurement Of Keratometric Astigmatism In An Eye With Atra

    An 85-year-old man underwent cataract surgery in OS. Axial length was 23.31 mm, and a 21.50 D toric Acrysof was calculated for emmetropia. Traditional KA measurement (Figure 172) showed a value of 1.9 161°, which was significantly lower than the Pentacam® TCRP at 3 mm (Figure 173), measuring 2.8 D 160.3°.

  • Page 149: Case 3: Cylinder Overcorrection From Measurement Of Keratometric Astigmatism

    A 71-year-old man underwent cataract surgery in OS. Axial length was 22.87 mm and a 23.50 D toric Acrysof was calculated for emmetropia. Traditional KA measurement (Figure 174) showed a value of 1.9 D 79.2°, which was significantly higher than the Pentacam® TCRP at 3 mm (Figure 175), measuring 1.2 D 74°.
  • Page 150 20 Total corneal astigmatism for toric IOL Figure 175: Corneal Power Distribution display showing a TCRP astigmatism of 1.2 D 74°, i.e. lower than KA astigmatism We aimed to correct the TCA and considering a surgically induced astigmatism of 0.2 D 90°, we targeted a correction of 1.37 D 76°.

  • Page 151: Overview About Iol Power Calculation Formulas For Different Eye Types

    21 Overview about IOL power calculation formulas for different eye types 21 Overview about IOL power calculation formulas for different eye types patient group IOL-calculator/formula where to find value paper normal eyes standard historical Cataract Pre-OP Display Sim K's and other Scheimpflug Corneal Power methods (SRK I;...

  • Page 152: Phakic Iol Implantation

    She complained of poor contact lens tolerance with less than 4 hours of daily wearing time. We discussed several treatments and the possibility of implanting a pIOL. The Pentacam® allows us to measure very easily and accurately the anterior chamber and so determine if there is enough space to implant an iris-fixated Artisan phakic IOL.

  • Page 153: Postoperative Evaluation

    22 Phakic IOL implantation 22.1.2 Postoperative evaluation The Scheimpflug image shown below displays the same case after successful Artisan pIOL implantation. It is evident there is space from the anterior pIOL surface to the endothelium centrally and at the periphery (Figure 177).
  • Page 154 22 Phakic IOL implantation Her pupil sizes were: scotopic: OD 6.24 mm, OS 6.27 mm „ „ mesopic low: OD 4.74 mm, OS 4.78 mm „ „ mesopic high: OD 3.62 mm, OS 3.56 mm. „ „ Because of her high ametropia, LASIK and PRK were not an option. Therefore we checked the possibility of a pIOL implantation.
  • Page 155 A possible consequence would be endothelial cell loss, a risk that must be taken into account and avoided. For this purpose the Pentacam® offers unique aging prediction software which simulates the position of the pIOL after 10, 15 or 20 years.
  • Page 156 10 or 20 years, we decided not to perform the surgery. This case demonstrates the big advantage of the Pentacam® in daily clinical practice. Without even touching the patient’s eye we were able to make a competent diagnosis and decision followed by thorough...

  • Page 157: Toric Artisan/Verisyse, 5/8.5 Mm

    IOP was 16 mmHg in both eyes. We counted 2318 cells/mm² in OD and 2418 cells/mm² in OS. We used the Pentacam® 3D pIOL Simulation and Aging Prediction to simulate the fit of the pIOL and to check its position over the course of years following surgery using the aging prediction module.
  • Page 158 22 Phakic IOL implantation Since the patient was only 22 years old, we wanted to check the pIOL position as to be on the safe side. We checked the predicted pIOL position at 40 years after surgery (Figure 182). Here the simulated minimum clearance is 1 mm.

  • Page 159: Patient Selection Criteria By Prof. Burkhard Dick, Sabine Buchner, Optometrist

    1070 μm; The cornea and crystalline lens should be clear; „ „ Iris convexity: If the iris is very irregular, it is better to refrain from pIOL surgery. The Pentacam® „ „ pIOL simulation in Figure 184 shows an iris convexity of more than 15 degrees.
  • Page 160 22 Phakic IOL implantation Figure 184: 3D pIOL Simulation and Aging Prediction showing a large iris convexity The following warning appears: “Automatic pIOL alignment may be negatively influenced by large iris convexity”.

  • Page 161: Case Example Of Ectasia After Lasik, Crosslinking And Piol Implantation By Prof. Renato Ambrósio Jr, Fernando Faria-Correia, Md, Allan Luz, Md

    22 Phakic IOL implantation 22.4 Case example of ectasia after LASIK, crosslinking and pIOL implantation by Prof. Renato Ambrósio Jr, Fernando Faria-Correia, MD, Allan Luz, MD A 25-year-old male patient presented with severe and progressive visual loss (UCVA of counting fingers at 1 m in both eyes) due to ectasia (Figure 185) following bilateral LASIK in 2006.
  • Page 162 22 Phakic IOL implantation Clinical case of post-LASIK ectasia treated by transepithelial crosslinking followed by phakic intraocular lens implantation in both eyes. Figure 186: Scheimpflug Image after transepithelial crosslinking in OD (A) and OS (B), slit-lamp photograph showing pIOL implant in OD (C) and OS (D)

  • Page 163: Case Reports From Daily Practice

    23 Case reports from daily practice Case reports from daily practice 23.1 Case 1: Cortical cataract by Tobias H. Neuhann, MD A 23-year-old, -12.5 D myopic white female underwent a fundus examination at a local eye clinic. Her BSCVA was 20/30, while her best corrected visual acuity with contact lenses was not documented.

  • Page 164: Case 2: Remove Sutures After Corneal Transplant Surgery? By Tobias H. Neuhann, Md

    Tobias H. Neuhann, MD A 22-year-old white male had received a corneal transplant due to keratoconus 12 months earlier. The first suture had already been removed. Examination with the Pentacam® revealed only a small degree of corneal astigmatism (Figure 189), but also a peripheral hot spot (black circle).

  • Page 165: Case 3: Keratoconus And Cataract By Tobias H. Neuhann, Md

    Case 3: Keratoconus and cataract by Tobias H. Neuhann, MD A 54-year-old male asked for glasses. BSCVA was 20/80 in both eyes. The Pentacam® delivered the solution in two seconds. The right eye had a cataract and undetected keratoconus (Figure 190, Figure 192).
  • Page 166 23 Case reports from daily practice Figure 193: 4 Maps Refractive of OS Figure 194: Pachymetry progression in OS Figure 195: Scheimpflug image of OS...
  • Page 167 Which K reading should we use for the IOL calculation? Figure 196: Topography of the central part of the cornea The Pentacam® gives us an actually measurement ot the central power of the cornea. We used 42.9 for both K1 and K2 (Figure 196).

  • Page 168: Case 4: Corneal Infiltrate By Prof. Renato Ambrósio Jr

    6 hours in OS. She woke up in the next night with moderate secretion. She complained of photophobia and blurred vision in OS when wearing glasses. A Pentacam® examination was performed in both eyes, revealing an infiltrate in OS, and the findings were with...
  • Page 169 Figure 199: Scheimpflug Image of acorneal infiltrate 3 days later Figure 200: Slit lamp photo of the same corneal infiltrate 3 days later When the Pentacam® examination was repeated on day 3, the infiltrate was found to have decreased, as seen in the Scheimpflug and slit lamp biomicroscopy images (Figure 199, Figure 200).

  • Page 170: Case 5: Incisional Edema By Prof. Renato Ambrósio Jr

    23 Case reports from daily practice 23.5 Case 5: Incisional edema by Prof. Renato Ambrósio Jr A 76-year-old female patient presented with incisional edema 12 months after phacoemulsification. Endothelial morphology revealed large cells with pleomorphism and polymegathism. Central cell count was 1.079 cells/mm². Figure 201: Slit lamp photo showing incisional edema Figure 202: Scheimpflug Image showing incisional edema...

  • Page 171: Case 6: Corneal Thinning After Herpetic Keratitis By Prof. Renato Ambrósio Jr

    23 Case reports from daily practice A slit lamp exam and a Pentacam® exam were performed, and the findings were correlated with each other (Figure 201, Figure 202). The central cornea was clear with no edema. The peripheral cornea at the incision location was edematous, with formation of small bullae on the surface.
  • Page 172 23 Case reports from daily practice Figure 204: General Overview display revealing corneal thinning A Pentacam® exam is useful for documenting corneal thickness. The thinnest spot is displayed in the pachymetry map and can also be seen in the Scheimpflug images, facilitating follow-up examination (Figure 204).

  • Page 173: Case 7: Epithelial Ingrowth After Keratomileusis In Situ By Prof. Renato Ambrósio Jr

    OD. Figure 205: Slit lamp photo revealed epithelial ingrowth Figure 206: Tomography confirming epithelial ingrowth Epithelial ingrowth was also easily seen in the Pentacam® Tomography (Figure 206).
  • Page 174 The pachymetry map in the 4 Maps Refractive (Figure 207) showed this effect as well, even in the presence of an opaque cornea. The Pentacam® was useful for evaluating corneal elevation, curvature, thickness and opacity. Figure 207: Part of 4 Maps Refractive confirming epithelial ingrowth...

  • Page 175: Scheimpflug And Slit Lamp Images

    24 Scheimpflug and slit lamp images Scheimpflug and slit lamp images 24.1 Corneal dystrophy Figure 208: Scheimpflug image revealing, corneal dystrophy on the posterior surface Figure 209: Slit lamp photo documenting corneal dystrophy on the posterior surface...

  • Page 176: Congenital Anterior Pyramid Cataract

    24 Scheimpflug and slit lamp images 24.2 Congenital anterior pyramid cataract Figure 210: Scheimpflug image showing an anterior pyramid cataract Figure 211: Slit lamp photo showing an anterior pyramid cataract...

  • Page 177: Posterior Capsular Cataract

    24 Scheimpflug and slit lamp images 24.3 Posterior capsular cataract Figure 212: Scheimpflug image showing a posterior capsular cataract Figure 213: Slit lamp photo showing a posterior capsular cataract...

  • Page 178: Nuclear Cataract

    24 Scheimpflug and slit lamp images 24.4 Nuclear cataract Figure 214: Scheimpflug image showing a nuclear cataract Figure 215: Slit lamp photo showing a nuclear cataract...

  • Page 179: Posterior Synechia

    24 Scheimpflug and slit lamp images 24.5 Posterior synechia Figure 216: Scheimpflug image showing posterior synechia Figure 217: Slit lamp photo showing posterior synechia...

  • Page 180: Pterygium

    24 Scheimpflug and slit lamp images 24.6 Pterygium Figure 218: Scheimpflug image in 190° showing a case of pterygium Figure 219: Topography revealing pterygium Figure 220: Slit lamp photo of an eye with pterygium...

  • Page 181: Orthokeratology, General Screening By Alain-Nicolas Gilg, Md

    -1.00 „ „ The Pentacam® Show 2 Exams display showed an optimal eccentricity on the 30° meridian of both eyes, namely 0.50 in OD and 0.49 in OS, permitting us to propose an orthokeratology treatment to this patient (Figure 221).
  • Page 182 25 Orthokeratology, general screening The patient was examined 4 times within 2 months to follow up the condition of the cornea, and the efficacy of the treatment was confirmed by a comparison of all four exams (Figure 222). Figure 222: Compare 4 Exams, one prior and three after orthokeratology...
  • Page 183 Examination with the Pentacam® using the Compare 2 Exams display confirmed that the effect of the ortho-K lens was reversed during the day, and so it was decided to fit the patient with a more...

  • Page 184: Important Studies And Case Reports

    Ní Dhubhghaill MB PhD, Jos J. Rozema MSc PhD, Sien Jongenelen MD, Irene Ruiz Hidalgo MSc, Nadia Zakaria MD PhD, Marie-José Tassignon, MD PhD.) - IOVS Papers in Press. Published on December 10, 2013 as Manuscript iovs.13-13236 Anterior segment parameters in Indian young adults using the Pentacam® – (Seyed Mahdi Ahmadi „ „...
  • Page 185 – (Georgios Labiris, MD, PhD, Athanassios Giarmoukakis, MD, Haris Sideroudi, PhD; Panagiota Bougatsou, MD, Ilias Lazaridis, MD, Vassilios P. Kozobolis, MD, PhD) - J Cataract Refract Surg. 2012; 38:1616–1625 Q 2012 ASCRS and ESCRS Pentacam® based phototherapeutic keratectomy outcome in superficial corneal opacities – „ „...
  • Page 186 Shihao Chen MD, ODa, Thomas Wright BPsyc (Hons)a, Xiaoyu Wang MDa, Yini Li MDa and Qinmei Wang MD) - J Cataract Refract Surg. 2011; 37:341–348 Q 2011 ASCRS and ESCRS Posterior Corneal Elevation After LASIK With Three Flap Techniques as Measured by Pentacam® „...
  • Page 187 Central Corneal Thickness, Anterior Chamber Depth, and Pupil Diameter Measurements Using „ „ Visante OCT, Orbscan, and Pentacam® – (Ahmet Taylan Yazici, MD; Ercument Bozkurt, MD; Cengiz Alagoz, MD; Nese Alagoz, MD; Gokhan Pekel, MD; Vedat Kaya, MD; Omer Faruk Yilmaz, MD) - J Refract Surg. 2010;26:127-133...
  • Page 188 „ Renato Ambrósio, Jr, MD, PhD; Marcella Salomão, MD; Guillermo C. Velarde, DSc; Walton Nosé, MD) - J Refract Surg. 2010;26(9):677-681 Pentacam® Scheimpflug Evaluation of Corneal Volume After LASIK – (Camila M. Gadelha P. Diniz, „ „ MD; Rossen M. Hazarbassanov, MD; Ester Yamazaki, MD; Celina Murata, MD; Felipe Mallmann, MD;...
  • Page 189 Surgery – (Sun Woong Kim, MD; Hae Jung Sun, MD; Jee Ho Chang, MD; Eung Kweon Kim, MD, PhD) - J Refract Surg. 2009;25:1091-1097 Location of Steepest Corneal Area of Cone in Keratoconus Stratifi ed by Age Using Pentacam® - „...
  • Page 190 Repeatability and concordance of the Pentacam® system. Comparative study of corneal parameters „ „ measured with Pentacam® and Atlas – (B. Doménech, D. Mas, E. Ronda, J. Pérez, J. Espinosa, C. Illueca) - Optica Pura Y Aplicada 2009; 42(1):51-60 2008 Diurnal Variation of Axial Length, Intraocular Pressure, and Anterior Eye Biometrics –...
  • Page 191 Effect of Proparacaine on Central Corneal Thickness Values. An Evaluation Using Noncontact „ „ Specular Microscopy and Pentacam® – (Andrew K. C. Lam, PhD, FAAO and Davie Chen, BSc(Hons)) - Cornea Volume 26, Number 1, January 2007 PIOL Simulation for High Res Imaging This software provides preoperative detection of post- „...
  • Page 192 26 Important studies and case reports Intrasession and intersession repeatability of the Pentacam® system on posterior corneal assess- „ „ ment in the normal human eye – (Davie Chen, Andrew K.C. Lam, PhD, FAAO) - J Cataract Refract Surg. 2007; 33:448–454. doi:10.1016/j.jcrs.2006.11.008 Keratoconus: It Is Hard to Define, But –...

  • Page 193: Case Reports

    26 Important studies and case reports 26.2 Case reports: Corneal Ectasia After LASIK Despite Low Preoperative Risk: Tomographic and Biomechanical Findings „ „ in the Unoperated, Stable, Fellow Eye – (Renato Ambrósio, Jr, MD, PhD; Daniel G. Dawson, MD; Marcella Salomão, MD; Frederico P. Guerra, MD; Ana Laura C. Caiado, MD; Michael W. Belin, MD) Rotating Scheimpflug imaging system assists in diagnosis of posterior polymorphous corneal „...
  • Page 194 26 Important studies and case reports Scheimpflug analysis of corneal power changes after myopic excimer laser surgery – (Giacomo „ „ Savini, MD, Kenneth J. Hoffer, MD, Michele Carbonelli, MD, Piero Barboni, MD) - J Cataract Re- fract Surg. 2013; 39:605–610 Q 2013 ASCRS and ESCRS Comparison of methods to measure corneal power for intraocular lens power calculation using a „...
  • Page 195 Wang Yan, MD, PhD, Mohamed S. Shaheen, MD, PhD, Charles McGhee, MD, PhD, Naoyuki Maeda, MD, Tobias H. Neuhann, MD, H. Burkhard Dick, MD, PhD, Saleh A. Alageel, MD, FRCS, Andreas Steinmueller) - Saudi Journal of Ophthalmology (2011) 25, 255–259 Comparison of Anterior Chamber Depth Measurements Conducted With Pentacam® HR and IOL- „ „...
  • Page 196 Repeatability and concordance of the Pentacam® system. Comparative study of corneal parame- „ „ ters measured with Pentacam® and Atlas – (B. Doménech, D. Mas, E. Ronda, J. Pérez, J. Espinosa, C) - Optica Pura Y Aplicada 2009; 42(1):51-60 The Comparison of Central and Mean True-Net Power (Pentacam®) in Calculating IOL-Power „...
  • Page 197 25 Important studies and case reports Correlation of lens density measured using Pentacam® Scheimpflug system with LOCS III grading „ „ score and visual acuity in age-related nuclear cataract – (Xueting Pei, Yongzhen Bao, Yi Chen and Xiaoxin Li) - Br. J. Ophthalmol. published online 27 Jun 2008. doi:10.1136/bjo.2007.136978 Alterations in the anterior chamber angle after implantation of iris-fixated phakic intraocular „...

  • Page 198: Case Reports

    (Wolf Buehl, MD, Danijela Stojanac, MD, Stefan Sacu, MD, Wolfgang Drexler, MD, Oliver Findl, MD) - American Journal of Ophthalmology 8 January 2006 2005 Validity and Repeatability of Anterior Chamber Depth Measurements with Pentacam® and Orbscan „ „ – (Birgit Lackner, MD, Gerald Schmidinger, MD, and Christian Skorpik, MD) - Optometry and Vision Science, Vol.
  • Page 199 Asli Dinc, banu Oncel, Ebru Gorgun, Levent) - European Journal of Ophthalmology 2009; 19(3): 411-415 1120-6721/411-05 2008 Anterior Chamber Measurements by Pentacam® and AS-OCT in Eyes With Normal Open Angles - „ „ (Jeong-Ho Yi, MD, Samin Hong, MD, Gong Je Seong, MD, PhD, Sung Yong Kang, MD, Kyoung Tak Ma, MD, Chan Yun Kim, MD, PhD) - Korean Journal of Ophthalmology 2008;22:242-245;...

  • Page 200: Case Reports

    The role of Scheimpflug imaging in the management of posterior scleriti – (Natalia Pawlowska „ „ Jonathan Luck) - Eye and Brain 2010:2 43–46 Assessment of capsular block syndrome with Scheimpflug camera Pentacam® Scheimpflug system „ „ with LOCS III grading score and visual acuity in age-related nuclear cataract – (Yongzhen Bao, Yi Chen and Xiaoxin Li Br) - J.

  • Page 201: References

    4. Jain R, Grewal D, Grewal SP. Quantitative analysis of anterior chamber following peripheral laser iridotomy using Pentacam® in eyes with primary angle closure. Eur J Ophthalmol. 2012 May 14:0 5. Ambrósio R Jr, Alonso RS, Luz A, Velarde LGC. Corneal-thickness spatial profile and corneal- volume distribution: Tomographic indices to detect keratoconus.
  • Page 202 27 References 19. Ambrosio R Jr, Dawson DG, Salomao M, et al. Corneal ectasia after LASIK despite low preoperative risk: tomographic and biomechanical findings in the unoperated, stable, fellow eye. J Refract Surg 2010; 26(11):906-11 20. Ambrosio R Jr, Randleman JB. Screening for ectasia risk: what are we screening for and how should we screen for it? J Refract Surg 2013;29(4):230-2 21.
  • Page 203 27 References 38. Li Wang, MD, PhD, Douglas D. Koch, MD. Custom optimization of intraocular lens asphericity. J Cataract Refract Surg 2007; 33:1713–1720 39. Holladay JT. Exact Toric IOL Calculations Using Currently Available Lens Constants. Arch Ophthalmol. Holladay JT 2012;130(7): 946-7 40.

  • Page 204: List Of Illustrations

    Figure 35: 4 Maps Selectable revealing there to be no post-LASIK ectasia..................34 Figure 36: Orbscan® 4 maps incorrectly suggesting ectasia in OD....................... 35 Figure 37: Pentacam® 4 Maps Selectable revealing there to be no post-LASIK ectasia..............35 Figure 38: 4 Maps Refractive revealing a thick cornea..........................36 Figure 39: HRT image......................................36...
  • Page 205 28 List of illustrations Figure 53: 24-2 Humphrey visual field showing an early inferior paracentral defect in OS............44 Figure 54: Spectral domain OCT showing abnormal RNFL thickness inferiorly in OD, corresponding to the early superior arcuate defect in that eye (also look Figure 52)..........44 Figure 55: Scheimpflug Image showing very low ACV, shallow ACD, narrow ACA and anterior vaulting of the lens in OD................................
  • Page 206 28 List of illustrations Figure 104: BFS-based elevation map of an astigmatic eye........................85 Figure 105: Elevation map of a keratoconic cornea..........................86 Figure 106: Elevation superimposed on an astigmatic pattern....................... 86 Figure 107: Elevation map of a keratoconic cornea using an enhanced reference shape with an exclusion zone to improve detectability..............................

  • Page 207: List Of Illustrations

    28 List of illustrations Figure 147: Zernike Analysis topography pre INTACS®..........................119 Figure 148: Pachymetric showing the pachymetry progression in an oblate postoperative cornea..........120 Figure 149: Scheimpflug Image after INTACS® implantation........................120 Figure 150: Preoperative, postoperative (6 weeks after femtosecond-assisted intracorneal ring segment and transepithelial crosslinking) and subtraction maps of the average optical density and axial curvature maps........................................
  • Page 208 28 List of illustrations Figure 196: Topography of the central part of the cornea........................165 Figure 197: Scheimpflug Image of a corneal infiltrate..........................166 Figure 198: Slit lamp photo of the same corneal infiltrate........................166 Figure 199: Scheimpflug Image of acorneal infiltrate 3 days later......................167 Figure 200: Slit lamp photo of the same corneal infiltrate 3 days later.....................167 Figure 201: Slit lamp photo showing incisional edema...........................168 Figure 202: Scheimpflug Image showing incisional edema........................168...

  • Page 209: Tables Directory

    29 Tables directory 29 Tables directory Table 1: Central keratometry (front) (*N = 1243 normal eyes, internal, unpublished data by J. T. Holladay)....126 Table 2: Maximum tangential K (front) (*N = 1243 normal eyes, internal, unpublished data by J. T. Holladay)..126 Table 3: Thinnest pachymetry (*N = 1243 normal eyes, internal, unpublished data by J.

  • Page 210: List Of Abbreviations

    30 List of abbreviations 30 List of abbreviations axis „ „ anterior chamber angle „ „ anterior chamber depth „ „ anterior chamber volume „ „ ATRA against the rule astigmatism „ „ best fit ellipse „ „ best fit sphere „...

  • Page 211: List Of Abbreviations

    30 List of abbreviations penetrating keratoplasty „ „ pellucid marginal degeneration „ „ Pentacam® nucleus staging „ „ photorefractive keratectomy „ „ phototherapeutic keratectomy „ „ Quality Specification „ „ radius „ „ RGPCL rigid gas permeable contact lens „...

  • Page 212: Authors And Contact Addresses

    Tucson, Arizona 85711, USA Fax: +1-713 669 9153 Email: mwbelin@aol.com Email: holladay@docholladay.com Ina Conrad-Hengerer, MD Jörg Iwanczuk, Graduate Engineer Privatpraxis für Augenheilkunde OCULUS Optikgeräte GmbH Eichenstr. 3 Münchholzhäuser Str. 29 65468 Trebur, Germany 35582 Wetzlar, Germany Phone: +49-(0)6147-502180 Phone: +49-(0)641-2005-0...
  • Page 213 31 Authors and contact addresses Tobias H. Neuhann, MD Clinical Director AaM Augenklinik am Marienplatz Marienplatz 18/19 80331 Munich, Germany Phone: +49-(0)89-230 8890 Fax: +49-(0)89-230 88910 Email: sekretariat@a-a-m.de www.augenklinik-marienplatz.de Jos J. Rozema, MSc, PhD Department of Ophthalmology Antwerp University Hospital Wilrijkstraat 10 2650 Edegem, Belgium Email: Jos.Rozema@uza.be...
  • Page 214 The following pages remain free and offer space for personal notes...
  • Page 216 GERMANY • • Tel. +49-641-2005-0 Fax +49-641-2005-295 • E-Mail: export@oculus.de www.oculus.de • • OCULUS USA, info@oculususa.com • OCULUS Asia, info@oculus.hk • OCULUS Czechia, oculus@oculus.cz • OCULUS Iberia, info@oculus.es • OCULUS Poland, biuro@oculus.pl • OCULUS Slovakia, office@oculus.sk • OCULUS Turkey, info@oculus-turkey.com.tr...

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