OCULUS Pentacam Interpretation Guide

1
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
3.5 Equivalent Keratometer Readings power map.........................................................................................10
3.6 Total Cornea Refractive Power map............................................................................................................11
4 Recommended settings and color maps, displays and values....................................................12-14
4.1 Recommended settings...................................................................................................................................12
4.2 Recommended color maps, displays and values......................................................................................13
4.2.1 Screening for corneal refractive surgery.......................................................................................13
4.2.2 Pre-op screening for iris fixated phakic IOL implantation.......................................................13
4.2.3 Glaucoma screening............................................................................................................................14
4.2.4 Cataract surgery and IOL calculation for virgin and post refractive corneas....................14
5 Differences between Placido and elevation-derived curvature maps
by Prof. Michael W. Belin....................................................................................................................15-19
5.1 Keratoconus in OD and OS?..................................................................................................................... .....15
5.2 Form fruste keratoconus?.......................................................................................................................... ....18
6 Fast Screening Report as a first step in examining a patient and evaluating
one’s findings by Ina Conrad-Hengerer, MD................................................................................. 20-27
6.1 Case 1: Unilateral high astigmatism with suspicion of bilateral keratoconus...............................20
6.2 Case 2: Fuchs’ dystrophy with DMEK cataract surgery – progress evaluation...............................23
6.3 Case 3: Corneal injury sustained from an eye drop bottle after cataract surgery.........................26
7 Refractive Power Distribution display by Ina Conrad-Hengerer, MD.......................................28-30
7.1 Visual acuity impairment during nighttime driving with distance spectacles –
nocturnal myopia? ........................................................................................................................................... 28
8 Corneal ectasia.....................................................................................................................................31-35
8.1 Case 1: Ectasia after radial keratotomy by Prof. Renato Ambrósio Jr .............................................31
8.2 Case 2: Ectasia after LASIK? by Prof. Michael W. Belin.........................................................................33
9 Glaucoma...............................................................................................................................................36-46
9.1 Case 1: General screening by Tobias H. Neuhann, MD..........................................................................36
9.2 Case 2: YAG laser iridectomy by Eduardo Viteri, MD.............................................................................37
9.3 Screening for narrow angles by Dilraj S. Grewal, MD...........................................................................39
9.3.1 Case 1.....................................................................................................................................................39
9.3.2 Case 2.....................................................................................................................................................42
9.4 Evaluating the anterior segment in phacomorphic glaucoma by Dilraj S. Grewal, MD..................45
Table of contents

OCULUS Pentacam Specifications

General

Measurement Time	Less than 2 seconds
Corneal Coverage	Up to 12 mm
Software	Pentacam Software
Data Transfer	USB
Corneal Topography	Yes
Display	External monitor required
Measurement Principle	Scheimpflug imaging
Camera	Rotating Scheimpflug camera
Light Source	Blue LED
Pachymetry	Yes
Anterior Chamber Analysis	Yes
Imaging Principle	Scheimpflug imaging
Fixation	Internal
Power Supply	100-240 V, 50/60 Hz
Resolution	High resolution
Lens Density Measurement	Yes
Dimensions	Varies depending on model and configuration
Weight	Varies by model, check manufacturer specifications
Number of Images	25 or 50