Presenting And Chief Author Dr. Seema Bhosale, Co-Author Dr. Vijay Shetty, Dr. Suhas Haldipurkar, Dr. Ravish Vaishnav.

1. EVALUATION OF
PACHYMETRY,PROGRESSION INDEX AND
BACK DIFFERENCE ELEVATION VALUES IN
PATIENTS OF KERATOCONUS
E- POSTER 0235
Presenting and Chief author Dr. Seema Bhosale
Co-author Dr. Vijay Shetty
Dr. Suhas Haldipurkar
Dr. Ravish Vaishnav

2. FINANCIAL DISCLOSURE
None of the authors have any financial interest in
any products mentioned in this study

3. Introduction
• Keratoconus(KC)is a non inflammatory ectatic corneal dystrophy
characterized by a usually progressive corneal thinning that results in
corneal steepening,protrusion and irregular astigmatism1
• Elevation based Scheimpflug imaging is used for the diagnostic
characterization of the front and back corneal shape, along with
pachymetric mapping2
• The Enhanced Best Fit Sphere(Reference shape) utilized in the
Belin/Ambrosio Enhanced Ectasia display provides the back difference
elevation values extrapolated from the difference maps3
• 1
Rabinowitz YS. Keratoconus. Surv Ophthalmol. 1998;42:297–319
• 2
Ucakhan OO, Cetinkor V, Ozkan M, Kanpolat A. Evaluation of Scheimpflug imaging parameters in subclinical keratoconus,
keratoconus, and normal eyes. J Cataract Refract Surg. 2011;37(6):1116–1124
3Belin MW, Khachikian SS. Keratoconus / Ectasia Detection with the Oculus Pentacam: Belin / Ambrósio
Enhanced Ectasia Display . Highlights of Ophthalmology. 2009; 35(6):5-12.

4. Purpose
• To evaluate the change in pachymetry, progression
index, front and back elevation points and back
difference elevation values in patients of different
grades of keratoconus

5. Materials and Methods
• Study site : Tertiary eye institute in Western Maharashtra
• Study design : Secondary data analyses
• Time frame : Conducted between February 2012 – April 2016
• Sample Size :80 eyes of 42 patients of Keratoconus, 30 eyes of 15
normals
• Inclusion criteria : All Patients diagnosed of Keratoconus in the
study period
• Exclusion criteria : Patients of Keratoconus who had undergone
treatment elsewhere and patients who had any other additional
corneal pathology

6. Materials and Methods
• Methodology :
- All patients underwent ophthalmic examination(Keratometry,
Manifest Refraction, Slit lamp biomicroscopy) and Pentacam
measurements of the first visit.
- The patients were divided into grades according to
Amsler-Krumeich classification.
- Pachymetry at the apex(PA) and at the thinnest location(PT) with
difference in the distance between PA and PT, Progression Index
(PI), front and back elevation points and back difference elevation
values were obtained from the Pentacam.
- The back difference elevation values were extrapolated from the
difference maps of the Belin-Ambrosió enhanced ectasia display
of the system.

7. Results
Pachymetry in
all groups
F value P Value
PA 22.32 0.000
PT 19.51 0.000

8. Results
PI in all groups of
KC
F Value P value
PI minimum 16.58 0.000
PI maximum 20.82 0.000
PI average 19.71 0.000

9. Results
Elevation
point
Mean Std.
Dev
P Value
FRONT NM(30) 2.07 1.80 0.000
KC1 (29)
14.55 9.92
BACK NM(30) 4.23 3.74 0.000
KC1 (29) 33.2 21.5
Elevatio
n point
in all
groups
F Value P Value
Front 1.37 0.000
Back 4.39 0.000

10. Results
•
‘D ‘Values
in all
Groups
F Value P
D 47.58 0.000
Df 36.04 0.000
Db 18.60 0.000
‘D ‘
value
Mean Std
.Dev
P value
NM
(30)
1.159 0.636 0.000
KC1
(29)
6.81 2.94

11. Discussion
• In our study, a descending trend for both PA and at the thinnest
location(PT)was noted for all stages and also for distance between PA and
PT. Similar trend in the difference between PA and PT was noted in all
groups except stage 3(KC3).
• PI , Front and back elevation points and Back difference elevation
points(D,Df,Db,Dp,Dt,Dy) showed an increasing trend in all stages, except
Dt and Dy in Stage 3.
• The variation could be due to small sample size in Stage3(KC3=7)
• A statistically significant difference was noted between normals and stage 1
KC for all parameters.
• Kazutaka Kamiya et al4
also noted similar results for PA,PT and elevation
points with Elevation difference measurements improving the diagnostic
accuracy of keratoconus, especially in the early stage of the disease ,
whereas Xian- Li Du et al5
noted better diagnostic value in moderate stage
of KC
• 4
Kazutaka Kamiya,Rie Ishii et al. Evaluation of corneal elevation, pachymetry and keratometry in keratoconic eyes with
respect to the stage of Amsler-Krumeich classification.Br J Ophthalmol 2014 Apr;98(4):459-63
• 5
Xian- Li Du et al. Correlation of basic indicators with stages of keratoconus assessed by Pentacam tomography. Int J
Ophthalmol. 2015; 8(6): 1136–1140

12. Conclusion
• All parameters on Pentacam assessed in the study, pachymetric,
and elevation based, showed good correlation in all stages of
Keratoconus and significant difference than normals.
• All the parameters could be useful to differentiate between normals
and stage 1 of keratoconus