Abstract
Purpose :
To assess natural progression of keratoconus in progressive and stable keratoconus patients using Scheimpflug-based tomography in an age- and gender-matched clinical cohort.
Methods :
This study included Keratoconus patients from both Erasmus MC and the Rotterdam Eye Hospital. All patients had at least three visits with reliable Pentacam (Oculus, Wetzlar, Germany) scans and a minimum of two months between consecutive scans. Patients were stratified into two age- and gender-matched groups: 1) progressive group (patients who underwent cornea cross-linking (CXL) during follow-up), and 2) stable group (CXL not indicated). Only scans before CXL or any other ophthalmic surgeries were used. If both eyes were eligible, only the eye with the highest baseline maximum keratometry (Kmax) was included. Demographic and Pentacam-derived parameters at baseline were compared between groups (Mann–Whitney U test), Pentacam parameters were compared between the first and last visit within each group (Kruskal-Wallis test), and rate of change per year in corneal parameters was compared between groups (Student’s t-test).
Results :
A total of 444 patients with progressive (n=111) and stable (n=333) keratoconus were included. The mean age ±standard deviation was 24.30±6.27 and 30% were women. The median (range) follow-up time, in months, was 15.0 (11.0-26.5) of the progressive group, and 33.0 (19.0-53.0) of the stable group P<0.001. At baseline, Kmax and thinnest pachymetry (TP) were not different between the progressive and the stable group. In the progressive group, significant changes in corneal curvature (Kmax, ARC, PRC), elevation (front and back), and topometric indices (ISV, IHD, IVA, BAD-D) were found between the follow-up and the baseline visits. These changes were especially prominent in the last visit compared to both the first and second visits. The rate of change in these parameters (Table1) was significantly higher in the progressive group than the stable group (P<0.001).
Conclusions :
In this study, distinct progression rates were identified between age- and gender-matched clinically progressive and stable keratoconus patients. When assessing the progression of keratoconus, consistent changes (more than two visits) in corneal curvature, thickness, elevation and topometric indices should be considered.
This is a 2020 ARVO Annual Meeting abstract.