Longitudinal corneal tomographical changes in eyes of patients with unilateral and bilateral non-progressive keratoconus.

AIM: To evaluate the tomographic indices changes in keratoconic eyes which were classified as unilateral and bilateral non-progressive keratoconus according to the definition of Global Consensus on keratoconus and ectatic disease.

METHODS: Fifty non-progressive fellow eyes of 50 keratoconus patients who underwent corneal cross-linking treatment for the other progressive eyes (group 1), 50 eyes of 50 keratoconus patients who were followed up as bilateral non-progressive keratoconus (group 2), and 50 eyes of 50 control subjects (group 3) were included in this retrospective study. Topographic, topometric, and Belin-Ambrósio Enhanced Ectasia Display-III indices were recorded at baseline and after six months.

RESULTS: Groups were similar in terms of age and gender. The changes in topographic parameters and topometric indices were similar among the three groups (p > 0.05 for all values). The maximum pachymetric progression index (PPImax ), maximum Ambrósio relational thickness (ARTmax ), and final D significantly increased at sixth-months in group 1 (p < 0.001, p = 0.004, and p = 0.02 respectively) but did not change in groups 2 and 3 (p > 0.05 for all values). ARTmax , PPImax , and final D value changes indicated a statistically significant difference among the groups using the one-way ANOVA test (p = 0.03, p = 0.007, and p = 0.03 respectively). The Bonferroni posttest revealed that these values increased at a higher rate in group 1 than in group 2 (p = 0.03, p = 0.01, and p = 0.04 respectively) and group 3 (p = 0.04, p = 0.03, and p = 0.04, respectively).

CONCLUSIONS: Fellow eyes of keratoconus patients who have underwent CXL for their progressive eyes may be more prone to progress than the patients who have no progression in both eyes. Screening unilateral non-progressive patients more closely than those with bilateral non-progressive patients and evaluating the changes in final D, ARTmax , and PPImax values may be helpful in the follow up of non-progressive keratoconus.