Evaluations of Corneas in Eyes with Isolated Iris Coloboma

Abstract

Purpose: We aimed to evaluate the differences in the corneas of eyes with isolated iris coloboma.

Methods: This study was designed as a prospective study. Among patients who applied to our hospital within the last 3-year period, those with isolated iris coloboma in one eye and a completely normal contralateral eye were included in the study. In addition to a complete ophthalmologic examination, all patients were scanned by Pentacam Scheimpflug camera in the dark, and a corneal endothelium cell count was taken using a Topcon Specular Microscope. Data entered using SPSS software were then evaluated by paired t-test; p < 0.05 value was considered statistically significant.

Results: Nine patients, seven men and two women, with a mean age of 35.77 ± 22.50 (range 8-60) years, were included in the study. In comparison to normal eyes, the colobomatous eyes were statistically found to have lower keratometry values in diopters (43.82 ± 2.17, 44.46 ± 1.86; p = 0.040), a greater negative asphericity (Q value) (-0.38 ± 0.07, -0.22 ± 0.20; p = 0.042), increased corneal thickness (569.78 ± 25.42, 537.33 ± 27.36; p < 0.001), decreased anterior chamber depth (2.50 ± 0.32, 2.81 ± 0.50; p = 0.005), a shallower angle (30.51 ± 10.68, 35.29 ± 9.99; p = 0.057), higher best-fit sphere (BFS) values of the anterior and posterior corneal surfaces (7.88 ± 0.39, 7.67 ± 0.37; p = 0.001; 6.40 ± 0.26, 6.23 ± 0.19; p = 0.006), larger pupil diameter (3.48 ± 0.49, 2.80 ± 0.34; p = 0.001), smaller horizontal corneal diameter (HCD) (11.06 ± 0.42; 11.26 ± 0.45; p = 0.009), and higher value of endothelial cell density (ECD) (3161 ± 431; 2923 ± 590; p = 0.031).

Conclusion: We have determined that a number of factors such as keratometry values, particularly of the corneal endothelium, are different from those of normal eyes. These differences should be taken into account in the follow-up and treatment of eyes with iris coloboma.

Keywords: Coloboma; cornea; iris.