Assessment of Choroidal Thickness in Keratoconus Patients Using Optical Coherence Tomography Among Adult Saudi Patients

Purpose: To investigate macular choroidal thickness in keratoconus patients and correlate it with keratoconus severity.

Materials and Methods: Cross sectional case control study, where a total of 24 subjects aged from 18 to 40 years old, were recruited from ophthalmology clinic of a tertiary care hospital. They were divided into two groups: Control group and keratoconus group (who's already diagnosed by cornea specialist according to slit lamp biomicroscopic findings and corneal topography). All subjects underwent full ophthalmological examination including: Visual acuity (VA) using Snellen chart, intraocular pressure IOP measurement using Goldman applanation tonometer, corneal curvature and thickness measurement using Pentacam, and choroidal thickness( ChT) using optical coherence tomography (OCT). 

Results: Our study carried out on 11 normal and 13 Keratoconus patients revealed that there are no statically significant difference in choroidal thickness and macular thickness between control and keratoconus groups, except at temporal 0.75mm, and the choroidal thickness was significantly higher in the keratoconus group.

Conclusion: In conclusion, studying the correlation between keratoconus and choroidal thickness can be used as a predictive marker of altered basement membrane - retinal pigment epithelium interactions affecting the integrity of outer blood retinal barrier causing CSC and CNM which are common KC association. To the best of our knowledge, our research is the first study correlating keratoconus and posterior segments parameters among adult Saudi population. 

Keywords: Choroidal thickness, Keratoconus, Macula, Optical coherence tomography