ASSESSMENT OF POSTOPERATIVE EFFECT OF CORNEAL CROSS-LINKING ON KERATOCONUS USING THE ABCD GRADING SYSTEM

Abstract

Objective: To monitor changes in parameters of ABCD (A:Anterior radius of curvature of cornea, B:Posterior radius of curvature of cornea, C:Corneal thickness, D:Distant visual acuity) grading system during one-year follow up after corneal cross-linking.

Study Design: Prospective Cohort Study

Place and Duration of Study: Armed Forces Institute of Ophthalmology, Rawalpindi Pakistan. One year duration from January 2023- January 2024.

Methodology: A total of 270 patients having keratoconus were enrolled after taking informed consent. Patients underwent cross-linking and were examined at baseline visit and followed up at 3,6 and 12 months after CXL (Corneal Collagen Cross-linking). All patients had standard CXL protocol with visual acuity in log Mars and Scheimpflug tomography carried out at each visit. ABCD grading was monitored throughout.

Results: In 270 patients with mean age of 23.8 ± 4.37 years, Parameter A (Anterior radius of curvature of cornea) increased in first three months from 6.28 (median) to 6.31 however by 12 months it dropped slightly to 6.30. Parameter B (Posterior radius of curvature of cornea) and C (Corneal thickness) showed progression (median increased from 4.6 to 4.8 and 417 to 430 respectively in 03 months) while parameter D (Distant visual acuity) initially declined (0.2 median to 0.1) but became stable later to pre-CXL value of 0.2.