Contrast Sensitivity And Higher Order Aberrations In Patients With Keratoconus After Corneal Collagen Cross- Linking

To evaluate postoperative changes in visual acuity, contrast sensitivity, keratometric parameters, and HOAs in keratoconus patients following accelerated epithelium-off CXL.

Mansoura Ophthalmic Center, Mansoura University, Egypt

This prospective interventional study was held at Mansoura ophthalmic center, Mansoura university, Egypt. This study included 30 keratoconus patients who recieved corneal cross-linking surgery selected from outpatient clinic of Mansoura Ophthalmic Center during the period from May 2023 to May 2024. Visual acuity, contrast sensitivity, keratometric parameters, and HOAs were assessed preoperatively and followed up at 1,3 and 6 months postoperatively.

Contrast sensitivity was decreased non-significantly from 1.14±0.55 to 1.11±0.48  at 1 month post CXL, then improved significantly by 6 months (p<0.001). HOAs, including RMS and spherical aberrations, increased initially from 2.18± to 2.23±0.39 and from 0.64±0.22 to 0.69±0.15 respectively  but decreased significantly to 1.88±0.40 and 0.50±0.14 respectively at 6 months post-operatively, indicating enhanced optical quality. Vertical coma and horizontal coma reduced significantly at the end of follow up period, while trefoil changes were variable. Keratometric indices (K1, K2, Kmax) and astigmatism showed gradual post-operative reduction, while CCT and ARTmax improved significantly by 6 months. 

Accelerated CXL in early keratoconus induces structural and functional alterations and leads to significant improvement in visual acuity, contrast sensitivity, keratometric stability, and HOAs by 6 months postoperatively.