Alterations in contact lens fitting parameters following cross-linking in keratoconus patients of Indian ethnicity.

BACKGROUND: Most studies have either excluded patients using contact lens or not taken their effect while analyzing post-collagen cross-linkage (CXL) changes. This study aims to study impact of CXL on lens fit in both quantitative and qualitative manner. OBJECTIVE: To evaluate changes in CL fit post-CXL and to correlate these changes with alterations in corneal topographic parameters. STUDY DESIGN: Prospective intervention study on 20 keratoconic eyes of 14 patients (age > 18 years), with mean follow-up of 6 months. METHODS: Preoperative evaluation included UCVA, BCVA, corneal topography, AS-OCT and contact lens fit. Patients were evaluated at 2 weeks, 1, 3, 4 and 6 months post-CXL; contact lens trial with standard rigid gas permeable (RGP) lens performed at 3 and 6 months. MAIN OUTCOME MEASURE: Changes in objective and subjective parameters of lens fit. RESULTS: Over 6-month follow-up post-CXL, improvement in visual acuity by one Snellen line, both UCVA and BCVA, and decrease in flat/mean/apical K by 0.8 D, 0.8 D and 1.3 D, respectively, resulted in significant improvement in RGPCL fit. Almost 20% increase in near-ideal fit, 100% acceptable fit, 65% improved subjective comfort with 8 h/day increase in duration of comfortable CL wear were observed. CONCLUSION: Despite no statistically significant change in objective parameters of lens fit, a tendency for flatter lens fit along with contact lens induced further flattening of the ectatic cornea which resulted in marked improvement in both objective and subjective contact lens fit.