EARLY RIGID GAS PERMEABLE CONTACT LENS ASSISTED MODULATION OF CORNEAL COLLAGEN CROSS-LINKING IN KERATOCONUS: A PROSPECTIVE COMPARATIVE STUDY

To evaluate the effect of early rigid gas-permeable (RGP) contact lens use following corneal collagen cross-linking (CXL) on keratometric and refractive outcomes in patients with keratoconus.

This prospective comparative study included 40 eyes of 40 patients with keratoconus treated at a tertiary care center. 

Patients were divided into two groups: CXL-only (n=20) and CXL followed by early RGP lens use (n=20). Accelerated CXL was performed using 9 mW/cm² fluence for 10 minutes. In the RGP group, lens fitting use of contact lens was initiated two weeks postoperatively. Primary outcomes included changes in flat keratometry (K1), steep keratometry (K2), and maximum keratometry (Kmax) at 1 year. Secondary outcomes included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction spherical equivalent (MRSE), corneal densitometry, pachymetry, depth of demarcation line, and higher- and lower-order aberrations.

Both groups demonstrated significant decreases in K1, K2, and Kmax at 1 year, with no significant intergroup differences. In the RGP group, BCVA improved significantly from 0.19 ± 0.16 pre-CXL to 0.03 ± 0.07 logMAR at 1 year (p = 0.02). UCVA improved significantly in the RGP group (p=0.02) but not in controls; however, BSCVA and MRSE changes were similar. Corneal thickness and volume decreased significantly in both groups without intergroup differences. Anterior corneal densitometry showed greater improvement in controls. Higher-order aberrations declined slightly but non-significantly in both groups. RGP lens use post-CXL was associated with good patient compliance and no contact lens-related complications.

Early initiation of RGP lenses after CXL is safe, does not significantly affect corneal remodelling, and provides early visual rehabilitation in keratoconus patients.