A novel large diameter rigid gas-permeable corneal contact lens design for keratoconus

Abstract

Purpose

To assess the fitting process and clinical feasibility of a novel large diameter rigid gas-permeable (RGP) corneal contact lens (CL) presenting regular or reverse geometry for managing keratoconus (KC). The lens was designed to rest on the peripheral cornea and vault over the cone, aiming to enhance visual quality, comfort, and corneal physiology.

Methods

32 KC patients across all severity stages, including central, paracentral and peripheral cones enrolled. Lens parameters were customized from corneal measurements obtained via Oculus Pentacam HR tomography, mainly based on sagittal height and accounting for adequate tear film clearance. Visual acuity (VA), contrast sensitivity (CS), ocular complications, and user satisfaction were evaluated at baseline, and at one week and three months of lens wear.

Results

Twenty-four patients (41 eyes) were fitted and completed the 3-month follow-up (median age of 28.5 years, 9 females). A median of 2 trial lenses per eye (interquartile range of 4.5) were needed during the fitting process. Significant improvements in median VA (baseline: 0.32 logMAR; three months: 0.01 logMAR; p = 0.002) and CS (p < 0.001 at all frequencies) were observed compared to baseline values. Ocular complications remained below clinical significance, with superior limbic keratoconjunctivitis showing significant reduction over time (p < 0.001). Patient satisfaction was high, with a median daily lens wear of 9.5 h. Most users (79.2%) reported consistent comfort with their CLs.

Conclusion

The novel large diameter RGP corneal CL demonstrated comparable efficacy to existing RGP CL designs, offering high levels of comfort and improved vision with minimal ocular complications.