Effect of Corneal vs Scleral Rigid Gas Permeable (RGP) Lenses on corneal curvature and thickness in patients of Keratoconus

Abstract

Objective: To investigate the changes in corneal curvature and thickness in patients of Keratoconus, wearing Rose k2 corneal and XL (scleral lenses) from last three months.

Methodology: Interventional study was conducted at The Keratoconus Clinic, Eye 2 Eye Optometrists Lahore. A total of 44 eyes were fitted with rose k2 corneal (15) and rose k2 XL (29) lenses respectively. Curvature and thickness were measured by keratometry and pentacam scan at two time points: first on lens dispensing visit and three month later after some hours of lens wear. Variation in curvature and thickness were measured.

Results: The study comprised twenty-three people with keratoconus (44 eyes). They were all young, healthy adults between the ages of 18 and 45. The 23 subjects included 14 males (27 eyes) and nine females (17 eyes). Eight patients (15 eyes) were using Rose K2 corneal design, whereas fifteen patients were using Rose K2 XL(scleral) lenses (29 eyes). The average optical Pachymetry was ±2.7 percent higher (p<0.001) three months following lens removal than at the dispensing visit. Following contact lens wear, the average K1 (flat) was 0.29 diopters (D) lower (p=0.037), whereas the average K2 (steep) was 0.70 diopters (D) lower (p<0.001).

Conclusions: This study concluded that rose k2 corneal and XL lenses caused flattening of corneal curvature and increased the pachymetry values as well but the duration of this change is unknown.

Key words: Keratoconus, Corneal RGP, Scleral Lenses, corneal pachymetry and curvature