Changes in the corneal thickness and limbus after 1 year of scleral contact lens use

Purpose To assess the physiological changes in the cornea over time in patients with irregular cornea fitted with Rose K2 XL gas-permeable scleral contact lenses. Methods Prospective study of 16 eyes of patients who did not tolerate gas-permeable corneal contact lenses and were fitted with Rose K2 XL scleral lenses. We assessed the central vault and the corneal thickness centrally and at peripheral regions (2 to 5 mm annulus). All these measures were obtained by anterior segment optical coherence tomography. The measurements were taken immediately after fitting the lenses and 1, 6 and 12 months later. Prior to the study and at 1 year, we performed an objective test for diagnosing limbal stem cell deficiency (Limbokit). Results The mean vault was 201.7 ± 82.3 µm 20 min after fitting the contact lens; 189.4 ± 94.0 µm at 1 month; 165.1 ± 75.9 µm at 6 months and 142.1 ± 76.8 µm at 1 year, the values at 6 and 12 months being significantly different to baseline. After 1 year, the central corneal thickness had increased by 2.3% (IQR = 5.6), but the changes were only significant for the superior thickness. There is no limbal stem cell deficiency after 1 year of scleral contact lens use. Conclusions After use of Rose K2 XL scleral contact lenses, the corneal physiology of patients with an irregular cornea remains unchanged, as assessed by corneal thickness measurements and the Limbokit test. In all cases, however, the vault decreased over time.