Influence of scleral lens removal and reapplication on fluid reservoir thickness and visual quality after 5 h of lens wear.

Purpose: To assess changes in fluid reservoir (FR) thickness and optical quality following the removal and reapplication of a scleral lens worn for 5 h in participants with regular and irregular corneas.

Methods: Two groups with 10 patients were recruited: IC Group-Irregular Cornea; RC Group-Regular Cornea. Both groups were fitted with a diagnostic 16.4 mm scleral lens (hexafocon A). FR thickness was measured with optical coherence tomography (MOCEAN 4000, MOPTIM, Shenzhen Slton Technology Co. Ltd., China l), high and low contrast visual acuity was measured with ETDRS, whole eye aberrometry was assessed with IRx3 Wavefront Aberrometer (ImaginEyes, Orsay, France) for a 5 mm pupil diameter, and the light disturbance under dim light conditions was assessed with Light Distortion Analyzer (LDA, Binarytarget, Portugal). Measurements were taken at 10 min and after 5 h lens wear, as well as following lens removal and reapplication.

Results: Following lens removal and reapplication, FR thickness significantly increased in RC Group (294.3 ± 137.5 to 337.2 ± 141.4 µm, p = 0.005), and in IC Group (311.5 ± 150.3 to 339.5 ± 150.7 µm, p = 0.005, Wilcoxon). Although minor visual fluctuations of 2 letters were found in high and low contrast visual acuity, no statistically significant differences were observed after lens reapplication. Regarding the size and irregularity of light distortion, no statistically significant differences were observed in either group. The aberrometry results demonstrated significant changes, with an increase in comatic vertical aberrations (p = 0.037, Wilcoxon), observed exclusively in IC Group after lens removal and reapplication.

Conclusion: Practitioners should be aware that removing and reapplying a scleral lens with fresh saline solution will increase the FR thickness. However, this increase may not have a significant or clinically meaningful impact on visual acuity, light disturbance size or optical quality as measured by aberrometry.