Objective and Subjective Evaluation of Clinical Performance of Scleral Lens with Varying Limbal Clearance in Keratoconus.

ABSTRACT

SIGNIFICANCE: This study evaluates how limbal clearance (LC) may impact the clinical performance of scleral lenses based on subjective response on comfort and ocular responses. Limbal zone designs in scleral lenses might affect the integrity of the limbal epithelial tissue as a result of a combined hypoxic and compression-related etiology. PURPOSE: This study aimed to investigate the clinical performance and ocular and subjective responses to the wear of scleral lenses having varying LC. METHODS: Lenses with varying LC with a difference of 50 µm were fitted on and compared among keratoconic participants. The lenses were worn during a 2-week period. Visual analog scales concerning subjective comfort were completed. Ocular surface findings including hyperemia, limbal staining, and corneal swelling were compared. RESULTS: Participants reported greater comfort achieved with high LC. No difference in limbal and bulbar hyperemia was found (P > .05). Corneal response to scleral lens wear with both low and high LCs seems to result in similar perilimbal staining and negative corneal staining. An increase in corneal pachymetric values was noted at the central and peripheral cornea, with no difference between low- and high-LC lenses (all, P < .05). Quadrant-specific analysis indicated that all meridians at both 6 and 8 mm were increased for the low-LC lenses (all, P < .05) and only the temporal region for the high-LC lenses (P = .02). CONCLUSIONS: Limbal clearance may play an important role in subjective performance in scleral lenses but does not impact the degree of hyperemia in either the limbal or bulbar region. Although low LC might result in more compression-related changes to ocular surface, high LC is associated with greater comfort and greater edematous changes. Limbal zone designs in scleral lenses might affect the integrity of the limbal epithelial tissue as a result of a combined hypoxic and compression-related etiology.