Corneal Confocal Analysis after Scleral Lens Wear in Keratoconus Patients: A Pilot Study

Abstract

SIGNIFICANCE: Scleral lenses rely on the scleroconjunctival region without bearing the cornea, which could improve the symptoms and modify the corneal nerve plexus morphology.
PURPOSE : This study aimed to evaluate symptoms and changes in corneal nerve plexus morphology and density of Langerhans cells in keratoconus patients with and without intrastromal corneal ring before and after scleral lens wear.
METHODS : Sixteen scleral lens wearers with keratoconus were recruited for this short-term experimental pilot study. Subjects were divided into two groups: keratoconus group and intrastromal corneal ring segment group. All subjects were examined in two visits: baseline (before scleral lens wear) and after 6 months of scleral lens wear, after lens removal. The Schirmer I test, the Ocular Surface Disease Index, tear breakup time, and in vivo confocal microscopy were evaluated.
RESULTS: The mean age was 42.33 ± 11.27 years. A significant decrease in tear breakup time was found in the total group (P = .01, Wilcoxon) compared with baseline. Ocular Surface Disease Index score had decreased after 6 months of scleral lens wear in the keratoconus with intrastromal corneal ring segment subgroup (P = .03, Wilcoxon) and in the total group (P = .001, Wilcoxon). No statistical changes in nerve density, tortuosity, and ramification were found for either the total group or the subgroup. However, the mean nerve length was higher in all groups, especially in the keratoconus subgroup (P = .03, Wilcoxon) after 6 months of scleral lens wear. Regarding optical density, the total group showed a significant increase after 6 months of wearing (P = .02, Wilcoxon). Finally, Langerhans cell density was not statistically different in any group.
CONCLUSIONS: These results suggest that scleral lens wearing improves the symptoms and increased the mean length nerves after 6 months of wear use in keratoconus patients.