Bilateral Corneal Sensory and Nerve Structural Alterations in Unilateral Scleritis

PURPOSE: The objective of this study was to explore the corneal sensitivity and corneal structure of both eyes in patients with unilateral scleritis. METHODS: This was a cross-sectional case series. We enrolled patients with unilateral scleritis at the Eye Hospital of Wenzhou Medical University between April 2024 and December 2025. Patients with corneal involvement (staining ≥5) were excluded. The corneal sensation of both eyes was examined using a noncontact corneal aesthesiometer and a Cochet-Bonnet aesthesiometer. Then, the corneal structure was examined by in vivo confocal microscopy, and the corneal nerve morphology parameters were calculated using ACCMetrics software. RESULTS: Twenty-four patients (24 affected eyes and their 24 contralateral unaffected eyes) were enrolled, and 24 eyes of 24 age-matched normal volunteers were included as the control group. No significant difference in corneal nerve sensitivity was observed among affected eyes, unaffected eyes, and the control group when measured using the Cochet-Bonnet aesthesiometer, while it was significantly increased compared with unaffected contralateral eyes when measured using the noncontact corneal aesthesiometer (P < 0.001). In addition, we found a significant decrease in corneal nerve parameters in the affected eyes compared with the control group: corneal nerve fiber length, corneal nerve fiber density, corneal nerve branch density, CFracDim (both P < 0.001), corneal total branch density (P = 0.003), and corneal nerve fiber area (P = 0.017); these were lower than those in the unaffected eyes. Moreover, the presence, total area, and perimeter of microneuroma were higher in affected eyes compared with controls (P = 0.003, <0.001, and <0.001, respectively). CONCLUSIONS: Our study demonstrated that hypersensitive state is accompanied by structural nerve degeneration and increased microneuroma formation in the affected eyes in patients with scleritis.