Evaluation of the effect of patching therapy on dry eye tests and tear film osmolarity in children with amblyopia.

BACKGROUND: To compare dry eye tests, meibography, and tear film osmolarity between eyes with and without patching therapy in amblyopic children and evaluate the effects of patching duration on these parameters. METHODS: Cooperative children aged between 4 and 12 years, with no history of ocular surgical intervention or ocular surface disease, who had been on patch therapy for at least 3 months due to monocular amblyopia, were included. Tear osmolarity was measured first, before any ocular surface manipulation, using the TearLab® Osmolarity System (TearLab Corporation, San Diego, CA, USA). This was followed by tear film break-up time, fluorescein ocular surface staining, Schirmer 1 testing, and upper and lower eyelid meibography. Patients were divided into two groups based on daily patching duration (Group 1: 2-6 h/day, n = 21; Group 2: more than 6 h/day, n = 28). The findings were evaluated comparatively. RESULTS: A total of 98 eyes from 49 patients (22 females, 27 males), with a median age of 7 years (IQR: 5-8; range: 4-12), were included. There was no significant difference in age or gender between the two groups (p = 0.660, p = 0.089 respectively). T-BUT values were similar between the patched and unpatched amblyopic eyes [12 (10-13) vs. 12 (10-14) s; p = 0.129]. Oxford fluorescein staining also showed no significant between-eye difference (p = 1.000). Although osmolarity was higher in the patched eyes, this difference was not statistically significant (p = 0.162). There was no difference in median Schirmer values (p = 0.091). Although median osmolarity was higher and Schirmer 1 was lower in Group 2, these differences were not statistically significant (p = 0.396, p = 0.633 respectively). Upper and lower eyelid meibography results were categorized based on the presence or absence of any deterioration (Grade 0: No deterioration; Grades 1-3: Any deterioration). No significant differences were found in upper or lower eyelid meibography findings between the patched and unpatched amblyopic eyes (p = 1.000 and p = 0.210, respectively), or between Group 1 and Group 2 (p = 0.740 and p = 0.737, respectively). CONCLUSION: Although patching is considered the gold standard for managing amblyopia, its effects on ocular surface homeostasis remain unclear. In this sample, no statistically significant differences were observed in dry eye tests, tear osmolarity, or meibography findings, and no measurable adverse effect on ocular surface parameters was demonstrated. Daily patching duration was also not significantly associated with these parameters. Larger prospective studies are needed to evaluate potential long-term effects.