Role of bruch's membrane opening area: a clinical indicator of the progression of macular defects in high myopia.

OBJECTIVE: To investigate the relationship between the morphology of the optic nerve head (ONH) region and macular Bruch’s membrane (BM) defects in patients with high myopia. METHODS: This study included 77 individuals (77 eyes) who met the inclusion and exclusion criteria for retrospective analysis. According to the macular lesion pattern, the eyes were divided into group A (tessellated retina), group B (diffuse atrophy), and group C (macular BM defects). Demographic and ocular parameters, including age, axial length, ONH area, Bruch’s membrane opening (BMO) area, BMO/ONH area ratio, and posterior scleral morphology(PSM), were compared among the groups. RESULTS: The mean ages of patients in Groups A, B, and C were 40.35 ± 14.87 years, 45.41 ± 12.82 years, and 48.58 ± 14.12 years, respectively, with no statistically significant difference among the groups (F = 2.546, P = 0.085). The axial lengths in Groups A, B, and C were 29.12 ± 1.70 mm, 30.48 ± 1.77 mm, and 30.72 ± 1.62 mm, respectively. The ONH areas were 2.45 ± 0.62 mm², 2.01 ± 0.77 mm², and 2.82 ± 0.73 mm², respectively. The BMO areas were 6.18 ± 3.27 mm², 8.40 ± 8.36 mm², and 14.08 ± 6.63 mm², with 95% confidence intervals (CIs) of 5.04–7.32 mm², 4.10–12.70 mm², and 11.40–16.75 mm², respectively. The BMO/ONH ratios were 2.55 ± 1.29, 3.89 ± 2.82, and 5.17 ± 2.44, respectively. Significant differences among the three groups were observed in axial length (F = 7.646, P = 0.001), ONH area (F = 7.174, P < 0.001), BMO area (F = 13.514, P < 0.001), and BMO/ONH ratio (F = 11.329, P = 0.001). However, posterior scleral morphology did not differ significantly among the groups (χ² = 3.2, P = 0.783). Multivariate analysis revealed that the Bruch’s membrane opening (BMO) area is the only factor significantly associated with macular lesions (AOR = 1.16, 95% CI: 1.04–1.32). ROC analysis showed that a BMO area of 9.04 mm² (AUC = 0.850, P < 0.001) was the optimal threshold for predicting macular BM defects. CONCLUSIONS: BMO enlargement is associated with macular BM defects in highly myopic eyes. A BMO area greater than 9.04 mm² may serve as a predictor of macular BM defects.