Optic nerve head abnormalities in primary open-angle glaucoma and their associations with axial length

PURPOSE: To determine the frequency of peripapillary retinoschisis (PRS), lamina cribrosa defect (LCD), peripapillary intrachoroidal cavitation (PICC), and prelaminar schisis (PLS) in primary open-angle glaucoma (POAG) eyes and investigate their association with axial length (AXL). STUDY DESIGN: Retrospective cross-sectional METHODS: Optical coherence tomography scans of 263 POAG eyes were reviewed for PRS, LCD, PICC, and PLS. The frequency of each optic nerve head (ONH) abnormality was compared between eyes with and without high myopia (HM), defined as AXL > 26 mm. Associations with AXL were assessed using univariable and multivariable logistic regression, adjusting for gender, age, intraocular pressure, visual field mean deviation, circumpapillary retinal nerve fiber layer thickness and Bruch's membrane opening (BMO) area. RESULTS: PRS, LCD, PICC, and PLS were observed in 11.8%, 31.6%, 18.3%, and 55.1% of all POAG eyes, respectively. 77.2% exhibited at least one abnormality, and 31.2% had multiple abnormalities. PRS, LCD, and PICC were more frequent in HM eyes (p = 0.001, 0.016 and <0.001, respectively) and associated with longer AXL in univariable analysis (p < 0.001). Multivariable analysis showed that PRS significantly associated with longer AXL (p < 0.001) and that LCD and PICC significantly associated with larger BMO area (p = 0.009, < 0.001). PLS was more frequent in eyes without HM (p = 0.026) and significantly associated with shorter AXL (p = 0.005). CONCLUSION: ONH abnormality was common in myopic POAG eyes with substantial overlaps. PRS, LCD and PICC were associated with longer AXL and myopic ONH structural change while PLS was associated with shorter AXL. These findings will be a foundation for further studies exploring their functional relevance.