Comparison of OCT Findings in Compressive Optic Neuropathy and Primary Open Angle Glaucoma

Primary open angle glaucoma (POAG) and compressive optic neuropathy (CON) may present similarly with painless, slowly progressive visual field loss, thinning of the retinal nerve fiber layer (RNFL), and lack of optic disc edema. This study compares RNFL optical coherence tomography (OCT) characteristics in patients with CON versus POAG.

271 Comparison of OCT Findings in Compressive Optic Neuropathy and Primary Open Angle Glaucoma James Davis 1, Alison Gibbons 2, Amanda Henderson 1, Andrew Carey 1 1 Wilmer Eye Institute, Johns Hopkins University School of Medicine, 2 Johns Hopkins University School of Medicine Introduction: Primary open angle glaucoma (POAG) and compressive optic neuropathy (CON) may present similarly with painless, slowly progressive visual field loss, thinning of the retinal nerve fiber layer (RNFL), and lack of optic disc edema. This study compares RNFL optical coherence tomography (OCT) characteristics in patients with CON versus POAG. Methods: An electronic medical record from an academic tertiary care center was queried for ICD-10 diagnosis of POAG, peri-optic mass lesions, or cerebral aneurysm among patients over age 50 years who underwent brain MRI, visual field, and OCT of the optic nerve. Records were manually reviewed to confirm diagnoses of POAG or CON. POAG was defined using United Kingdom Glaucoma Treatment Study (UKGTS) criteria; CON was defined using the UKGTS visual field criteria or intra-eye GC+IPL thickness asymmetry in corresponding sectors, inter-eye asymmetry in GC+IPL or RNFL, or RNFL < 70 microns. Objective OCT measurements were compared between the two groups. Results: Preliminary analysis identified 47 patients with POAG (93 data points) and 28 patients with CON (44 data points). Vertical cup-to-disc ratio (CDR) < 0.77 carried the highest relative risk (RR) for CON (RR 32.5, mean CON = 0.6, mean POAG = 0.8, p< 0.001) followed by RNFL x Rim Area >102 (RR 16.3, mean CON = 90, mean POAG = 58, p< 0.001). Other distinguishing factors included Rim Area >1.14 (RR 7.3, mean = CON 1.2, mean POAG 0.9, p< 0.001) and RNFL x vertical CDR < 68 (RR 7.2, mean CON = 44, mean POAG = 55, p< 0.001). Conclusions: Several objective OCT measures were significantly different in POAG versus CON eyes. As anticipated, less cupping on OCT may suggest a compressive lesion instead of glaucomatous optic neuropathy, signaling clinicians to consider neuroimaging studies. Future directions include creating an evidence-based calculator to help predict risk of CON based on OCT features. References: 1. Dinsdale M, Guajardo-Beroiza JM, Mohamed-Noriega J, Vallabh NA; Optic neuropathies that mimic glaucoma, Community Eye Health, 35, 23-26, 2022. 2. Fortune B, Grzybowski A; Glaucomatous or Non-glaucomatous Optic NeuropathyIt Is a Question?, Am J Ophthalmol, 234, A5-A7, 2022 3. Garway-Heath DF, Lascaratos G, Bunce C, Crabb DP, Russell RA, et al; The United Kingdom Glaucoma Treatment Study: a multicenter, randomized, placebo-controlled clinical trial: design and methodology, Ophthalmology, 120, 68-76, 2013. 4. Yohannan J, Wang J, Brown J, Chauhan BC, Boland MV, et al; Evidencebased Criteria for Assessment of Visual Field Reliability, Ophthalmology, 124, 1612-1620, 2017. 5. Hata M, Miyamoto K, Oishi A, Makiyama Y, Gotoh N, et al; Comparison of optic disc morphology of optic nerve atrophy between compressive optic neuropathy and glaucomatous optic neuropathy, PLoS One, 9, e112403, 2014. Keywords: Optic neuropathy, Diagnostic tests (ERG, VER, OCT, HRT, mfERG, etc), Neuroimaging, Tumors, Perimetry Financial Disclosures: The authors had no disclosures. Grant Support: None. Contact Information: James B. Davis, [e-mail] 2024 Annual Meeting Syllabus | 431