ABSTRACT
Background: Glaucoma is a leading cause of irreversible blindness worldwide. Early detection remains challenging, particularly in resource-limited settings where disc-based assessment is subjective. Optical Coherence Tomography (OCT) provides objective structural measurements such as retinal nerve fiber layer (RNFL) thickness and Bruch’s membrane opening (BMO)–minimumrim width (MRW), which may improve diagnostic accuracy.
Aim: To evaluate the relationship between OCT-derived parameters and optic nerve head findings among individuals classified as glaucoma suspects or cases using International Society of Geographical and Epidemiological Ophthalmology (ISGEO) criteria in a Nigerian population.
Methods: This retrospective study included 310 participants screened during the 2024 World Glaucoma Week at a tertiary hospital. Glaucoma and suspects were defined using ISGEO criteria. OCT imaging (Spectralis SD-OCT) was performed in 55 participants (39.9% of suspects/cases). Global and sectoral RNFL thickness and MRW were analyzed using linear mixed-effects models
adjusting for age, sex, and family history.
Results: Of the 310 participants, 138 (44.5%) were classified as glaucoma suspects or cases, including 24 (7.7%) with glaucoma. RNFL thickness did not differ significantly between groups (all p>0.46). In contrast, MRW was significantly thinner in glaucoma cases globally ( = –26.5 m; p = 0.043) and in multiple sectors (p < 0.05). Family history was independently associated
with glaucoma status (adjusted OR = 1.98; p = 0.031).
Conclusion: MRW demonstrated superior discriminatory ability compared to RNFL thickness in differentiating ISGEO-defined glaucoma cases fromsuspects. These findings support the complementary role of MRW in glaucoma assessment where OCT is available.
Keywords: Glaucoma, Optical coherence tomography, Retinal nerve fiber layer, Minimum rim width, ISGEO criteria