Retinal Nerve Fiber Layer and Ganglion Cell Complex Thickness Analysis in Treatment – Naive Glaucoma Patients

Aim: To evaluate RNFL (Retinal Nerve Fiber Layer) and GCC (Ganglion Cell Complex) thickness, using SD-OCT in treatment-naive patients of primary open-angle glaucoma (POAG), primary angle-closure glaucoma (PACG) and normal-tension glaucoma (NTG) and to compare these findings with healthy controls. Material and Methods: The study included 150 eyes of 75 glaucoma patients (25 each of POAG, PACG, NTG) and 200 eyes of 100 controls. In this cross-sectional observational study, patients meeting the inclusion criteria underwent comprehensive ophthalmic examinations, including best-corrected visual acuity, intraocular pressure (IOP) by Goldmann applanation tonometry (GAT), gonioscopy to differentiate between open and closed angle and visual field analysis (VFA). GCC-IPL and RNFL thickness were measured using SD-OCT. Results: Significant thinning of RNFL was noted in all glaucoma subtypes, especially in inferior and superior quadrants (p < 0.0001). GCC also showed thinning, notably in inferior and superior sectors, although the average GCC reduction was not statistically significant overall (p = 0.0611). Visual field mean deviation (MD) was worse in glaucoma eyes (-2.69 dB) compared to controls (-0.89 dB, p = 0.041), reflecting functional loss. POAG and NTG showed more prominent GCC, RNFL, VF correlations than PACG. Conclusion: The study highlights that RNFL remains a robust early biomarker of glaucomatous damage, while inferior and superior GCC thickness may enhance sensitivity in detecting early structural changes, especially in treatment-naive patients. Combining RNFL and GCC analysis with VFA strengthens early diagnosis and subtype differentiation in treatment-naive primary glaucoma.