Comparison of optic disc morphology between glaucomatous and non-glaucomatous myopic eyes using swept-source optical coherence tomogaphy (SS-OCT)

Background: The rising global prevalence of myopia is a growing concern for clinicians, as it predisposes patients to severe ocular pathologies including glaucoma. Myopia can be associated with clinical features that resemble glaucomatous damage, which make an accurate glaucoma diagnosis challenging, particularly among patients with normal intraocular pressures. This study aimed to compare the optic disc morphology, macular retinal ganglion cell layer and retinal nerve fiber layer (RNFL) between non-glaucomatous and glaucomatous myopic eyes using swept-source optical coherence tomography (SS-OCT). Methods: 100 participants were recruited which included 50 glaucomatous eyes and 50 non- glaucomatous eyes. All participants underwent standard optometric examination which includes best-corrected visual acuity (BCVA), standard retinoscopy, slit-lamp biomscroscopy, intraocular (IOP) measurement, visual field testing using automated perimetry and fundus examination using SS-OCT. The SS-OCT modalities used for optic nerve head measurements (rim area, disc area, vertical cup-to-disc ratio and cup volume) was 3D Disc 6.0×6.0 mm mode while 3D Macula 7.0×7.0 mm mode was used for macula area measurements. Results: The disc area, rim area, vertical cup- to-disc ratio, cup volume, macular ganglion cell layer and total retinal nerve fibre layer thickness were all found comparable between glaucomatous and non- glaucomatous groups (all P > 0.05). Conclusion: This study found no significant differences in the optic disc parameters and macular ganglion cell layer of glaucomatous and non-glaucomatous myopic eyes.