Optical coherence tomography in differential diagnosis of optic neuropathy of various genesis

S.I. Zhukova¹, D.Yu. Samsonov¹, T.N. Yurieva^1–3, T.V. Prozorova¹ ¹Irkutsk Branch of the S. Fyodorov Eye Microsurgery Federal State Institution, Irkutsk,&nbsp;&nbsp; Russian Federation ²Irkutsk State Medical Academy of Professional Education — Branch of the Russian&nbsp;&nbsp; Medical Academy of Continuous Professional Education, Irkutsk, Russian Federation ³Irkutsk State Medical University, Irkutsk, Russian Federation <b>Background: </b>although thinning of peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC) revealed by optical coherence tomography (OCT) are nonspecific data, they represent a key link in pathogenesis of optic neuropathy (ON) regardless of etiology. <b>Aim: </b>to identify differences between OCT patterns of RNFL and GCC damages associated with ON of different genesis. <b>Patients and Methods: </b>еxamination data of 58 patients with a suspected or preliminary diagnosed glaucoma who underwent an ophthalmic examination in a glaucoma department were retrospectively analyzed. According to the findings, 2 groups were formed. A Group 1 included 19 patients with an initial stage of primary open-angle glaucoma. 12 patients with altered RNFL and GCC, ineligible for glaucoma ON (GON), were enrolled in a non-glaucoma ON (non-GON) group. As a result of a detailed analysis of complaints, systemic and neurological status, chronic non-arteritic ischemic ON was diagnosed in 5 patients of the Group 2. In 7 patients, ON was associated with a history of optic neuritis with underlying multiple sclerosis (MS). Thus, we are faced with ONs associated with glaucoma, ischemia and MS. Considering a fundamentally different approach to treatment of these diseases and relevance of their differential diagnosis, a comparative analysis of ganglion cell axon topography was carried out in 3 groups in the light of the medical condition (1 — glaucoma-associated lesions, 2 — ischemia-associated lesions, 3 — MS-associated lesions). <b>Results: </b>the most pronounced RNFL alterations were observed in lower and temporal quadrants (GON patients); upper and nasal quadrants (ischemia patients); and in a temporal quadrant (MS patients). Retinal GCC lesions associated with GON and ischemia were asymmetric (superior defects in glaucoma patients vs. inferior defects in ischemia ones). MS-associated macular lesions were symmetrical and outstripped the RNFL alterations. <b>Conclusion:</b> different patterns of peripapillary RNFL and macular GCC damages are caused by pathogenesis of primary neuronal damage. These differences can be used as differential diagnostic criteria for GON and non-GON conditions in routine clinical practice. <b>Keywords</b>: optical coherence tomography, peripapillary retinal nerve fiber layer, macular ganglion cell complex, glaucoma ischemic optic neuropathy, non-arterial ischemic opticopathy, retrobulbar neuritis, multiple sclerosis. <b>For citation:</b> Zhukova S.I., Samsonov D.Yu., Yurieva T.N., Prozorova T.V. Optical coherence tomography in differential diagnosis of optic neuropathy of various genesis. Russian Journal of Clinical Ophthalmology. 2024;24(4):170–176 (in Russ.). DOI: 10.32364/2311-7729-2024-24-4-2