Incidence of non-glaucomatous ocular disease in patients with asymmetric optic disc cupping.

Abstract

To evaluate the incidence of non-glaucomatous ocular disease in patients with asymmetric optic disc cupping. A retrospective case series, including consecutive patients with cup-to-disc ratio (CDR) asymmetry greater than 0.2. All patients underwent a complete neuro-ophthalmological examination, automated perimetry with the Humphrey 24-2 visual fields program. Retinal nerve fibre layer thickness was measured by optical coherence tomography (OCT). The results of neuroimaging, macular OCT and blood tests were recorded as well. Patients were assigned a diagnosis of glaucomatous optic neuropathy (GON) or non-glaucomatous disease (NGD). The main outcome measure was the rate of non-glaucomatous ocular disease. A total of 120 (67 males) patients with a mean age of 71.1 ± 12.5years met the inclusion criteria and were included in this study. The mean asymmetry in CDR between the eyes was 0.3 ± 0.13 (range, 0.2-0.9). Twenty patients (16.6%) had a visual field defect not typical for glaucoma and positive relative afferent pupillary defect was found in 24 patients (20%). Six patients were found to have newly diagnosed non-glaucomatous ocular disease: maculopathy in three patients, retinopathy in one patient and traumatic optic neuropathy in two patients. Patients with NGD were significantly younger than the patients with GON (59.8 ± 23.3 vs. 71.3 ± 11.5years, P = 0.001). Optic disc pallor was found in 4/93 patients with glaucoma compared to 3/6 with newly diagnosed non-glaucomatous disease (4.7% vs. 50.0%, P = 0.03). Asymmetric optic disc cupping can be associated with non-glaucomatous disease and may warrant neuro-ophthalmological evaluation, especially in younger patients or those with optic disc pallor.