A 58-year-old white woman with diabetes type 2 (5-year duration) taking metformin 1 g/day came for evaluation due to progressive visual loss associated with visual field constriction and bilateral scotomas. Visual acuity was 20/40 bilateral (Snellen chart). Ishihara plates, ocular motility, applanation tonometry, pupillary reflex, and anterior biomicroscopy were normal. Retinal mapping showed light arterial narrowing, optic disc pallor, and focal RPE alterations. FA showed few microaneurysms in the left eye (LE). VF (Goldmann perimeter) showed bilateral and concentric visual field loss. OCT showed thinning of the photoreceptor layer and sparse disruption of the ellipsoid zone. ERG showed an accentuated reduction in photopic and scotopic responses and in implicit time. Serologic investigations (including syphilis, tuberculosis, and toxoplasmosis) were nonreactive. Cardiovascular, hematologic, and neurologic investigations were normal. Thorax tomography showed a tumoral lesion in the right pulmonary lobe. The patient was submitted for lobectomy. Antirecoverin became positive. Treatment was initiated with oral and subtenonian triamcinolone, without response. Systemic immunosuppression was not tolerated. Ozurdex has been injected at 6/6-month intervals (last 2 years), and no more changes were observed in comparative examinations. The patient has remained functionally stable (Figure 1).