Fig. 26.12 Color photograph of talc retinopathy. Characteristic perifoveal yellow-white intra-arterial glistening crystals

Fig. 26.13 Color photograph of a nonischemic central retinal vein occlusion (CRVO) in a 40-year-old hypertensive female on oral contraceptives. Upon stopping the oral contraceptives, the CRVO resolved without treatment

were more common with older medications, which contained higher concentrations of synthetic hormones [62, 63].

Interferon

The antivirals interferon alpha-2a (Roche Pharmaceuticals, Nutley, NY) and alpha-2b (Schering Corporation, Kenilworth, NJ) are used to treat chronic hepatitis and various malignancies. These agents are associated with a generally mild retinal vascular toxicity consisting of normal vision, cotton-wool spots, and intraretinal

hemorrhages [64]. Visual loss may occur secondary to retinal vascular occlusion [65], CME [66], or NAION [67] (Fig. 26.14a, b). Systemic vascular disease, such as diabetes mellitus, increases the risk of interferon-associated retinopathy [68]. Successful treatment of retinopathy by lowering the blood pressure, without discontinuing the medication, has been recently reported [69].

Toxicity with Maculopathy

Niacin

Niacin (nicotinic acid, vitamin B3) is used to treat hyperlipidemia and hypertriglyceridemia. It causes a characteristic that resembles CME clinically and by OCT, but lacks fluorescein leakage on angiography [70, 71]. This pseudo-CME may be caused by intracellular fluid accumulation, as opposed to true edema, which is in the extracellular space [72] (Fig. 26.15).

Sympathomimetics

Intravenous sympathomimetics, including epinephrine, may be associated with a clinical picture similar to idiopathic acute macular neuroretinopathy [73, 74]. Visual loss or paracentral scotomas may occur, and reddish-brown wedge-shaped lesions may develop in the outer retina (Fig. 26.16). Toxicity may occur even with normal blood pressure [75].

Toxicity with Retinal Folds

Sulfanilamide-Like Medications

Several related medications may be associated with a syndrome including ciliary body swelling, choroidal effusion, and anterior displacement of the lens-iris diaphragm. Anterior segment complications include nonpupillary block angle closure, and posterior segment complications include induced myopia and retinal folds. The fluorescein angiogram shows no vascular leakage, indicating

Fig. 26.14 (a) Color photograph and FA of a patient on interferon for treatment of hepatitis C, showing multiple cotton-wool spots and microangiopathy, and the SD-OCT documents mild cystoid macular edema. (b) Once the

interferon was discontinued, 1 week later, the SD-OCT documents resolution of the CME (Images courtesy of Joseph Maguire, M.D., Philadelphia, PA)