appearance and progression: (1) isolated focal exudates;

(2) massive elevated exudation; (3) partial retinal detachment; (4) total retinal detachment; (5) secondary complications such as uveitis, glaucoma, or cataract. In a modification of this scheme, Sigelman designated retinal telangiectasis as the initial stage [16]. Recently, Shields et al. proposed a similar classification that may have useful application to clinical prognosis. In their system, Coats’ disease is classified as follows: (1) telangiectasias only; (2) telangiectasias and exudation; (3) exudative retinal detachment; (4) total detachment with secondary glaucoma; (5) advanced end-stage disease [17].

10.3  Clinical Aspects

10.3.1  Demographics

Recent clinical series have confirmed the epidemiologic and clinical features originally noted by Coats. Cases may present as early as the first month [18] and as late as the eighth decade [14] of life, but approx­ imately two-thirds present before 10 years of age [15, 19]. Younger patients appear to be afflicted more rapidly and with more severe progression. In Haik’s series of 75 patients with advanced disease, 30 (40%) presented before 2 years of age [20]. At all ages, the disease is usually unilateral, and, if bilateral, shows asynchronous progression [10, 21–23]. Seventy percent to 90% of affected children are boys. No racial or ethnic predilection has been shown.

The most common signs of disease are strabismus, leukocoria, and visual impairment detected on routine

a

Fig. 10.1  Peripheral fundus photograph and corresponding fluorescein angiogram of a 4-year-old boy with Coats’ disease. (a) There is extensive intraretinal and subretinal exudation. (b) Angiography reveals characteristic peripheral telangiectasias (“light bulbs”) and large areas of retinal nonperfusion

vision screening. One child presented with turbid yellow fluid filling the anterior chamber [24]. As many as 25% of patients may be asymptomatic and are diagnosed during routine ophthalmic examination [25].

10.3.2  Ocular Findings

The hallmark funduscopic findings in Coats’ disease are vascular telangiectasias and massive subretinal and intraretinal exudates (Fig. 10.1). Affected vessels ­display an irregular caliber, focal telangiectasias, aneurysmal dilatations (“light bulbs”), and sheathing by yellow cholesterol deposits. Microaneurysms may occur in all parts of the vascular bed but most commonly arise from capillaries [6]. In the series of Henkind and Morgan [26], vascular abnormalities, though not always apparent clinically, were found histologically in all cases.

The earliest changes involve the equatorial and peripheral retina, with the temporal quadrants and the sector temporal to the fovea most commonly involved [19, 27]. The posterior pole is involved less frequently than the periphery [6, 19, 20, 28]. In a series of 112 eyes, Spitznas et al. found lipid deposits in the central retina in fewer than 50%, with concomitant vascular changes in only 17% [6]. Shields et al. observed retinal telangiectasias restricted to the macula in only 1% [18].

The macula may become involved directly, by exudation from macular telangiectasias (Figs. 10.2 and 10.3) [4, 29], or indirectly by accumulation of exudate from peripheral retinal telangiectasias (Fig. 10.4). The macular exudate is yellow and occurs in continuous broad sheets that may from subretinal mounds [10, 16]. Macular edema, exudative macular detachment, and

b