Coats’ disease: treatment with intravitreal bevacizumab and laser photocoagulation

Editor, Coats’ disease is characterized by retinal telangiectasia, macular oedema, exudation and, consequently, exudative retinal detachment. In its advanced stages, it may be complicated by total retinal detachment and glaucoma and may lead to phthisis bulbi (Shields et al. 2001). It usually presents unilaterally in 8–16-year-old males, although it may occur in patients as young as 4 months (Haller 2004). Exudation characterizing Coats’ disease can be attributed to increased vascular permeability caused by telangiectasia and aneurysms in the posterior pole and/or the periphery, facilitating release of vascular endothelial growth factor (VEGF). This growth factor has been shown to cause telangiectasia, microvascular occlusion, microaneurysms, and, consequently, vascular leakage, thus promoting exudation (Sun et al. 2007). Recently, antibodies against VEGF (bevacizumab [Avastin™; Genentech], ranibizumab [Lucentis™; Novartis AG] and pegaptanib [Macugen™; Pfizer, Inc.]) have been employed in managing conditions characterized by exudation, such as age-related macular degeneration (AMD) and diabetic macular oedema (DMO) (Minnella et al. 2007). Corticosteroids have been known to reduce intraocular inflammation, tighten capillary walls and suppress cell proliferation. Intravitreal triamcinolone acetonide has been shown to be useful in increasing visual acuity (VA) in patients with diffuse DMO (Sivaprasad et al. 2006). We describe the management of Coats’ disease in a young adult male, in which laser photocoagulation along with bevacizumab/triamcinolone intravitreal injection were employed. A 17-year-old male was referred with a severe decrease in VA OD occurring over some weeks. Ophthalmic evaluations included non-standardized Snellen VA, and complete ophthalmic and fundus examination. Active neovascularization in the optic disc and/or elsewhere was confirmed with fluorescein angiography (FA). The patient’s VA OD was 20/1000. Fundus examination revealed considerable exudation involving the posterior pole, and macroaneurysms and telangiectases in the temporal periphery (Fig. 1A). Localized telangiectases in the periphery combined with the overall clinical picture was compatible with Coats’ disease diagnosed in adulthood. These findings were confirmed in FA (Fig. 2A). Treatment consisted of 0.05 ml Avastin™ (1.25 mg bevacizumab) (Genentech, San Francisco, California, USA) and 0.05 ml Kenacort™ (2 mg triamcinolone acetonide) (Bristol-Myers, New York, NY, USA) drawn and 0.1 ml of the combined solution injected intravitreally under sterile conditions. Laser photocoagulation was performed once at the beginning of the treatment to obliterate peripheral telangiectases (shown in FA) (Fig. 2B). Fundus photographs and corresponding optical coherence tomography scans of the right eye in a patient with Coats’ disease. (A) At baseline, prior to the first injection of intravitreal bevacizumab. (B) At 1 week after the first injection and peripheral laser ablation of the lesion. (C) At 3.5 months, after two injections of intravitreal bevacizumab. Right eye in a patient with Coats’ disease. (A) Fluorescein angiogram of the temporal periphery with macro-aneurysms. (B) The same area after laser photocoagulation. One week later, VA was 20/400. Clinical examination revealed a considerable decrease in previously observed posterior pole exudation, particularly in the macula (Fig. 1B). Injections of 0.1 ml bevacizumab/triamcinolone were administered at 1.5 months (VA 20/200) and 4 months. Approximately 3.5 months after the initial injection, exudation had regressed markedly in the periphery and the macular area, representing a substantial improvement coupled with considerable VA increase (20/60) (Fig. 1C). Laser photocoagulation has long been considered a treatment of choice for Coats’ disease, especially when extensive and progressing exudation threatens central vision, such as in the case presented here. As photocoagulation causes irreversible retinal damage, potentially increasing vitreoretinal traction, less permanent treatment options would be preferable, particularly in less complicated cases. Coats’ disease has been associated with blood−retinal barrier deficiency and elevated VEGF levels, which suggests that this growth factor may have a role in the pathophysiology of the disease (Sun et al. 2007) and potentially justifies anti-VEGF treatment. In our case, bevacizumab/triamcinolone solution combined with laser photocoagulation produced significant reductions in exudation and oedema coupled with marked VA improvement. Remarkably, there was no exudation recurrence between injection intervals or during the follow-up period. Furthermore, this treatment option probably reduces the need for laser photocoagulation. The observations reported here may support the feasibility of anti-VEGF treatment as an effective supplementary management option for Coats’ disease. Further studies are necessary to establish the exact anti-VEGF dosage for effective Coats’ disease treatment.