Combined intravitreal bevacizumab and argon laser treatment for Coats’ disease

Editor, Coats’ disease is characterized by the formation of telangiectatic and aneurysmal changes of the retinal vessels and is associated with a large amount of yellowish subretinal exudates (Harris 1970). Previous treatment options have included cryotherapy and laser photocoagulation of telangiectasia and aneurysms, surgery for exudative retinal detachment and enucleation (reserved for those with intractable rubeotic glaucoma) (Kiratli & Eldem 1998). We report a case of Coats’ disease that was treated successfully with a combination of bevacizumab and laser photocoagulation. A 15-year-old Chinese boy presented with a 2-year history of progressive blurring of vision in his right eye. There was no significant past ocular history. On examination, Snellen visual acuities were 6/60 in his left eye (OD) and 6/6 in his right eye (OS). Fundoscopy revealed extensive panretinal exudation with telangiectacic vessels (Fig. 1). Fluorescein angiography showed extensive areas of non-perfusion with characteristic light-bulb aneurysms (Fig. 2). A clinical diagnosis of Coats’ disease was made. Fundal photograph showing extensive subretinal fluid and exudation. Fluorescein angiography showing characteristic light-bulb aneurysms. The patient elected to proceed with intravitreal bevacizumab treatment after informed consent to the off-label use of this drug was gained from both the boy and his parents. Both the ocular (anterior-segment injury, cataract formation, retinal detachment, retinal pigment epithelial tear and acute vision loss) and systemic (cerebral infarction, hypertension and facial skin redness) risks of intravitreal bevacizumab were discussed (Shima et al. 2008). The patient received a single injection OD. Significant reduction in subretinal fluid and exudation was noted; therefore, focal argon laser photocoagulation to the telangiectactic vessels and areas of non-perfusion followed 2 weeks later. Further improvement in retinal exudation was noted and the patient remained stable at 1-year follow up, with visual acuities 6/45 OD and 6/6 OS (Fig. 3). Fundal photograph showing reduction in subretinal fluid and exudation at 1-year follow up. Bevacizumab is a full-length humanized recombinant antibody against vascular endothelial growth factor (VEGF). Although it is approved for the treatment of colorectal, lung and breast cancer, there have been numerous reports of its safety and efficacy in the off-label treatment of choroidal neovascularisation (CNV) and other ischaemic-proliferative retinopathies such as diabetic retinal neovascularization (Avery et al. 2006; Kernt et al. 2007; Fang et al. 2008; Tonello et al. 2008). The intravitreal injection of pegaptanib sodium (another anti-VEGF molecule) has been shown to reduce VEGF levels in a patient with Coats’ disease (Sun et al. 2007). Only four other cases documenting the use of bevacizumab in the treatment of Coats’ disease have been described (Alvarez-Rivera et al. 2008; Cakir et al. 2008; Venkatesh et al. 2008). However, our case describes the benefits of using intravitreal anti-VEGF in combination with subsequent laser photocoagulation. This strategy allows both the reduction of the subretinal fluid and exudation with the anti-VEGF prior to any subsequent laser, thereby potentially improving its efficacy. The optimal time period between intravitreal injection and laser treatment is unclear, but we feel that this should be judged clinically on an individual basis by the response to anti-VEGF treatment. In summary, we would like to highlight to clinicians the option of treatment with a combination of intravitreal bevacizumab followed by subsequent argon laser in the management of Coats’ disease.