Study futility based on the interim analysis

Coats disease is a predominantly unilateral progressive retinal vascular disease, characterized by retinal telangiectasias with intra- or subretinal exudate deposits, which can lead to retinal detachment and one-sided blindness. Several treatment modalities are available and the choice of one of them depends on the stage of the disease and the habits of each center (laser photocoagulation, cryotherapy ...). VEGF (Vascular Endothelial Growth Factor) was found to be significantly elevated in the aqueous humor and subretinal fluid of patients with Coats disease. Several studies have shown the potential efficacy of intra-vitreous injections of anti-VEGF. But the results on their effectiveness have been evaluated only on small series of patients. Most published studies have analyzed their efficacy combined with another treatment, mainly laser photocoagulation. The true efficacy of anti-VEGF therapy as initial therapy, and then combined in Coats disease remains unknown. Currently, several centers are initiating first-line anti-VEGF injections, although no rigorous evaluation of this therapeutic strategy has been conducted.

The identification of the best treatment regimen will allow in the future the reduction of laser reprocessing and will ensure a better functional benefit in the affected patients.

Inclusion Criteria:

• Coats disease confirmed by fundus examination and fluorescein angiography
• Stage 2 or 3 at the fundus (Shields classification)
• Naive to any eye treatment on the eye affected by Coats disease

Exclusion Criteria:

• Other ocular pathology on the eye affected by Coats' disease
• Bilateral forms of the disease
• History of hypersensitivity to bevacizumab
• History of hypersensitivity to products of Chinese hamster ovary cells or other recombinant human or humanized antibodies
• Allergic reaction in a previous fluorescein retinal angiogram
• Pregnancy or breastfeeding
• Active or suspected periocular infection
• Contraindication to treatments used for general anesthesia and morphine derivatives
• Cardiovascular, haemorrhagic and gastrointestinal risks
• Premature baby who has not reached the correct age of 37 weeks