Therapeutic effect of faricimab in macular telangiectasia type 1 and Coats’ disease: case series

To report the anatomical and functional outcomes of intravitreal faricimab injection in cases of macular telangiectasia type 1 and Coats’ disease that were refractory to previous treatments. We describe four cases of macular telangiectasia type 1 and Coats’ disease with macular edema, which were treated with intravitreal faricimab injection. Four patients with persistent cystoid macular edema despite prior treatment received intravitreal faricimab injections, and two of them showed anatomical and visual improvement. In case 1, a patient with Coats’ disease achieved improved telangiectatic vessel at macula and visual recovery following eight monthly injections of faricimab, with central macular thickness (CMT) reduced from 645 μm to 217 μm and BCVA improved from 20/30 to 20/25. In case 2, a patient with diabetic retinopathy and suspected macular telangiectasia type 1 showed improvement in CMT (670 μm to 219 μm) and visual acuity (20/63 to 20/40) with resolution of telangiectatic vessel with leakage after four faricimab injections. Case 3 and 4 were chronic and long-standing cases; in case 3, a patient with Coats’ disease demonstrated partial response with reduced macular edema, while in case 4, with a Coats’ disease, showed no response after two faricimab injections. Faricimab may provide therapeutic benefits in cases of macular telangiectasia type 1 and Coats’ diseases unresponsive to previous anti-VEGF agents, potentially due to its dual inhibition of vascular endothelial growth factor-A and angiopoietin-2. However, its efficacy may be limited in patients with chronic phase. Further studies are warranted to assess its role in vascular retinal diseases beyond currently approved indications. What is known: Faricimab is a bispecific monoclonal antibody targeting both VEGF-A and angiopoietin-2 pathways, approved in neovascular age-related macular degeneration, diabetic macular edema, and retinal vein occlusion. What is new: Faricimab treatment reduced macular edema and regressed telangiectatic vessels in selected cases of macular telangiectasia type 1 and Coats’ disease. Its therapeutic efficacy however, may be less pronounced in chronic or long-standing cases. This study demonstrated the anatomical and functional improvement of faricimab in reducing macular edema and regressing telangiectatic vessels in macular telangiectasia type 1 and Coats’ disease refractory to conventional anti-vascular endothelial growth factor or corticosteroid therapy. However, the therapeutic response may be less pronounced in chronic or long-standing cases, likely due to irreversible structural damage of the retina.