AIMS Type 2 (perifoveal) telangiectasia often is refractory to treatment, because focal targets such as aneurysms are not detected by fluorescein angiography (FA) in these eyes. The authors evaluated the efficacy of indocyanine green angiography (IA)-guided laser photocoagulation and sub-Tenon's capsule injection of triamcinolone acetonide (STTA) for idiopathic macular telangiectasia. METHODS Seven eyes (seven patients; mean age, 72 years) were enrolled, five eyes with type 1 and two eyes with type 2. The mean follow-up was 10.6 months (range 7 to 19). FA and IA were performed with the Heidelberg Retina Angiogram 2. Laser photocoagulation was applied to leaky vessels detected by late-phase IA (wavelength, 577 nm; power, 100-200 mW; spot size, 100-200 microm; and duration, 0.2 s). STTA (20 mg) was injected after photocoagulation. The central macular thickness and macular volume were measured periodically by optical coherence tomography. The logarithm of the minimum angle of resolution (logMAR) visual acuity (VA) was measured. RESULTS IA identified leaky aneurysms or vessels. The final mean logMAR VA and the central macular thickness improved significantly from baseline (p=0.040, p=0.0002, respectively). The VA improved by 0.3 or more logMAR unit in two eyes (29%) and stabilised in five eyes (71%). No adverse effects were reported throughout follow-up. CONCLUSIONS IA can detect microangiopathy in eyes with idiopathic macular telangiectasia. IA-guided laser photocoagulation combined with STTA might be effective for treating types 1 and 2 idiopathic macular telangiectasia. Further studies are needed to access the efficacy of IA-guided photocoagulation for treating type 2 telangiectasia.