Clinical characteristics, imaging features, and treatment outcomes of macular telangiectasia type 2: a comprehensive meta-analysis

Macular telangiectasia type 2 (MacTel type 2) is a rare bilateral retinal neurodegenerative disorder characterized by parafoveal capillary dilation and progressive photoreceptor loss, potentially leading to visual impairment. Despite increasing recognition, uncertainties remain regarding its diagnosis and optimal management. This study aimed to comprehensively summarize the demographics, clinical characteristics, management, and prognosis of MacTel type 2. PubMed, EMBASE, and Ovid were searched from inception to March 2024. Statistical analyses were performed with R 3.6.3. A total of 205 studies comprising 11,045 patients were included. MacTel type 2 showed female- predominance (male ratio: 38%) and was frequently associated with metabolic comorbidities, including hypertension (41%), diabetes mellitus (35%), and dyslipidemia (33%). More than half (55%) of patients had a BCVA better than 20/40, and 12% presented with proliferative disease. In the proliferative stage, anti-VEGF therapy resulted in visual improvement in 59% of patients, compared with 7% under observation. In the non-proliferative stage, anti-VEGF therapy and observation yielded improvement rates of 58% and 31%, respectively. Among patients with full-thickness macular hole, pars plana vitrectomy (PPV) with internal limiting membrane (ILM) flap demonstrated higher MH closure rates (92% vs. 44%) and better visual outcomes (60% vs. 45%) than PPV with ILM peeling. MacTel type 2 mainly affects females, usually associated with metabolic comorbidities, and generally causes mild visual impairment. Anti-VEGF therapy may offer greater benefit over observation in the proliferative stage, whereas its effectiveness in non-proliferative disease remains uncertain. For patients complicated with full-thickness macular holes, PPV assisted with an ILM flap provides superior anatomical and visual outcomes compared with ILM peeling.