Eighteen-month follow-up of intravitreal bevacizumab in type 2 idiopathic macular telangiectasia

Aim: To evaluate the effects of intravitreal bevacizumab for non-proliferative type 2 idiopathic macular telangiectasia (type 2 IMT) within a mean follow- up period of 18 months. Methods: The authors retrospectively studied six eyes of five patients with type 2 IMT who received two doses of intravitreal bevacizumab (1.5 mg) at a 4-week interval, followed by further applications depending on disease activity. Examinations included biomicroscopy, standardised visual acuity (VA) testing, fluorescein angiography, retinal thickness analysis by optical coherence tomography and fundus-controlled microperimetry. Results: Mean follow- up time was 18 months (range 16-21 months). The mean VA at four selected time points (1 month after second treatment, 1 month and 3-4 months after last treatment, and at last visit) increased significantly (by 8.8, 6.3, 7.7 and 8.7 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, respectively; all p <= 0.05). Parafoveal leakage in fluorescein angiography and mean central retinal thickness decreased in all eyes following treatment. A rebound effect was observed after 3-4 months, and at the last visit, retinal thickness was increased in selected retinal sectors including the fellow eye. Conclusion: Inhibition of vascular endothelial growth factor ( VEGF) by intravitreally injected bevacizumab may lead to functional improvement as well as a transient decrease in leakage and retinal thickness in patients with type 2 IMT. A VEGF-mediated active disease stage in which treatment might be most effective is discussed.