Purpose
To evaluate the safety and preliminary efficacy of intravitreal ranibizumab for non-neovascular idiopathic macular telangiectasia, type 2 (IMT2).
Methods
Single-center, open-label phase II clinical trial enrolling 5 participants with bilateral non-neovascular IMT2. Intravitreal ranibizumab (0.5mg) was administered every 4 weeks in the study eye for 12 months with the contralateral eye observed. Outcome measures included changes in: best corrected visual acuity (BCVA), area of late-phase leakage on fluorescein angiography (FA), and retinal thickness on optical coherence tomography (OCT).
Results
The study treatment was well-tolerated and associated with few adverse events. Change in BCVA at 12 months was not significantly different between treated study eyes (0.0±7.5 letters) and control fellow eyes (+2.2±1.9 letters). However, decreases in the area of late-phase FA leakage (−33±20% for study eyes, +1±8% for fellow eyes) and in OCT central subfield retinal thickness (−11.7±7.0% for study eyes and −2.9±3.5% for fellow eyes) were greater in study eyes compared to fellow eyes.
Conclusions
Despite significant anatomical responses to treatment, functional improvement in visual acuity was not detected. Intravitreal ranibizumab administered monthly over a time course of 12 months is unlikely to provide a general and significant benefit to patients with non-neovascular IMT2.