Thirty-month follow-up after intravitreal bevacizumab in progressive idiopathic macular telangiectasia type 2

The aim of this study is to evaluate the long-term efficacy of intravitreal bevacizumab (IVB) for eyes with non-proliferative idiopathic macular telangiectasia type 2 (IMT2) and acute vision loss.

In this interventional case series, treatment-naive eyes of 13 consecutive patients with IMT2 were included. Eyes with a recent onset of visual loss were treated with 0.04 ml IVB (n=7). Fellow eyes and eyes of patients without disease progression served as control group (CG) (n=12). Follow-up examinations included ophthalmoscopy, best-corrected visual acuity (BCVA), optical coherence tomography, and fluorescein angiography (FA).

Mean follow-up time was 32±5.7 months in the treatment group (TG) (n=7) vs 29±8.8 months in the CG (n=16). Mean BCVA increased from logMAR 0.47±0.32 at baseline to logMAR 0.33±0.31 (P=0.21) at the last visit in the TG and decreased from logMAR 0.25±0.39 to logMAR 0.30±0.40 in the CG (P=0.17). All patients in the TG showed stabilisation or improvement in vision in Snellen lines in contrast to the CG (χ(2)-test P=0.04). Patients received on average 2.3±1.3 IVB injections. Mean central millimetre thickness in TG and CG was 260±83 and 201±32 μm at baseline vs 237±69 and 199±29 μm at the last visit, respectively (P=0.23 and 0.77). FA revealed a significant decrease of the juxtafoveal staining size at month 3 (P= 0.004) and a slight reduction at the last visit (P= 0.11) in the TG.

Despite an overall moderate effect of IVB treatment, individual patients experience a marked functional and morphological long-term benefit.