Photo Credit: miodrag ignjatovic

The following is a summary of “Progressive inner retinal neurodegeneration in non-proliferative macular telangiectasia type 2,” published in the September 2024 issue of Ophthalmology by Amram et al.

People with non-proliferative macular telangiectasia type 2 (MacTel) often experience thinning in the ganglion cell layer (GCL) and nerve fiber layer (NFL). However, it is still unclear whether this thinning worsens over time.

Researchers conducted a retrospective study measuring the changes in retinal layer thickness in patients with MacTel, comparing those with and without diabetes. 

They reviewed data from multiple centers, selecting patients with MacTel with a history of at least 2 OCT scans taken over 9 months apart. Using Iowa Reference Algorithms, NFL and GCL thickness was measured across specific retinal areas. Mixed effects models were applied to track thinning rates over time for each layer. 

The results showed that a total of 115 patients with Mactel were included, with 57 (50%) having diabetes and 21 (18%) having a history of carbonic anhydrase inhibitor (CAI) treatment. Thinning rates were similar for patients with and without diabetes. In people with diabetes and untreated with CAIs, the temporal parafoveal NFL thinned at a rate of −0.25±0.09 µm/year (95% CI [−0.42 to –0.09]; P=0.003). The CGL in subfield 4 thinned faster in eyes treated with CAIs (−1.23±0.21 µm/year; 95% CI [−1.64 to –0.82]) compared to untreated eyes (−0.19±0.16; 95% CI [−0.50, 0.11]; P<0.001), which was also observed in the inner nuclear layer. Progressive outer retinal thinning was noted.

Investigators concluded that patients with MacTel experience ongoing inner retinal neurodegeneration similar to those with diabetes who do not have diabetic retinopathy. More research is needed to grasp the effects of this retinal thinning in MacTel.

Source: bjo.bmj.com/content/early/2024/09/17/bjo-2023-325115