Abstract
Purpose :
Macular telangiectasia type 2 (MacTel) is a slowly progressing neurovascular disease of the macula, currently lacking any safe and effective treatment. This study was designed to assess the effect of non-damaging laser therapy (NRT) of the macula using PASCAL laser with Endpoint Management algorithm by comparing it to a sham laser.
Methods :
Single-center, double-masked, sham-controlled randomized clinical trial with previously untreated patients diagnosed with MacTel type 2. One eye of bilateral eligible patient was randomized to NRT macular grid using 30% energy, while the fellow eye was submitted to the same pattern treatment with zero power (SHAM). Unilateral eligible eyes were randomized either to NRT or SHAM treatment. Best corrected visual acuity measurement and OCT imaging were performed at baseline, and after one, three, six, nine and twelve months. Primary outcome was the difference in the area of ellipsoid zone (EZ) loss after 12 months. Patients were retreated with same parameters every six months.
Results :
Out of 12 patients enrolled (age range 48 - 71 years), 11 eyes were randomized to SHAM treatment and 10 eyes to NRT. At baseline, the mean BCVA was 66 letters for SHAM and 70 for NRT eyes, and EZ loss was 319 μm2 for SHAM and 287 μm2 in NRT group (p=0.8). At 12 months, area of EZ loss decreased in the NRT group to 0.64 + 0.31 relative to baseline, while in the SHAM group it grew to 1.25 + 0.55 (p<0.03). No statistically significant changes in BCVA between the groups have been seen compared to baseline, nor adverse events related to laser treatment have been identified.
Conclusions :
NRT using PASCAL laser with Endpoint Management was safe and well tolerated in patients with MacTel. NRT significantly decreased the EZ loss compared to SHAM treatment at 12 months, which could represent a neuroprotective effect of the laser-induced hyperthermia below damage threshold. No effect on visual acuity compared to baseline is expected in this slow progressive disease. Longer follow-up, more advanced functional evaluation and larger number of patients are warranted to confirm the role of NRT in MacTel.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.