Abstract
Purpose :
Macular telangiectasia type 2 (MacTel) is a slowly progressing neurovascular disease of the macula, currently lacking any effective treatment. This study was designed to assess the effect of non-damaging retinal laser therapy (NRT) using PASCAL laser with Endpoint Management algorithm compared to sham laser.
Methods :
Twenty study eyes of 12 previously untreated patients diagnosed with MacTel were enrolled in this double-masked, sham-controlled randomized clinical trial. Both eyes could be randomized 1:1 to either NRT using 30% energy or to the same pattern treatment with zero power (SHAM). Patients were retreated with same parameters every six months. Structural outcome measure was difference in area of ellipsoid zone (EZ) disruption after 12 months measured by enface SS-OCT (TOPCON TRITON PLUS). Functional outcomes included best corrected visual acuity and macular automated perimetry (CENTERVUE COMPASS, USA) at 12 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 66.55 +/- 12.69 letters for SHAM and 70.80 +/- 9,77 letters for NRT eyes (p=0.245), and EZ loss was 298 +/- 104μm2 for SHAM and 368+/- 116 μm2 in NRT group (p=0.391). At 12 months, EZ loss increased 24% in sham group, while in NRT group it decreased by 34% (p<0.001). No statistically significant changes in BCVA between groups have been seen compared to baseline, however, SHAM group had worse visual acuity in twelve months compared to NRT (65.60 +/- 3.7 letters vs 73.23 +/- 1.88 letters, p=0.035). After one-year, central macular sensitivity was significantly higher for NRT group (28.22 +/- 0.71Db) compared to SHAM (25.86 +/- 1.13Db, p=0.028) and total fixation area was larger for SHAM compared to NRT group (7.94 +/- 2.7 vs 3.47 +/- 1.46, p< 0.001). No adverse events related to laser treatment have been identified.
Conclusions :
NRT was safe and well tolerated in patients with MacTel and it significantly decreased the EZ disruption compared to SHAM treatment at 12 months, which could represent a neuroprotective effect of the laser-induced hyperthermia below the damage threshold. Statistically significant differences between groups in long term visual acuity and retinal sensitity was reported, but due to limitations of this trial, these relevant results should be confirmed in larger clinical trials.
This is a 2020 ARVO Annual Meeting abstract.