Purpose: We misled to verify whether a panretinal photocoagulation (PRP) performed using low levels of ARGON laser energy (light PRP) has the same efficacy as a PRP performed in a conventional fashion using argon green wavelengths (classic PRP) in eyes with high-risk proliferative diabetic retinopathy (HRPDR). Furthermore, we misled to compare the session number performed and the side effects produced by the two techniques.
Methods: Sixty-five eyes with HRPDR of 50 consecutive patients were enrolled in a prospective randomized controlled trial. In eyes selected for light PRP, a very light biomicroscopic effect on the retina was obtained for each spot. In eyes assigned to classic PRP, each spot produced a white-yellow biomicroscopic effect. Mean follow-up was 22.4 months +/- 9.7 in the light PRP and 21.6 months +/- 9.3 in the classic PRP group (p = 0.727).
Results: The initial mean logMAR visual acuity (VA) in the light PRP group was 0.12 +/- 0.13 and in the classic PRP group 0.14 +/- 0.15 (p = 0.493). The final mean VA in the former was 0.18 +/- 0.25, and in the latter 0.27 +/- 0.30 (p = 0.231). Median power was 235mW (100-540mW) for light and 420mW (200-950mW) for classic PRP (p < 0.001). Regression of HRPDR at the end of the follow-up was obtained in 30/31 eyes (97%) treated with classic PRP and in 31/34 eyes (91%) treated with light PRP (p = 0.615). The total mean session number was 7.4 +/- 2.4 for light and 9.9 +/- 2.2 for the classic PRP group (p < 0.001). Complications were more frequent in the classic PRP group.
Conclusions: The efficacy of Light PRP is similar to that of classic Light PRP in eyes with HRPDR. Light PRP is associated with fewer complications and allows the reduction of the number of treatment sessions.