Comparison of conventional pattern and novel navigated panretinal photocoagulation in proliferative diabetic retinopathy

Invest Ophthalmol Vis Sci. 2014 May 1;55(6):3432-8. doi: 10.1167/iovs.14-13936.


Purpose: To compare the laser spot quality between the conventional slit lamp pattern laser (PASCAL) and the navigated pattern laser (NAVILAS) for panretinal photocoagulation (PRP).

Methods: Prospective randomized interventional trial of 73 eyes (51 patients) with high-risk proliferative diabetic retinopathy. Eyes underwent PRP using 30-ms pulse duration with either PASCAL (16 eyes) or NAVILAS laser (21 eyes), or 100-ms pulse duration with either PASCAL (16 eyes) or NAVILAS laser (20 eyes). Fundus color images of all quadrants were taken 5 minutes after treatment. Laser burn size (major and minor diameter and area) and ellipticity (ratio of minor to major axis) were analyzed across the retina. Treatment time and pain were compared between both groups.

Results: The burn size variation in navigated laser 30 ms, 100 ms, and conventional pattern 30 ms and single-spot 100 ms laser was 22%, 24%, 21%, and 35%, respectively. The variation of the laser burn area near the arcade for NAVILAS and for PASCAL was 29% and 22%, respectively (P < 0.01). Closer to the equator, burns from the NAVILAS showed even smaller variation of 15% compared with 25% with PASCAL (P < 0.005). Laser spots from PASCAL exhibited an increasing elliptical shape toward the periphery, whereas NAVILAS laser spots tended to be more uniform all over the retina. Average treatment duration and pain experience was less with navigated laser compared with pattern laser (P ≤ 0.05).

Conclusions: Navigated laser treatment achieves more uniform laser burns with less pain during shorter treatment duration in comparison with conventional pattern laser.

Keywords: NAVILAS; PASCAL; navigated laser; panretinal photocoagulation; slit-lamp laser system.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Diabetic Retinopathy / diagnosis
  • Diabetic Retinopathy / surgery*
  • Female
  • Fluorescein Angiography
  • Follow-Up Studies
  • Fundus Oculi
  • Humans
  • Laser Coagulation / methods*
  • Lasers, Solid-State / therapeutic use*
  • Male
  • Middle Aged
  • Prospective Studies
  • Retina / pathology
  • Retina / surgery*
  • Treatment Outcome
  • Visual Acuity
  • Vitreous Body / pathology
  • Vitreous Body / surgery*