Comparison of 577-nm Multispot and Standard Single-Spot Photocoagulation for Diabetic Retinopathy

Ophthalmologica. 2019;241(4):202-210. doi: 10.1159/000493280. Epub 2018 Oct 17.


Objective: To compare two different laser strategies of panretinal photocoagulation for diabetic retinopathy.

Methods: Single-center, randomized study including 41 eyes treated with 577-nm multispot laser with a 20-ms pulse duration (group 1) or a 532-nm single-spot laser with a 100-ms pulse duration (group 2). The outcomes included best-corrected visual acuity (BCVA) and imaging changes at baseline, 6 and 12 months, laser parameters, and results of subjective pain analysis.

Results: At 12 months, the treatments did not differ significantly in BCVA, central retinal thicknesses (CRTs), improved macular edema, vitreomacular interface changes, patient-reported pain scores, or angiographic responses. Group 1 had significantly fewer treatment sessions but used more laser spots (p < 0.001).

Conclusion: The multispot laser required fewer applications with more spots delivered to compensate for lower fluency, showing similar patient tolerance to single-spot laser. Both groups maintained the initial visual acuities and CRTs; about 50% of cases had vitreomacular interface changes and improved macular edema, with similar angiographic improvements after 12 months.

Keywords: Diabetic retinopathy; Multispot laser; Panretinal photocoagulation; Standard photocoagulation.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Diabetic Retinopathy / diagnosis
  • Diabetic Retinopathy / surgery*
  • Female
  • Fluorescein Angiography
  • Follow-Up Studies
  • Fundus Oculi
  • Humans
  • Laser Coagulation / methods*
  • Male
  • Middle Aged
  • Prospective Studies
  • Retina / pathology
  • Retina / surgery*
  • Tomography, Optical Coherence
  • Treatment Outcome
  • Visual Acuity*