Spectral-domain optical coherence tomography imaging of retinal changes after conventional multicolor laser, subthreshold micropulse diode laser, or pattern scanning laser therapy in Japanese with macular edema.

PURPOSE: To perform optical coherence tomography imaging of retinal healing after conventional multicolor laser, pattern scanning laser, or micropulse laser treatment and compare the characteristics of each method.
METHODS: This was a single-center interventional case series study. Twenty-nine patients with macular edema underwent laser photocoagulation. Changes of retinal morphology because of laser-tissue interaction were assessed within 3 months by using a spectral-domain optical coherence tomography.
RESULTS: Immediately after conventional multicolor laser or pattern scanning laser treatment, a hyperreflective band appeared at the laser sites. The photoreceptor inner segment-outer segment line disappeared in all the patients treated with a conventional multicolor laser, but was intact in 22.2% (2/9 eyes) after pattern scanning laser. From 1 week to 1 month, the bands resolved. At 3 months, recovery of the inner segment-outer segment line surrounding the laser site was seen in all patients after conventional grid photocoagulation and pattern scanning laser. Retinal morphology did not change at any time during the observation period after subthreshold micropulse diode laser photocoagulation.
CONCLUSION: The characteristic in vivo effects of retinal photocoagulation were monitored over time by spectral-domain optical coherence tomography. Changes of retinal morphology appeared less intense after pattern scanning laser than conventional grid laser treatment.