Short-term effects of focal argon laser treatment in diabetic maculopathy as demonstrated by optical coherence tomography.

PURPOSE: To assess the short-term effects of argon laser on retinal thickening as demonstrated by optical coherence tomography (OCT). METHODS: A prospectively collected consecutive series of patients undergoing routine focal argon laser treatment for sight-threatening diabetic maculopathy had bilateral OCT performed before laser treatment and 1 hour, 24 hours, and 2 weeks after treatment. The main outcome measure was change in retinal thickness in the region of laser treatment. RESULTS: Forty-six eyes were analyzed. There was a small increase in retinal thickness in the treated area 1 hour after laser treatment, with a mean change from before laser treatment of +2.6 microm (95% confidence interval [CI], +0.2 to + 5.0). However, there was a larger change 24 hours after treatment of +39.0 microm (95% CI, +31.6 to + 46.4) and a significant decrease 2 weeks after treatment of -14.6 microm (95% CI, -21.6 to -7.7) from before laser treatment values. CONCLUSION: Focal argon laser treatment remains the first-line treatment for sight-threatening diabetic maculopathy. This study shows that in the short-term, areas of retinal thickening worsen before settling in response to argon laser treatment as demonstrated by OCT.