Purpose: To evaluate the visual acuity (VA) and optical coherence tomography thickness results of short-duration pattern scanning laser macular photocoagulation in the treatment of clinically significant macular edema because of diabetes.
Methods: Consecutive retrospective analysis of VA and optical coherence tomographic data from eyes treated in a modified Early Treatment Diabetic Retinopathy Study style using a short-duration pattern scanning laser.
Results: A total of 100 eyes from 70 patients met study criteria. All subjects were treated with the same PASCAL (pattern scanning laser) photocoagulation unit. Parameters varied according to media and pigmentation status, but typical settings were 100-μm spot size, 10-millisecond pulse duration, 225-mW power, and 29 J/cm fluence to give a pale but visible lesion. At 4 months posttreatment, there was an average improvement in VA of 0.060 logMAR (an improvement from 20/45 to 20/40, or approximately 3 Early Treatment Diabetic Retinopathy Study letters; P = 0.0007) and a reduction of central optical coherence tomographic thickness of 40 μm and 37 μm (spectral domain and time domain optical coherence tomography groups, respectively), both of which were statistically significant (P = 0.0049 and 0.012, respectively).
Conclusion: Short-duration PASCAL macular photocoagulation has a biological treatment effect at 4 months for the treatment of clinically significant macular edema. While caution must be used when converting between different VA measurement methods and when using literature-based controls, the observed VA improvement seems equivalent to 3 Early Treatment Diabetic Retinopathy Study letters. These findings are similar to the recently published results from the diabetic retinopathy clinical research network cohort. PASCAL laser photocoagulation for clinically significant macular edema appears safe and effective in the short term and may have significant long-term advantages.