Variability of thermal subthreshold retinal laser treatment plans

Abstract To investigate the variability in subthreshold laser treatment plans for patients with diabetic macular edema or central serous chorioretinopathy. Diagnostic images from 20 patients were utilized, and 25 retina specialists generated subthreshold treatment plans along with a self-rated experience level. Evaluation comprised of i) Area Variability (AV): quantifies the consensus regarding the covered area and is the difference between the areas planned by 75% and 25% of the participants ii) mean Centroid Distance (CD): level of agreement on the localization of a treatment. Subgroup analysis investigated the impact of participants’ experience levels, utilizing the Mann-Whitney-Wilcoxon test. The predominant plan style is a targeted treatment approach (92%) and avoidance of subfoveal region (89%). Mean CD is 71.0 ± 37.5 pixels (≈half disc diameter) and mean AV is 9.8%±8.9%. A slight difference is observed between the 50-75% areas, but a notable distinction exists between the 25-50% areas. Subgroup analysis revealed CD and AV value of 75.9 pixels and 24% in the lower experience level group as opposed to 55.9 pixels and 8.6% in the higher experience level group. There is significant variability in treatment planning which reduces with increased experience of retina specialists. While consensus is observed around focal points, differences in the surrounding extents persist.