Transscleral Diode Laser Coagulation With Temperature Control of Burn Intensity as a New Approach to Metered Laser Effects on the Fundus

Purpose: The purpose of this study was to investigate the relationship between changes in temperature on the surface of the sclera and the intensity of retinal burns during transscleral diode laser coagulation. Methods: Transscleral diode laser coagulation of the fundus was performed on 20 eyes from 10 chinchilla rabbits, using laser radiation of different powers ranging from 0.16 to 0.28 W. IR thermography was used to investigate temperature changes on the scleral surface at the point of exposure during the development of retinal burns of varying intensity. The time of burn formation, the morphology of burns, their diameter, and the depth of damage to the choroid and sclera were also studied using optical coherence tomography (OCT) and histological examination. Results: The temperature change on the sclera's surface during the formation of burns of varying intensity and using different power ranged from 1.42 ± 0.43 to 4.08 ± 0.35°C, whereas the average burn formation time ranged from 1.58 ± 0.44 to 21.85 ± 1.69 seconds. A correlation was found between the change in the temperature on the surface of the sclera and the depth of damage to the choroid and sclera, with an increase in laser radiation power from 0.16 to 0.28 watts (W), for different levels of burns severity. Conclusions: During transscleral diode laser retinal coagulation, the intensity of the burns formed is related to the temperature change on the scleral surface at the point of exposure. Translational Relevance: The approach developed in the study can be used to create an automated laser system for transscleral diode-laser retinal coagulation with control of the intensity of burns.