Remote temperature control as a method for dosing effects during transscleral laser coagulation of the retina

Boiko E.V. ^1-3, Suetov A.A.^{1, 3}, Izmaylov A.S.¹, Doktorova T.A.¹, Ivanov A.A.⁴

Background. Transscleral laser coagulation in retinal pathology have important advantages in cases of reduced transparency of optical media and the need for treatment on the periphery of the fundus. However, optical media opacities make it challenging to accurately assess the severity of the burns that occur, so the development of more precise dosing methods, including automated ones, could help to make transcleral laser coagulation a more effective and safe treatment option and allow its use in routine clinical practice.

Aim. To investigate the relationship between temperature and its variations on the scleral surface and the intensity of laser burns during transscleral laser coagulation of the retina.

Materials and methods. An experimental study was conducted on five rabbits (10 eyes). Transscleral laser exposure was performed using a diode laser (Alod-01, Alkom Medica, 810 nm) with a power of 0.2 W and a spot diameter of 300 microns on the surface of the sclera. The temperature was measured remotely using a thermal camera (Guide MobIRAir, China) on the surface of the sclera at the point of exposure. The severity of coagulation injury was characterized as barely visible, mild, moderate and intense burns, and for each level, the duration of exposure, temperature, and temperature difference on the surface of the sclera at the point of exposure were taken into consideration.

Results. The formation of barely visible burns occurs when the temperature on the surface of the sclera rises by 2.10 ± 0.320 °C, mild burns - by 2.44 ±0.270 °C, moderate burns - by 2.87 ±0.310 °C and intense burns - by 3.39 ±0.240 °C. A correlation was found between the temperature gradient on the surface of the sclera in the laser exposure zone and the time of burn formation at all intensities considered (r>0.45, p<0.05).

Conclusion. During transscleral laser coagulation of the retina, the temperature on the surface of the sclera at the point of exposure increases and correlates with the time and intensity of burns formed on the fundus.

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