The Impact of Blood Perfusion and Laser Parameters on Heat Transfer During Retinal Laser Irradiation

ABSTRACT Retinal laser therapies assume a critical function within the field of ophthalmology, since the human eye is exposed to a multitude of ocular disorders, and diabetics and individuals with prolonged hypertension levels are at significant risk of developing retinal disease. Accurate modeling of the thermal behavior of ocular tissues is critical to optimizing treatment efficacy while minimizing adverse effects. In this paper, a novel finite element model is studied for the analysis of the thermal effects of two types of laser therapies on the retina. Two common laser wavelengths used in ophthalmology are simulated: 532 nm for pan‐retinal photocoagulation and 810 nm for transpupillary thermotherapy. The effects of optical properties, such as absorption, scattering, and anisotropy index are incorporated. Also included are melanin granules in the retinal pigment epithelium, vascular networks in the neural retina and choroid, and fluid dynamics in the posterior segment of the eye. Some of the key limitations of previous approaches are overcome by the model. In addition, a comparative analysis is carried out between two intensity profiles: Top‐Hat and Gaussian beams. The results show that Gaussian and Top‐Hat laser beam profiles significantly affect thermal distributions, underscoring the critical role of beam shape and laser parameters in optimizing therapeutic outcomes. Sensitivity analysis showed that changes in perfusion of shifted the peak temperature by less than 0.2 . Therefore, while perfusion helps to dissipate heat, it remains secondary to the beam profile and vitreous convection.