Bio‐heat transfer simulation of retinal laser irradiation

Abstract

Retinopathy is a surgical process in which maladies of the human eye are treated by laser irradiation. A two-dimensional numerical model of the human eye geometry has been developed to investigate transient thermal effects due to laser radiation. In particular, the influence of choroidal pigmentation and that of choroidal blood convection-parameterized as a function of choroidal blood perfusion-are investigated in detail. The Pennes bio-heat transfer equation is invoked as the governing equation, and finite volume formulation is employed in the numerical method. For a 500-μm diameter spot size, laser power of 0.2 W, and 100% absorption of laser radiation in the retinal pigmented epithelium (RPE) region, the peak RPE temperature is observed to be 103 °C at 100 ms of the transient simulation of the laser surgical period. Because of the participation of pigmented layer of choroid in laser absorption, peak temperature is reduced to 94 °C after 100 ms of the laser surgery period. The effect of choroidal blood perfusion on retinal cooling is found to be negligible during transient simulation of retinopathy. A truncated three-dimensional model incorporating multiple laser irradiation of spots is also developed to observe the spatial effect of choroidal blood perfusion and choroidal pigmentation. For a circular array of seven uniformly distributed spots of identical diameter and laser power of 0.2 W, transient temperature evolution using simultaneous and sequential mode of laser surgical process is presented with analysis.

A novel patient‐oriented numerical procedure for glaucoma drainage devices

“…The outcome of implementing this kind of approach in different applications has proven to be a success. Incorporating numerical models in techniques for the treatment of eye diseases, such as insertion of GDDs, can aid medical doctors to implement curing methods in humans …”

“…Incorporating numerical models in techniques for the treatment of eye diseases, such as insertion of GDDs, can aid medical doctors to implement curing methods in humans. [7][8][9][10][11][12][13][14][15][16][17] Previous studies carried out on glaucoma filtration surgery and GDDs prove that there is an actual interest in this field. [18][19][20][21][22][23] In the study of Kara et al, 18 numerical simulations have been carried out on Ahmed glaucoma valve, observing reverse flow and fluctuation in pressure control.…”

A Novel Nanoparticle Mediated Selective Inner Retinal Photocoagulation for Diseases of the Inner Retina

“…Several models of heat transfer in biological tissues exist [14], but Pennes bio-heat equation (PBHE) is the most widely used bioheat model [54–56]. In the eye, computational, numerical and experimental aspects of heat transfer during laser irradiation and retinal photocoagulation have been extensively studied previously [11, 28, 47, 48, 57–65]. …”

Meshless Method with Operator Splitting Technique for Transient Nonlinear Bioheat Transfer in Two-Dimensional Skin Tissues

“…In the context of transient nonlinear bioheat transfer, when there is a need to dynamically monitor the changes of temperature in time and space during the bioheat transfer process, some numerical models have been developed for various biological tissues. For instance, Arunn et al [ 12 ] investigated the variation of transient temperature of a 2D human eye computational model using the finite volume method. Trakic et al [ 13 ] predicted the transient temperature rise in a nonlinear heat transfer model of tumor and healthy tissue of mouse by the commercial finite element software FEMLAB.…”