Year: 2005
Type: article
Abstract: Selective retinal photocoagulation uses short pulsed lasers to coagulate retinal pigment epithelium selectively, while sparing the photoreceptors.The problem associated with the usage of short pulsed laser is the difficulty in determining the correct dosimetry parameters.This study quantifies the influence of laser parameters and variation of thickness and melanin concentration of RPE over the therapeutic range.The laser-tissue interaction is numerically investigated by analyzing the transient temperature in ocular tissues during the treatment.The rate process analysis for thermal injury is employed to estimate the selective damage of retina.The contours of Arrhenius integral value (Ω/Ω max ) presented in this study show both the area and magnitude of damage caused by various laser parameters.Results reveal that the 2 µs pulsed-laser with green wavelength and Gaussian profile is relatively more effective for selective retinal treatment.The repetition frequency of 100 Hz selectively damages RPE, while frequency of 1000 Hz produces damage to neural retina and choroid located within 2 µm from RPE interface.However, the Ω max value for 1000 Hz is orders of magnitude (~ 2000 times) greater than that for100 Hz.The amount of threshold energy required for 14 µm thick RPE is ~25% less than that for 10 µm thick RPE, while 6 µm thick RPE requires ~35% more energy.
Author: Pradeep Gopalakrishnan
Institution: University of Cincinnati
Language: English
Subfield: Ophthalmology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2249093280