Evaluation of Fundus Radiation Intensity During Femtosecond Photoemulsification Cataract Surgery.

OBJECTIVESFemtosecond photoemulsification cataract surgery requires a higher total laser dose than conventional femtosecond laser-assisted cataract surgery, raising concerns about potential retinal exposure. This study aimed to develop a method for accurately measuring time-averaged fundus optical power and aperture-averaged irradiance during femtosecond photoemulsification and to evaluate retinal safety under the tested conditions.

MATERIALS AND METHODSA biomimetic cataract eye model was constructed using an artificial cornea, a hydrogen peroxide-induced cataractous rabbit lens, and saline to simulate the ocular media. A femtosecond laser system was used to perform lens fragmentation at pulse energies of 5.0, 6.0, 7.0, and 8.0 μJ. Time-averaged optical power reaching the simulated macular region was measured with a power meter and converted to aperture-averaged irradiance over a 5-mm receiving aperture. Post-ablation bubble morphology was observed using optical microscopy.

RESULTSAt the effective pulse energy of 7.0 μJ, the maximum measured time-averaged aperture-averaged irradiance in the simulated macular region was 0.249 ± 0.025 W/cm2. Even at the excessive pulse energy of 8.0 μJ, the time-averaged aperture-averaged irradiance remained below the 0.7 W/cm2 retinal thermal limit recommended by the ICNIRP/Sliney guideline.

CONCLUSIONSThe measured fundus radiation power during femtosecond photoemulsification remained below the retinal safety threshold, supporting the retinal safety of this surgical mode under the tested conditions.

Abstract from PubMed