Evaluation of Fundus Radiation Intensity During Femtosecond Photoemulsification Cataract Surgery.

OBJECTIVES

Femtosecond 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

METHODS

A 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.

RESULTS

At 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.

CONCLUSIONS

The 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.