Evaluation of the safety of xenon/bandpass light in vitrectomy using the A2E-laden RPE model

Background The purpose of the study was to investigate the brightness of the xenon/bandpass light in vitrectomy and assess its phototoxic effects using A2E-laden retinal pigment epithelial (RPE) cells. Methods The total luminous flux and spectral irradiance of 20- and 25-gauge endoilluminators connected to xenon lamps were measured and compared to those of 20- and 25-gauge endoilluminators connected to a halogen lamp. In vitro, A2E-laden cells were evenly exposed to xenon/bandpass light for 5 to 30 min positioned at 1 cm and 2 cm for a standard light probe and an implantable “chandelier” light probe, respectively, above the cells, and the cell viability was assessed using WST-1 assay. The cell viability was compared with cells exposed to 30 min of halogen light projected through a 20-gauge endoilluminator. Results The maximal total luminous flux of xenon/bandpass light emitted through the 20-gauge endoilluminator was 2.8 times higher than that of the halogen light. The total luminous flux of the 25-gauge endoilluminators was 0.6-1.1 times greater than the 20-gauge endoilluminators connected to the halogen light. The viability of the A2E-laden cells after exposure to the xenon/bandpass light was no different than that of the cells exposed to the halogen light when the total luminous flux of these lights was at the same level. Xenon/bandpass light from an implantable “chandelier” light probe induced A2E-mediated RPE damage to a similar extent as that of the halogen light through a 20-gauge endoilluminator. Conclusions A2E-mediated phototoxicity of xenon/bandpass light is comparable to that of halogen light.