To investigate the retinal light hazard during macular surgery using a digital three-dimensional visualization system (3D) and a conventional microscope (CM).
Experimental study and retrospective evaluation of a case–control study.
A total of 20 and 10 patients who underwent pars plana vitrectomy for epiretinal membrane using 3D and CM, respectively.
Spectral irradiances of endoilluminators were measured for representative settings used during core vitrectomy and macular manipulations with 3D and CM. From the medical record of the patients, time needed for core vitrectomy and macular manipulations was extracted. The total retinal light hazard index and the macular hazard index were calculated based on the spectral irradiances weighted by the standard functions. Total retinal light hazard index, macular hazard index, and the number of cases that exceeded the maximum permissible radiant power exposure were compared between the two groups.
The spectral irradiance were 1.6 and 3.9 mW/cm2 for core vitrectomy and 3.4 and 8.1 mW/cm2 for macular manipulations using typical settings for 3D and CM groups, respectively. The total retinal light hazard index ranged from 4.31 kJ/m2 to 17.37 kJ/m2 for 3D and 11.09 kJ/m2 to 27.70 kJ/m2 for CM groups, respectively, whereas the macular hazard index ranged from 2.93 kJ/m2 to 14.58 kJ/m2 for 3D and from 6.84 kJ/m2 to 23.55 kJ/m2 for CM, respectively (P < 0.001). One (5%) and 6 (60%) pars plana vitrectomy cases exceeded the threshold limits with 3D and CM groups, respectively (P < 0.05, chi-square test).
The 3D digitally assisted visualization system offers significantly safer macular surgery compared with the CM, considering the potential retinal hazard.