Microscope-induced retinal phototoxicity in cataract surgery of short duration

Objective: Microscope-induced retinal phototoxicity has been described after prolonged cataract surgery, usually in operations lasting longer than 100 minutes. The purpose of this study was to compare the features of microscope-induced retinal phototoxicity occurring in patients who underwent cataract surgery of short duration and long duration. Design: A retrospective nonrandomized comparative trial. Participants: Thirty-four patients, whose medical records documented the development of phototoxic lesions in the retina as a result of cataract surgery, were divided into two groups: group A with 14 patients whose operating time was 30 minutes or less, and group B with 20 patients whose operating time was greater than 30 minutes. Intervention: All patients underwent either phacoemulsification or extracapsular cataract extraction (ECCE) with implantation of an intraocular lens. Results: The mean operating time was 23.1 minutes (range, 11-30 minutes) in group A, and 60.8 minutes (range, 34-123 minutes) in group B. Phacoemulsification was done more often in group A (P = 0.001) and ECCE in group B (P = 0.0003). A final refraction of ± 1 D was achieved by 12 eyes (86%) in group A and by 12 eyes (60%) in group B (P = 0.11). The correlation between final refraction and duration of the operation was significant; the closer the final refraction approached to emmetropia, the shorter the duration of surgery (r = 0.53; P = 0.001). Diabetic retinopathy was more common in group A (P = 0.03). Conclusions: Phototoxic lesions of the retina may occur during cataract surgery even when the duration of the operation is short. The most relevant associated factors found in this study were correction approximating emmetropia and diabetic retinopathy.