Long-term follow-up of iatrogenic phototoxicity

Purpose. Microscope-induced phototoxicity occurs in up to 28% of patients undergoing anterior-segment surgery, and has also been reported after vitrectomy. Previous studies were hampered by small numbers of patients or limited follow-up. We report the long-term follow-up and complications that occurred in 23 cases of iatrogenic phototoxicity. Methods. We reviewed the records of 23 patients who suffered light-induced retinal injury during anterior or posterior segment surgery. Variables recorded included the (1) duration of follow-up; (2) intraoperative complications; (3) preoperative, immediate postoperative, and final visual acuity; (4) symptoms; and (5) postoperative complications. Results. Nineteen cases occurred during cataract extraction, and 4 cases during vitrectomy. The average duration of follow-up was 34 months (range 1 to 65 months). Mean preoperative visual acuity was 20/90, mean postoperative visual acuity was 20/60, and mean final visual acuity was 20/50. For patients who had cataract extraction, mean preoperative, postoperative, and final visual acuities were 20/90, 20/30, and 20/25, respectively. The values for patients who underwent vitrectomy were 20/90, 20/1100, and 20/1000, respectively. The difference between these two groups was statistically significant (P<.006). Two of 23 patients (9%) developed choroidal neovascularization., one after cataract extraction, and one after vitrectomy. One of 23 patients (4%) developed CME. Conclusions. Phototoxic injury can occur during anterior segment surgery or during vitrectomy. When the injury occurs during anterior segment surgery, the prognosis is generally good, while phototoxic injury from endoillumination carries a much more guarded prognosis. Choroidal neovascularization is an important manifestation of light-induced injury. Its appearance may not be typical and identification requires a high index of suspicion and close follow-up.