Factors affecting pseudophakic cystoid mascular edema: five randomized trials.

We summarize the findings of five randomized prospective, controlled studies that evaluated the following factors associated with the development of cystoid macular edema (CME) following cataract surgery: ultraviolet (UV) light from the operating microscope; postoperative UV light exposure; primary capsulotomy; retrobulbar hyaluronidase; and prostaglandin synthesis in the eye. The following were the major findings: (1) The presence of a UV-light filter on the operating microscope during cataract surgery made no statistically significant difference in the early postoperative (two to six months) angiographic incidence of CME or the visual outcome. (2) A UV-filtering posterior chamber intraocular lens (IOL) resulted in a statistically significant decrease in the early postoperative incidence of angiographic CME in postcataract-surgery patients but did not affect visual acuity. (3) Patients receiving primary capsulotomy during extracapsular cataract surgery showed a statistically significant higher incidence of early postoperative angiographic CME than did patients with an intact posterior capsule. Again there was no difference in visual acuity. (4) The addition of hyaluronidase to the retrobulbar anesthetic injection made no significant difference in the CME rate or postoperative visual results of patients undergoing extracapsular cataract surgery. (5) Patients undergoing IOL implant surgery who received topical indomethacin before surgery and for nine months postoperatively to inhibit prostaglandin synthesis in the eye showed a statistically significant lower incidence of early postoperative angiographic CME than did placebo-treated patients, but there was no significant difference between the two groups in postoperative visual acuity.