Objective: To evaluate the incidence, effect on visual recovery, and predisposing risk factors of postvitrectomy macular edema (ME).
Design: Prospective cohort study.
Participants: One-hundred nine eyes undergoing nonemergent vitrectomy surgery.
Methods: Eyes were evaluated for postoperative day 1 inflammation, 1-month retinal thickness using optical coherence tomography, and preoperative and 1-month postoperative best-corrected visual acuity (BCVA). Macular edema was defined as central subfield thickness > or =272 microm.
Main outcome measures: Retinal thickness, inflammation, and BCVA.
Results: Incidence of ME on optical coherence tomography was 47% (95% confidence interval [CI], 37%-56%). Mean 1-month visual acuity improved 3.3 lines (0.33 logarithm of minimum angle of resolution [logMAR] units) to 20/80(+1) (0.58+/-0.46 logMAR units) from 20/150(-2) (0.91+/-0.63 logMAR units) before surgery (P<0.001). Mean 1-month center point thickness (CPT), central subfield (CSF), and total macular volume were 265+/-107 microm, 288+/-94 microm, and 7.8+/-1.2 mm(3), respectively. Severity of postoperative inflammation predicted retinal thickness at 1 month (P<0.05). Intraoperative epinephrine use was associated with increased postoperative inflammation (P = 0.02). Eyes with greater reduction in CSF (or CPT) from baseline experienced more rapid visual recovery (r = -0.36; 95% CI, -0.61 to -0.06; P = 0.02).
Conclusions: Postvitrectomy ME is common and delays visual recovery. Degree of postoperative inflammation is an important risk factor for ME and, in this series, was increased in the setting of intraocular epinephrine. Efforts to reduce or prevent inflammation after vitrectomy should be beneficial and therefore are encouraged.