Assessment for Macular Thickness after Uncomplicated Phacoemulsification Using Optical Coherence Tomography

Macular edema including cystoid macular edema is one of the main causes of unfavorable visual outcomes after cataract surgery. The macular thickness and the occurrence of macular edema after uncomplicated cataract surgery was evaluated using optical coherence tomography (OCT) in this study.

Macular map images were taken by OCT before surgery and at 1 week, 1 month, and 2 months postsurgery. The subjects were classified into two groups (group 1, patients with no macular edema; group 2, patients with macular edema). Group 2 was defined as increase in central macular thickness (CMT) by 30% compared with that before surgery. The risk factors for macular edema were evaluated. Group 2 was divided into two subgroups: subclinical macular edema (group 2A) and cystoid macular edema (group 2B) and they were assessed in terms of the clinical course of best-corrected visual acuity and CMT.

A total of 376 patients were enrolled in this study, of which 36 (9.57%, group 2) showed macular edema measured by OCT after the surgery. Univariate analysis for group 1 and 2 revealed that intracameral injection of epinephrine during phacoemulsification was associated with the development of macular edema. In group 2, five patients (1.33%) developed cystoid macular edema. Statistically significant differences in the clinical course of CMT were observed at 2 months (201.2 ± 23.1, 250.0 ± 29.8, and 371.0 ± 160.3 in group 1, group 2A, and group 2B, respectively; p < 0.001) and 1 month postoperatively (198.5 ± 23.6, 237.8 ± 40.9, and 314.0 ± 104.5 in group 1, group 2A, and group 2B, respectively; p < 0.001). Group 2B required additional treatment and eventually achieved best-corrected visual acuity of >0.2 with CMT in the normal range.

The intracameral injection of epinephrine may cause macular edema after uncomplicated cataract surgery. Examination of CMT using OCT is recommended for the early detection of macular edema.