DMEK-induced iris damage may increase risk of CME

This retrospective study examined the factors associated with cystoid macular edema (CME) after Descemet membrane endothelial keratoplasty (DMEK).

Study design

Researchers assessed 77 eyes (65 patients) that underwent DMEK surgery in Japan. Fifty-three eyes underwent cataract surgery 1 month prior to DMEK (staged DMEK) while 24 eyes underwent DMEK alone.

Multivariable analysis included the type of surgery, iris damage scores, age, sex, axial length, preoperative visual acuity, rebubbling rate, air volume on postoperative day 1, diabetes history and cell density loss after 6 months.

Outcomes

The rate of postoperative CME was 15.6%; all cases occurred within 1 month of surgery. Factors associated with CME included increased iris damage scores (OR 16), air volume in the anterior chamber (OR 2.3x10^-4), DMEK without cataract surgery (OR 14) and rebubbling (OR 18).

Limitations

All study participants were of Asian descent so results cannot be extrapolated to all patient populations. A large proportion of patients (36%) underwent DMEK as a result of bullous keratopathy from argon laser peripheral iridotomy. The reason for DMEK surgery was not included in the analysis but may have led to the high rate of CME.

Clinical significance

In this study, the incidence of CME after DMEK was 15.6%. Factors that increase inflammation were associated with postoperative CME, especially iris trauma during surgery. The use of a preoperative NSAID may have contributed to the lower CME rates seen in the staged surgery group. The authors recommend frequent OCT imaging to monitor patients in the first 6 months following DMEK surgery.