Diabetic Macular Edema: Changing Treatment Paradigms

J. Fernando Arevalo

Disclosures

Curr Opin Ophthalmol. 2014;25(6):502-507. 

In This Article

Diabetic Macular Edema After Cataract Surgery

Past studies on patients with diabetes undergoing cataract removal using intracapsular and extracapsular cataract extraction techniques suggest that cataract surgery is a risk factor for incidence of macular edema or worsening of diabetic retinopathy.[24–26] However, other reports indicate that preexisting DME is not needed for macular edema to occur postoperatively. These studies, although, were completed prior to the availability of OCT technology.

The DRCR.net conducted an observational study to evaluate the incidence of central-involved macular edema, as defined by OCT, in eyes without definite central-involved DME immediately prior to cataract surgery. Baker et al.[27] conducted a multicenter, prospective, observational study, 293 participants with diabetic retinopathy without definite central subfield thickening on OCT underwent cataract surgery to estimate the incidence of central-involved macular edema 16 weeks following cataract surgery in eyes with diabetic retinopathy without definite central-involved DME preoperatively. Forty-four percent of eyes had a history of treatment for DME. Sixteen weeks postoperatively, central-involved macular edema was noted in 0% [95% confidence interval (CI), 0–20%] of 17 eyes with no preoperative DME. Of eyes with noncentral-involved DME, 10% (95% CI, 5–18%) of 97 eyes without central-involved DME and 12% (95% CI, 7–19%) of 147 eyes with possible central-involved DME at baseline progressed to central-involved macular edema. History of DME treatment was significantly associated with central-involved macular edema development (P < 0.001). The authors concluded that in eyes with diabetic retinopathy without concurrent central-involved DME, presence of noncentral-involved DME immediately prior to cataract surgery or history of DME treatment may increase the risk of developing central-involved macular edema 16 weeks after cataract extraction.

Patel et al.[28] reported that in patients with diabetes, the VEGF levels in the aqueous humor peak 1 day after cataract surgery and normalize 1 month after cataract surgery. These findings suggest that anti-VEGF drugs may prevent postoperative diabetic macular edema PME in cataract patients with diabetic retinopathy.[29]

Chae et al.[30] conducted a randomized, controlled, trial to evaluate whether intravitreal ranibizumab injection at cataract surgery prevents PME in patients with stable diabetic retinopathy without significant macular edema. Compared with the ranibizumab injection group, the sham group had significantly larger central subfield thickness increases relative to baseline at 1 week and 1 month; larger total macular volume increases at all time points (P = 0.012, P = 0.005, P < 0.001, P < 0.001, P = 0.005, P = 0.017, respectively); higher PME frequency at 1 month (P = 0.019); and poorer BCVA improvement from baseline to 6 months after surgery (P = 0.046). The authors concluded that in patients with stable diabetic retinopathy without significant macular edema, intravitreal ranibizumab injection at cataract surgery may prevent the postoperative worsening of macular edema and may improve the final visual outcome without affecting safety.

In summary, eyes with a history of DME treatment and/or DME immediately prior to cataract surgery are at higher risk for developing central-involved macular edema 16 weeks after the cataract extraction, and intravitreal ranibizumab injection at the time of cataract surgery is effective in preventing postoperative macular edema in patients with cataract and stable diabetic retinopathy.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....