New surgical approach under investigation for chronic cystoid DME

Vitrectomy with drainage of cystoid spaces is being evaluated as a new surgical treatment for patients with chronic cystoid diabetic macular edema (DME) who are unresponsive to other interventions and who have minimal or no leakage on fluorescein angiography and good foveal capillary perfusion, said Hilel Lewis, MD, director, Cole Eye Institute, Cleveland Clinic, Cleveland, OH.

Dr. Lewis described the surgery, preliminary results and the possible mechanism for its promise. The procedure involves making a superficial incision into the cysts and using instrumentation to remove the accumulated intraretinal fluid. Initial results from 12 patients with prominent cystoid changes on OCT suggested that the procedure might decrease or resolve the DME and stabilize or improve the vision. None of the patients in that series experienced any worsening of their DME and mean visual acuity for the group improved from 20/220 to 20/123. Two-thirds of the patients experienced a 2-line or greater gain.

The potential benefit may be explained by the understanding that in eyes with chronic DME, there can be damage to the retinal pigment epithelium that interferes with its ability to reabsorb the fluid into the choriocapillaris.

"Even if the retinal vasculature is re-established by photocoagulation or by treatment with pharmacotherapy, the macular edema persists and is not able to reabsorb the fluid," Dr. Lewis said. "In this setting, surgical fluid removal could potentially be beneficial."