Evaluation of Vitrectomy for Diabetic Macular Edema

Subject-level Inclusion Criteria

To be eligible, the following inclusion criteria (1-3) must be met:

• Age >= 18 years
• Diagnosis of diabetes mellitus (type 1 or type 2)
• Able and willing to provide informed consent.

Subject-level Exclusion Criteria

A patient is not eligible if any of the following exclusion criteria (4-6) are present:

• A condition that, in the opinion of the investigator, would preclude participation in the study (e.g., unstable medical status including blood pressure and glycemic control).
• Patient is expecting to move out of the area of the clinical center to an area not covered by another clinical center during the first year of the study.
• Blood pressure >180/110 (systolic above 180 OR diastolic above 110).

Study Eye Criteria

To be a study eye, all of the inclusion criteria (a-e) and none of the exclusion criteria (f-m) listed below must be met. A patient can have only one study eye. If both eyes are eligible and undergoing vitrectomy, the first eye having surgery will be the study eye.

The eligibility criteria for a study eye are as follows:

Inclusion

• Vitrectomy being performed as treatment for DME.
• E-ETDRS visual acuity 20/800 or better (E-ETDRS visual acuity score >= 3 letters).
• Definite retinal thickening due to diabetic macular edema based on clinical exam involving the center of the macula.
• Presence of vitreomacular traction associated with macular edema OR edema is felt to be too diffuse to respond to focal or grid laser OR edema judged to be inadequately responsive to previous treatment(s) and unlikely to benefit from further focal photocoagulation.
• Media clarity, pupillary dilation, and patient cooperation sufficient for adequate fundus photographs.

Exclusion

• Macular edema is considered to be due to a cause other than diabetic macular edema.
• An ocular condition is present such that, in the opinion of the investigator, visual acuity would not improve from resolution of macular edema (e.g., foveal atrophy, pigmentary abnormalities, subfoveal hard exudates, fibrous metaplasia, nonretinal condition).
• An ocular condition is present (other than diabetes) that, in the opinion of the investigator, might affect macular edema or alter visual acuity during the course of the study (e.g., vein occlusion, uveitis or other ocular inflammatory disease, neovascular glaucoma, post-surgical cystoid macular edema, etc.).
• History of retinal macular photocoagulation, intravitreal corticosteroids, or other treatment for DME within 3.5 months prior to enrollment.
• History of peripheral scatter photocoagulation within 4 months prior to enrollment or anticipated need within the 4 months following enrollment.
• History of prior pars plana vitrectomy.
• History of major ocular surgery (including cataract extraction, scleral buckle, any intraocular surgery, etc.) within prior 6 months or anticipated within the next 6 months following enrollment.
• History of YAG capsulotomy performed within 2 months prior to enrollment.