The investigators aim to evaluate how different timing of anti-VEGF intravitreous injections affect visual acuity (BCVA) in patients with diabetic macular edema who are undergoing cataract surgery; and to evaluate how different timing of anti-VEGF intravitreous affect OCT CSF thickness and total number of postoperative injections in patients with diabetic macular edema who are undergoing cataract surgery.

Cataract is very common in diabetic patients and can lead to significant vision loss and disability without medical intervention. Diabetic patients, particularly those with diabetic macular edema (DME), experience poorer visual outcomes after undergoing cataract surgery compared to non-diabetics. An increased risk in the development of post-operative cystoid macular edema and exacerbation of baseline DME is reported and this poses a significant challenge in managing concomitant DME and visually-significant cataracts.

Goals of the study are to evaluate how different timing of anti-VEGF intravitreous injections (before operation, intra-operation or after-operation) affect visual acuity (BCVA) in patients with persistent diabetic macular edema who are undergoing cataract surgery; and to evaluate how different timing of anti-VEGF intravitreous injections affect OCT CSF thickness and total number of postoperative injections in patients with diabetic macular edema who are undergoing cataract surgery.

Inclusion Criteria:

Adults over age 18 with diabetes mellitus, diabetic macular edema and visually significant cataracts planning to undergo cataract surgery

Exclusion Criteria:

Patients who have undergone panretinal photocoagulation (PRP) in prior 4 months or an ocular condition (other than cataract and DME) that might affect visual acuity during course of study.

Patients with history of vitrectomy. Patients with neovascular glaucoma