Aims To evaluate primary trabeculectomy with adjunctive mitomycin-C (MMC) in diabetic patients with primary open angle glaucoma (POAG).

Methods Patients with diabetes mellitus (DM) without retinopathy who had ≥6 months of postoperative follow-up were retrospectively compared with a control group selected from the pool of patients without DM matched case-by-case to the diabetic group by age, gender, race, preoperative intraocular pressure (IOP) and lens status. Surgical success was defined as IOP ≤15 and >5 mm Hg (± glaucoma medications) without complications or additional glaucoma surgery.

Results 41 eyes (29 patients) with DM and 81 eyes (64 patients) without DM were compared. Kaplan–Meier cumulative survival rates at 60 months were 57.8±9.3% (DM group) and 68.6±5.3% (control group), and the mean trabeculectomy survival times were 63 months (DM group, 95% CI 50.3 to 75.7) and 74.6 months (control group, 95% CI 67.1 to 82.1; p=0.095). Mean postoperative IOP of control group was statistically significant lower at 2-, 3-, 6- and 7-year follow-up visits (p<0.05). Rates of postoperative complications and additional glaucoma surgeries required were not different between the two groups.

Conclusions POAG patients with DM without retinopathy undergoing primary trabeculectomy with MMC do not achieve the same long-term IOP control and may have a lower long-term surgical survival rate compared with patients without DM.