Efficacy of vitrectomy combined with and without cataract surgery for diabetic macular edema: one-year follow-up multi-center study in Japan.

PURPOSE

To evaluate the efficacy of vitrectomy, with and without cataract surgery, for diabetic macular edema (DME) in Japan.

METHOD

This retrospective study was conducted at 22 sites in Japan and enrolled patients who underwent vitrectomy either without (VIT group) or with (VIT + CS group) cataract surgery. Central retinal thickness (CRT) and best-corrected visual acuity (BCVA) were measured before surgery and at 1, 3, 6, and 12 months after surgery.

RESULTS

A total of 722 patients with DME (482 in the VIT + CS group and 240 in the VIT group) were enrolled. CRT significantly decreased after 1 month and continued thereafter in both groups. BCVA significantly improved at 1 month in the VIT + CS group and at 6 months in the VIT group. In both groups, regardless of epiretinal membrane removal, CRT and BCVA significantly improved, with no additional benefit from concomitant internal limiting membrane peeling. The change in BCVA was significantly correlated with the change in CRT during 6 months postoperatively in all patients and in the VIT group. Patients with worse preoperative visual acuity had a higher likelihood of improved BCVA at 6 and 12 months after surgery. No significant difference in BCVA was observed before and after surgery in patients with a preoperative visual acuity of 20/40 or better. However, in patients with a visual acuity of 20/50 or worse, BCVA significantly improved 1 month after surgery.

CONCLUSION

Vitrectomy is anatomically and functionally effective for DME, and combined cataract surgery is beneficial in DME cases with cataracts. Patients with poor preoperative BCVA improved, while those with good vision maintained it. However, better preoperative vision increased the risk of postoperative deterioration, underscoring the need for careful evaluation of surgical indications.

KEY MESSAGES

What is known In vitrectomy for diabetic macular edema (DME), DRCR.net showed that 13-31% of patients experience decreased vision despite reduced edema, leaving the efficacy of vitrectomy uncertain. What is new Our multicenter study demonstrated that vitrectomy with and without cataract surgery was effective in improving central retinal thickness and visual acuity in the patients with DME. Better preoperative visual acuity increased the risk of postoperative decline, and thus the need for careful evaluation of surgical indications.