Tugrul Altan, MD, Ziya Kapran, MD, Zerrin Bayraktar, MD, Nur Acar, MD, Yaprak B. Unver, MD, Mehmet Cakir, MD

Purpose:

To determine the effect of pars plana vitrectomy on rubeosis iridis (RI) and intraocular pressure and to evaluate the risk factors for the development of RI and glaucoma in diabetic eyes.

Methods:

201 eyes of 201 patients that underwent pars plana vitrectomy for the complications due to proliferative diabetic retinopathy were included in the study. Mean age was 56,79±12,22. The duration of the diabetes was 13,75±7,05 years. 38 patients had type 1,163 patients had type 2 diabetes. Patients were followed for 7,51±7,36 months.

Results:

Mean preoperative intraocular pressure (IOP) was 14,81±3,59mmHg, and only 7 patients had IOP levels above 22mmHg. 22 of the 201 eyes (10.9%) patients had RI preoperatively. No patient had neovascular glaucoma preoperatively. The rate of RI didn’t change significantly throughout the follow-up period (p>0.05). Mean IOPs were stable in the whole group during follow-up with a nonsignificant drop at the 3rd month. IOPs of the rubeotic eyes did not change significantly throughout the follow-up period. Rubeotic eyes had significantly higher IOPs than the nonrubeotic eyes preoperatively (p=0,03). At the postoperative period this difference was detected only at the 1 month visit, and there was no significant difference in the IOPs of the rubeotic and nonrubeotic patients through the rest of the follow-up period. But at the 1 year visit eyes with RI had a tendency to either hypotony or higher IOPs.

Conclusion:

PPV is effective in preserving normal IOPs in rubeotic patients in early and midterm. But the long-term follow-up is needed for detecting and treating harmful effects of hypotony and neovascular glaucoma in these high risk patients.

Take-home message:

There is an early drop in IOPs in eyes with RI after PPV and hypotony or glaucoma may develop later.