Capsule excision and Ologen implantation for revision after glaucoma drainage device surgery.

Background: There is little information available about surgical management after failed glaucoma drainage device (GDD) surgery. We present the outcome of capsule excision after failed GDD surgery compared to capsule excision with additional use of a biodegradable implant (Ologen, version 2) as a placeholder.

Methods: In an observational comparative case series of 19 patients undergoing excision of the GDD capsule, ten prospectively observed consecutive patients were treated by excision of the capsule, topical mitomycin C application, and implantation of an 10 x 10 x 2 mm-sized Ologen implant (group A) while 9 retrospectively observed consecutive patients were treated by excision of the capsule and topical mitomycin C application alone (group B).

Results: Mean preoperative IOP was 29.4 mmHg for group A and 27.6 mmHg for group B, while mean postoperative IOP at the last follow-up (mean follow-up 11.2 (group A) and 8.6 (group B) months) was 17.3 mmHg for group A and 19.3 mmHg for group B (p > 0.05). Follow-up of the two groups demonstrated a significant difference in success rate (log-rank test, p = 0.04) in favor of group A. No further pressure-reducing surgery was necessary in any of the patients in group A, but it was needed in three of nine patients in group B.

Conclusions: Although our study has the limitations of small sample size and observational study design, it shows that further investigation is warranted into the potential of Ologen in revision surgery after GDD implantation.