Corneal decompensation following bleb needling with 0.01% mitomycin C: a case study

Rescue of failing or failed trabeculectomy blebs with slit-lamp needling and adjunctive mitomycin C in Indian eyes

Purpose:

The aim of this study is to investigate the efficacy and safety of needling-revision augmented with a high dose of mitomycin C (MMC) in failing or failed blebs after trabeculectomy in Indian eyes.

Methods:

Prospective, noncomparative, interventional study. All patients (>18 years) who had raised intraocular pressure (IOP) following trabeculectomy (>6 weeks and <2 years), who had a flat bleb, bleb encapsulation, and/or required antiglaucoma medication (AGM) for IOP control were eligible for inclusion. MMC was injected subconjunctivally at least ½ hour before the needling procedure was carried out at the slit lamp in the outpatient's clinic.

Results:

Thirty-nine eyes of 38 patients were included. The median follow-up was 20 months and time interval between trabeculectomy and needle revision was 113 days. Initially, in all cases, aqueous flow was re-established with a raised bleb; 7 eyes required repeat needling. IOP decreased from median 24 mmHg (Q1 21, Q3 27, interquartile range [IQR] 6, range 18–35) preneedling to median 14 mmHg (Q1 10, Q3 16, IQR 6, range 6–18) postneedling at last follow-up (P < 0.0001, 95% confidence interval [CI]: 8.2–13.0). The use of AGM reduced from median 1 (Q1 0, Q3 3, IQR 3, range 0–4) preneedling to median 0 postneedling (P < 0.0001, 95% CI: 1–2). Complete success was seen in 28 eyes (71.8%, 95% CI: 71.1%–96.4%); another 5 eyes (12.8%) were controlled with AGM (qualified success) with overall success of 84.6%. Most complications were transient in nature with resolution within 1 week. One patient developed hypotony, and another developed a late bleb leak.

Conclusion:

Needling revision augmented with high-dose MMC, at the slit lamp, effectively rescues failing or failed filtration, and appears to be safe.

Intraoperative Optical Coherence Tomography Guided Bleb Needling

Two patients with history of trabeculectomy presented with uncontrolled intraocular pressure (IOP) postoperatively. The first patient had a flat and vasularized bleb 10 weeks after the surgery, and the second subject developed encapsulated bleb 3 months postoperatively. Both patients were taken to the operating room and intraoperative optical coherence tomography (OCT) guided bleb needling was performed to restore aqueous egress into the subconjunctival space. Postoperatively, IOP of the operated eyes ranged 14-18 mmHg at week 6 and month 3. None of the eyes had any intraoperative or postoperative complications. This novel application of the intraoperative OCT for bleb needling facilitates precision surgery under direct visualization and reduces the risk of complications.