Management of chronic hypotony following trabeculectomy with mitomycin C

Iatrogenic Bleb Formation and Hypotony Maculopathy Following Pterygium Surgery with Mitomycin-C

Purpose:

To report a case of late iatrogenic bleb formation and hypotony maculopathy after pterygium surgery applying Mitomycin C (MMC).

Case Report:

A 66-year-old man presented with an elevated, bleb-like, fluid-filled, cystic lesion on the nasal sclera of the right eye. The patient had undergone pterygium surgery with a combination of conjunctival autograft and adjuvant intraoperative MMC 0.02% four years before. The sclera seemed fistulized at the site of surgery and a thin layer of conjunctiva completely covered the lesion. A scleral patch graft was secured over the fistula with sutures, followed by excision of the thinned, avascular conjunctiva and advancement of the healthy adjacent conjunctiva to cover the patch graft. One month later, a small bleb re-appeared adjacent to the scleral patch graft and IOP was 2 mmHg. Argon-laser treatment of the bleb was tried to induce scarring and reduction of bleb size, and was highly effective. After one week, IOP was increased to 8 mmHg. The clinical features remained stable four months after initial presentation.

Conclusion:

Pterygium surgery using adjuvant MMC may result in late iatrogenic bleb formation and hypotony maculopathy. This complication can be successfully corrected surgically using a scleral patch graft combined with argon laser treatment over the inadvertent bleb.

Surgical repair of leaking filtering blebs

PURPOSE

To report the surgical management of leaking filtering blebs occurring after blebitis or persistent hypotony.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Twenty-two eyes of 20 patients with late bleb leak, blebitis or endophthalmitis, hypotony maculopathy, or bleb dysesthesia on presentation to the glaucoma service who required surgical bleb revision from 1990 through 1999.

INTERVENTION

Pedicle flap, partial excision, and advancement or free conjunctival autologous graft techniques for surgical bleb revision. Type of bleb revision was dependent on the dimensions of the bleb and quality of surrounding conjunctiva.

MAIN OUTCOME MEASURES

Preoperative and postoperative intraocular pressure (IOP), status of bleb leak, reoperation for glaucoma, or requirement for postrevision glaucoma medical therapy, with success defined as the need for two or fewer glaucoma medications after revision.

RESULTS

Eighty-six percent (19/22) of eyes that underwent surgical bleb revision had resolution of leak and IOP control using two or fewer medications after one or more bleb revisions. The preoperative IOP (mean +/- standard deviation) was 3.7 +/- 2.6 mmHg (range, 0-8 mmHg). After an average follow-up of 21 months (range, 8-108 months), the IOP was 11.0 +/- 4.4 mmHg for patients taking 0.6 +/- 1.0 glaucoma medications. Eighteen percent (4/22) of eyes required two or more bleb revisions. In one eye, an IOP spike of 36 mmHg developed after revision, which required laser suture lysis on two occasions before the IOP was significantly lowered. The three failures were: one eye that required three or more medications for IOP control, a patient whose eye had a persistent leak after revision and who was not mentally competent to undergo repeat revision, and one eye that required combined glaucoma and cataract surgery after revision.

CONCLUSIONS

Surgical bleb revision has a high success rate of closing late bleb leaks, maintaining glaucoma control, and preserving vision, with few postoperative complications. The appropriate surgical procedure for revision must be based on the individual clinical situation and can result in successful bleb revision.