Email updates

Keep up to date with the latest news and content from BMC Ophthalmology and BioMed Central.

Open Access Research article

Is post-trabeculectomy hypotony a risk factor for subsequent failure? A case control study

Sarah E Benson12, Kaveri Mandal1, Catey V Bunce2 and Scott G Fraser13*

Author Affiliations

1 Sunderland Eye Infirmary, Queen Alexandra Road, Sunderland, SR2 9HP, UK

2 Moorfields Eye Hospital, City Road, London, EC1V 2PD, UK

3 School of Health, Natural and Social Sciences, University of Sunderland, UK

For all author emails, please log on.

BMC Ophthalmology 2005, 5:7  doi:10.1186/1471-2415-5-7

Published: 5 April 2005

Abstract

Background

Ocular hypotony results in an increased break down of the blood-aqueous barrier and an increase in inflammatory mediator release. We postulate that this release may lead to an increased risk of trabeculectomy failure through increased bleb scarring. This study was designed to try to address the question if hypotony within one month of trabeculectomy for Primary Open Angle Glaucoma (POAG), is a risk factor for future failure of the filter.

Methods

We performed a retrospective, case notes review, of patients who underwent trabeculectomy for POAG between Jan 1995 and Jan 1996 at our hospital. We identified those with postoperative hypotony within 1 month of surgery. Hypotony was defined as an intraocular pressure (IOP) < 8 mmHg or an IOP of less than 10 mmHg with choroidal detachment or a shallow anterior chamber. We compared the survival times of the surgery in this group with a control group (who did not suffer hypotony as described above), over a 5 year period. Failure of trabeculectomy was defined as IOP > 21 mmHg, or commencement of topical antihypertensives or repeat surgery.

Results

97 cases matched our inclusion criteria, of these 38 (39%) experienced hypotony within 1 month of surgery. We compared the survival times in those patients who developed hypotony with those who did not using the log-rank test. This data provided evidence of a difference (P = 0.0492) with patients in the hypotony group failing more rapidly than the control group.

Conclusion

Early post-trabeculectomy hypotony (within 1 month) is associated with reduced survival time of blebs.