Tip of the Month
Publishing date: November 2013
The Science behind the Tip
Trabeculectomy surgery is a recognised risk factor for the subsequent development of cataract. Phacoemulsification with intraocular lens implantation performed in the presence of a functioning trabeculectomy bleb has an adverse effect on IOP control and can lead to failure of the trabeculectomy bleb (1). Casson et al reported that 18% of patients who had a functioning bleb had commenced or were using additional glaucoma medication 2 years after cataract surgery (2).
The risk of trabeculectomy failure is increased if the time between trabeculectomy and cataract surgery is short; with an adjusted declining hazard ratio of 3.00 (95% CI 1.11 - 8.14) at 6 months and 1.32 (95% Cl 1.02 -1.69) at 2 years (3). The use of subconjunctival injections of 5-flurouracil after cataract surgery in these circumstances does not appear to reduce the risk of trabeculectomy failure (4).
Contributor: John Salmon, Oxford
1. Rebolleda G, Munoz-Negrete FJ. Phacoemulsification in eyes with functioning blebs: a prospective studly. Ophthalmology 2002; 109:2248-2255.
2. Casson R, Rahman R, Salmon J.F. Phacoemulsification with intraocular lens implantation after trabeculectomy. J Glaucoma 2002; 11:429-433.
3. Husain R, Liang S, Foster PJ et al Cataract surgery after trabeculectomy: the effect on trabeculectomy function. Arch Ophthalmol 2012; 130: 165-170.
4. Shahid H, Salmon JF. Use of 5-fluorouracil injections to reduce the risk of trabeculectomy bleb failure after cataract surgery. J Ocular Pharm & Therapeutics 2010; 26:119-123.
Tip Reviewer: Roger Hitchings
Tip Editors: John Salmon and John Thygesen