Is Beta Radiation Better than 5 Flurouracil as an Adjunct for Trabeculectomy Surgery When Combined with Cataract Surgery? A Randomised Controlled Trial.
BACKGROUND
In an African setting surgery is generally accepted as the treatment of first choice for glaucoma. A problem with trabeculectomy surgery for the glaucomas is the frequent co-existence and exacerbation of cataract. We report a randomized controlled trial to compare the use of beta radiation with 5FU in combined cataract and glaucoma surgery.


METHODS
Consenting adults aged >40 years with glaucoma, an IOP>21mmHG and cataract were enrolled and randomised to receive either 1000cG β radiation application or sub-conjunctival 5fluorouracil (5FU) at the time of combined trabeculectomy and phaco-emulsification with lens implant surgery.


RESULTS
385 individuals were eligible for inclusion of whom 301 consented to inclusion in the study (one eye per patient). 150 were randomised to the 5FU arm and 151 received β radiation. In the 12 months following surgery there were 40 failures (IOP>21mmHg) in the 5FU arm and 34 failures in the beta arm. The hazard ratio for the beta radiation arm compared to the 5FU arm, adjusted for IOP at baseline, was 0.83 (95% c.i. 0.54 to 1.28; P = 0.40). The improvement from mean presenting visual acuities of 0.91 and 0.86 logMAR to 0.62 and 0.54 in the 5FU and beta arms respectively was comparable between groups (P = 0.4 adjusting for baseline VA). Incidence of complications did not differ between the two groups.


CONCLUSIONS
This study highlights several important issues in the quest for a therapeutic strategy for the glaucomas in an African context. Firstly, there is no evidence of an important difference between the use of 5FU and beta radiation as an anti-metabolite in phacotrabeculectomy. Secondly phacotrabeculectomy is a successful operation that improves visual acuity as well as controlling IOP in a majority of patients. Although the success of trabeculectomy in lowering IOP is reduced when combined with phacoemulsification compared with trabeculectomy alone, this finding has to be set against the possible need for subsequent cataract surgery following trabeculectomy alone, which represents a second trip and expense for the patient and results in 10-61% failure of the trabeculectomy at one year post-cataract surgery.


BACKGROUND
ISRCTN Registry ISRCTN36436933.
Department of Ophthalmology, Comprehensive Community Based Rehabilitation Hospital in Tanzania (CCBRT), Dar Es Salaam, Tanzania.
Kazim
K
Dhalla
Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom.
Simon
S
Cousens
International Centre for Eye Health, London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom.
Richard
R
Bowman
Department of Ophthalmology, Comprehensive Community Based Rehabilitation Hospital in Tanzania (CCBRT), Dar Es Salaam, Tanzania.
Mark
M
Wood
Institute of Ophthalmology, University College of London, London, United Kingdom.
Ian
http://orcid.org/0000-0002-5453-0635
I
Murdoch
D000368:Aged; D001610:Beta Particles / Q000627:therapeutic use*; D002387:Cataract Extraction / Q000009:adverse effects; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D015814:Ocular Hypotension / Q000150:complications / Q000503:physiopathology; D018918:Phacoemulsification; D011183:Postoperative Complications / Q000209:etiology; D018714:Radiotherapy, Adjuvant; D016019:Survival Analysis; D014130:Trabeculectomy / Q000009:adverse effects; D016896:Treatment Outcome; D014792:Visual Acuity
D005472:Fluorouracil