A randomised, prospective study comparing trabeculectomy with viscocanalostomy with adjunctive antimetabolite usage for the management of open angle glaucoma uncontrolled by medical therapy.
OBJECTIVE
To compare trabeculectomy with viscocanalostomy augmented with adjunctive antimetabolite use for the control of intraocular pressure (IOP) in open angle glaucoma (OAG).


METHODS
45 patients (50 eyes) with uncontrolled OAG were randomised to either trabeculectomy (25 eyes) or a viscocanalostomy technique (25 eyes). Preoperatively, all eyes were graded in terms of risk factors for drainage failure and were given intraoperative antimetabolites (5-fluorouracil 25 mg/ml (5-FU), mitomycin C (MMC) 0.2 mg/ml and 0.4 mg/ml) according to a standard protocol.


RESULTS
There were no significant differences between the groups in age, sex, type of OAG, preoperative medications, risk factors for drainage failure, and preoperative IOP. Mean follow up was 20 months (range 3-24 months). It was 12 months or longer in all eyes, except two lost to follow up at 3 months. At 12 months, complete success (IOP<21 mm Hg without antiglaucoma medications) was seen in 91% of eyes undergoing trabeculectomy, but in only 60% of eyes undergoing viscocanalostomy (p<0.02). Similarly, at the last follow up visit (mean 20 months) complete success was seen in 68% of eyes undergoing trabeculectomy and 34% with viscocanalostomy (p<0.05). In terms of qualified success (IOP<21 mm Hg with or without glaucoma medications) and mean IOP measurements postoperatively there were no difference between the groups, although the mean number of antiglaucomatous medications required postoperatively was less with trabeculectomy (0.39) than viscocanalostomy (1.04) (p<0.05). Needling procedures were more commonly required after trabeculectomy (p<0.02). YAG goniotomy was required in three eyes (13%) after viscocanalostomy. Early transient complications such as anterior chamber shallowing and encysted blebs were more common in the trabeculectomy group (p<0.05). Late postoperative cataract formation was similar between the two groups.


CONCLUSIONS
In terms of complete success and number of antiglaucomatous medications required postoperatively, IOP control appears to be better with trabeculectomy. Viscocanalostomy is associated with fewer early transient postoperative complications.
O'Brart
D P S
DP
Department of Ophthalmology, St Thomas's Hospital, London SE1 7EH, UK. davidobrart@aol.com
Shiew
M
M
Edmunds
B
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000963:Antimetabolites / Q000627:therapeutic use*; D001768:Blister / Q000209:etiology; D002386:Cataract / Q000209:etiology; D005260:Female; D018463:Filtering Surgery / Q000379:methods*; D005472:Fluorouracil / Q000627:therapeutic use; D005902:Glaucoma, Open-Angle / Q000188:drug therapy / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D016685:Mitomycin / Q000627:therapeutic use; D011182:Postoperative Care / Q000379:methods; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies; D012599:Sclerostomy / Q000379:methods; D014130:Trabeculectomy / Q000379:methods; D016896:Treatment Outcome
D000963:Antimetabolites; D016685:Mitomycin; D005472:Fluorouracil