[5-fluorouracil in the treatment of postoperative glaucoma]

Standard filtering surgery in postoperative glaucoma in aphakic and pseudophakic eyes and eyes after failed filtering surgery is successful in 50% cases. The main cause of failure filtering surgery is scarring of the filtering bleb-fibroblastic proliferation at the subconjunctival episcleral interface [1, 2]. The use of antimetabolites such as 5-fluorouracil and Mitomycin C inhibits fibroblast proliferation and increases the success rate of filtering surgery, especially in postoperative glaucoma [3-6]. The exact dosage and frequency of administration to maximize success and minimize complications of treatment has not yet been determined [7].

Fifteen patients (15 eyes) with medically uncontrolled postoperative glaucomas were included in the study. Clinical data are summarised in Table 1. All patients after standard trabeculectomy received 5 mg of 0.3 ml 5-fluorouracil subconjunctivally each day for 7 days. The mean 5-fluorouracil dose was 25.1 mg. Topical corticosteroid and cycloplegic eye drops were also instilled in all 15 eyes for 4 weeks after surgery.

Successful control of IOP was achieved after a 5-fluorouracil filtering procedure in 13 of 15 eyes (86.6%), with a mean follow-up of 11.4 months. Two patients (13.4%) with uncontrolled glaucoma required cyclokryocoagulation in addition to antiglaucoma medications. Transscleral fibrosa and internal occlusive membrane were the primary cause of failure of filtration fistulas. Only one patient in the group of successful control of IOP required topical 0.5% Timolol (Table 1). Mean value of postoperative IOP was 13.53 mmHg. Most of the early complications such as corneal epitheliopathy, corneal epithelial defects and shallow anterior chamber, resolved without irreversible damage. Two eyes had transient maculopathy and choroidal detachment. There were no late complications, except progression of cataracta in one eye (Table 2).

Our success rate in 5-fluorouracil treatment in postoperative glaucoma was 86.6%. The results of Fluorouracil Filtering Surgery Study Group revealed failure in 28% of eyes with 5-fluorouracil treatment compared to 60% of eyes in standard group without fluorouracil. We achieved better results in shorter follow-up. Short term complications related to 5-fluorouracil treatment such as corneal epithelipathy, recovered well with time. Long term complications caused by thin and cystic blebs: endophthalmitis, iridocyclitis, late bleb leaks, bleb encapsulated, were not recorded in our series. By comparing the results reported here with those previously reported [8-10] it looks like that certain long term complications can be reduced by adjusting the dose according to the clinical response. Weinrab et al. [10] reported similar successful surgical outcomes in refractory glaucoma, but these results cannot be compared directly, because of likely differences in such factors, as are the indications of surgical criteria for selection of specific surgical procedures, surgical technique and postoperative care. Some clinical reports have shown that Mitomycin C contributes to the increased success of filtering surgery in high risk glaucoma [11, 12], but 5-fluorouracil is still the golden standard among other antimetabolites.