Sir,

We read with interest Anand and Wechsler’s recently published article on deep sclerectomy with mitomycin C1 and would like to congratulate the authors on their excellent outcomes. We have retrospectively analysed the long-term outcomes of trabeculectomies with selective 5-fluorouracil (5-FU) enhancement performed by a single district general hospital ophthalmologist (author APM) and would like to share our results as they are remarkably similar.

We performed trabeculectomies on 48 patients (53 eyes) attending a UK district general hospital and used 5-FU enhancement in 36% of the patients. Our entire cohort was caucasian and just 13% of it previously had cataract extraction. The mean preoperative intraocular pressure was 26.4 (SD 6.72) while by 12 months and 5 years postoperatively, the pressures had come down to 14.9 (SD 3.90) and 14.0 (SD 3.52), respectively. We defined success as intraocular pressure at the last follow-up appointment of ≤16 off all medication, which we achieved in 77.4% of our cohort.

During our mean follow-up period of 5.04 years, one patient developed endophthalmitis (1.9%), seven patients (13%) had postoperative choroidal effusions and five patients (9%) postop hyphaemas. In all, 34% of our cohort had early postop hyptony, all of which settled spontaneously and none led to hypotony maculopathy.

Like the authors, we have reservation about routine MMC enhancement of trabeculectomies in view of the reported increased risk of hyptony and endophthalmitis.2 We never made use of it in our cohort; 5-FU enhancement proved adequate. In tertiary centres with large numbers of patients at high risk of bleb failure, MMC enhancement is likely to be frequently necessary; but for the unselected patient attending a UK district general hospital, we would advocate caution in its use as the ‘default’ option in glaucoma surgery.

Deep sclerectomy with MMC enhancement appears safe and effective and produces similar results to trabeculectomy with low potency antimetabolite enhancement. In appropriately selected cases, we feel it should be a considered procedure where trabeculectomy and MMC carry potentially higher risks as concluded by Anand and Wechsler.