Trabeculectomy augmented with mitomycin C application under the scleral flap.
OBJECTIVE
The authors investigated the safety and intraocular pressure (IOP) lowering effectiveness of trabeculectomy augmented with mitomycin C application beneath the scleral flap, and assessed the influence of preoperative risk factors on the surgical outcome.


METHODS
A retrospective study of 72 consecutive high risk eyes undergoing trabeculectomy with adjunctive mitomycin C (0.2 mg/ml) applied under the scleral flap for 5 minutes was performed. Each eye was ascribed a score based on the number of preoperative risk factors, and categorised into one of three risk factor groups. Success was described as unqualified where IOP was < or = 21 mm Hg without medication and qualified where antiglaucomatous therapy was required to maintain it at such a level. A life table analysis of IOP control was calculated.


RESULTS
The mean IOP (SD) fell from a preoperative level of 28.4 (6.9) to a level of 16.63 (8.06) mm Hg at the last follow up (paired Student's t test: p < 0.0001). Fifty two eyes (72%) were classed as unqualified successes. The survival rates did not differ significantly between different risk factor groups (log rank test: chi 2 = 0.967, p > 0.1). The incidence of postoperative complications compared favourably with reports of mitomycin C application between Tenon's capsule and the undissected scleral bed.


CONCLUSIONS
The results illustrate that mitomycin C applied beneath the scleral flap during trabeculectomy in high risk eyes is associated with a success rate comparable to other modes of application. The incidence of potentially serious complications such as conjunctival wound leak and prolonged hypotony was lower than previously published data reporting sub-Tenon's administration of mitomycin C. The number and nature of preoperative risk factors do not appear to influence the surgical outcome. A possible mechanism of action is proposed.
Beatty
S
S
Birmingham and Midland Eye Centre, City Hospital NHS Trust.
Potamitis
T
T
Kheterpal
S
S
O'Neill
E C
EC
D000328:Adult; D003131:Combined Modality Therapy; D005500:Follow-Up Studies; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure; D015993:Life Tables; D008875:Middle Aged; D016685:Mitomycin / Q000008:administration & dosage* / Q000627:therapeutic use; D019384:Nucleic Acid Synthesis Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use; D012189:Retrospective Studies; D012307:Risk Factors; D012590:Sclera; D014130:Trabeculectomy / Q000379:methods*; D016896:Treatment Outcome; D014792:Visual Acuity
D019384:Nucleic Acid Synthesis Inhibitors; D016685:Mitomycin