The effect of reducing the exposure time of mitomycin C in glaucoma filtering surgery.
BACKGROUND
The use of adjunctive intraoperative mitomycin C has considerably improved the success rate of glaucoma filtering surgery. However, the ideal concentration and exposure time of mitomycin C is unknown. The purpose of this study is to determine whether a satisfactory surgical outcome can be achieved with a lower incidence of adverse side effects by using a shorter exposure time of mitomycin C than has been recommended previously.


METHODS
Twenty-five eyes of 25 consecutive patients who were considered to be at high risk for surgical failure because of their age (< 55 years), previous failure of trabeculectomy, previous cataract surgery, or traumatic glaucoma received a single intraoperative application of mitomycin C (0.2 mg/ml for 2 minutes). They were case-matched with a group of 48 consecutive patients who received a single intraoperative application of mitomycin C (0.2 mg/ml for 5 minutes) by using age, race, type of refractory glaucoma, and preoperative intraocular pressure (IOP) as variables.


RESULTS
Eighteen months after surgery, 22 (88%) patients in the 2-minute group and 21 (84%) patients in the 5-minute group had an IOP less than 21 mmHg with or without treatment. No significant differences were found in the complication rate: in 2 (8%) of 25 eyes of the 2-minute group, chronic hypotony developed compared with 3 (12%) of 25 eyes in the 5-minute group. Hypotony-related maculopathy developed in one eye in the 5-minute group. A cystic bleb was found in 15 (60%) eyes in the 2-minute group compared with 19 (76%) eyes in the 5-minute group, although this difference was not statistically significant. Two (8%) eyes in the 2-minute group and one eye (4%) in the 5-minute group had a bleb-related infection. In one (4%) patient in each group, late severe endophthalmitis developed.


CONCLUSIONS
These results suggest that a 2-minute intraoperative application of 0.2 mg/ml mitomycin C is as effective as a 5-minute exposure, but the complication rate remains unaltered.
Department of Ophthalmology, Groote Schuur Hospital, Cape Town, South Africa.
G S
GS
Mégevand
J F
JF
Salmon
R P
RP
Scholtz
A D
AD
Murray
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D018463:Filtering Surgery; D005500:Follow-Up Studies; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure; D007430:Intraoperative Care; D008875:Middle Aged; D016685:Mitomycin / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D011183:Postoperative Complications; D011184:Postoperative Period; D012189:Retrospective Studies; D013997:Time Factors; D017211:Treatment Failure
D016685:Mitomycin