Six patients, each with one eye that had previously undergone circular buckling surgery for the repair of retinal detachment before or followed by cataract extraction with or without intraocular lens implantation, underwent trabeculectomy with 5-fluorouracil (5-FU) for intractable glaucoma. Surgery was done through scarred subconjunctival tissues that were excised partially. The total doses of 5-FU ranged from 65 to 100mg (mean +/- standard deviation, 84.2 +/- 13.2mg) Eight to 47 months later, intraocular pressures were 18mmHg in five eyes, two of which were not receiving hypotensive medications. In the sixth eye, the intraocular pressure was 26mmHg with maximum hypotensive treatment. Intraocular pressures in the six eyes were significantly lower postoperatively than preoperatively (P < .05). This preliminary study suggests that filtering surgery with 5-FU may be beneficial after intraocular operations even in eyes where it is done through postoperative scarred subconjunctival tissues.