Late-onset, bleb-associated endophthalmitis following glaucoma filtering surgery with or without antifibrotic agents

The use of adjunctive antimetabolites such as 5-fluorouracil (5-FU) and mitomycin C (MMC) in trabeculectomy has caused an increased concern as to the risk of bleb-associated endophthalmitis. In this study, we compared the incidence of this complication between different methods of adjunctive treatment in glaucoma filtering surgery. Records of 15 cases of late-onset, bleb-associated endophthalmitis which were admitted to the Ophthalmology Department, Hadassah University Hospital, between January 1980 and December 1997 were retrospectively studied. These patients had endophthalmitis at least two months following glaucoma filtering surgery. Bleb-associated endophthalmitis occurred in 2 eyes following filtering surgery with no antifibrotic agent, in 6 eyes following trabeculectomy with 5-FU, and in 7 eyes that underwent trabeculectomy with intraoperative MMC. The mean time from surgery to endophthalmitis following 5-FU was 25.0+/-22.0 months (range 3 to 56 months), and 11.3+/-5.4 months (range 4 to 18 months) following the use of MMC. The estimated cumulative incidences of bleb-associated endophthalmitis in superior blebs at 24 months following surgery were 0.3% for surgeries without antifibrotic agents, 0.8% for trabeculectomies with postoperative 5-FU, and 1.3% for trabeculectomies with intraoperative MMC. No significant differences were demonstrated between the survival distributions of filtering procedures performed with any of the three techniques (p = 0.166, Log-rank test). Most of the cases following 5-FU or MMC appeared within 18 months following trabeculectomy. The visual outcome of most of the eyes was poor. Antifibrotic agents are not associated with a higher risk for late-onset, bleb-associated endophthalmitis. A high rate of alertness is warranted for diagnosis of early signs of infection following glaucoma filtering surgery.