Abstract
Purpose :
To investigate pre-operative risk factors including antimetabolite choice with regard to bleb morphology in glaucoma patients undergoing trabeculectomy over an 11-year period. The main aim was to identify potential risk factors for the development of non-ideal thin cystic (or cystic-in-part) blebs, these being associated with a greater risk of hypotony or endophthalmitis.
Methods :
Retrospective, single centre, observational cohort study of 631 consecutive eyes which had undergone trabeculectomy with a mean follow-up period of more than 5 years. For each case, final bleb morphology was recorded and correlated against the antimetabolite used using a Chi-squared test. Other potential risk factors were analysed using multinominal and ordinal logistical regression analyses to identify factors that could contribute to the development of adverse bleb morphology.
Results :
The mean follow-up period for the entire cohort was 65.5±35.7 months. The mean IOP for all eyes reduced from 23.4±6.2 mmHg pre-operatively to 12±4.2 mmHg. When 5-Fluorouracil was used (n=195), 24% of patients formed cystic blebs whereas with Mitomycin-C (n=263) only 12% formed cystic blebs (p=0). Potential confounding factors including age, gender, race, primary glaucoma diagnosis, pre- or post-operative IOP, long-term duration of pre-operative anti-glaucoma medications, surgical grade and history of previous surgery did not correlate with final bleb morphology. Continuity of care by the operating surgeon correlated significantly with non-cystic bleb morphology (chi-squared=13.8, p=0). The number of needlings performed following surgery correlated significantly with ideal bleb morphology (chi-squared=6, p=0.015). Afro-Carribean patients were more likely to form a cystic bleb (chi-squared=5.22, p=0.022). Other potential risk factors were not significant. The number of pre-operative medication used correlated significantly with adverse bleb morphology (chi-squared=19, p=0.004).
Conclusions :
Modern use of Mitomycin-C may be preferable to 5-Fluorouracil as an adjunctive antimetabolite used at the time of trabeculectomy with respect to preferable final bleb morphology. Pre-operative number of topical medications as well as other risk factors (including post-operative bleb needling procedures and continuity of care by the operating surgeon) may also play a role in determining final bleb morphology.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.