Purchase this article with an account.
J. F. Solus, H. A. Quigley, H. D. Jampel; Bleb Appearance After Fornix-Based vs. Limbus-Based Trabeculectomy. Invest. Ophthalmol. Vis. Sci. 2010;51(13):628.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To compare trabeculectomy bleb appearance after fornix-based or limbus-based conjunctival closure.
Wilmer Institute’s billing database had 1745 patients who underwent trabeculectomy from January, 1999 to October, 2008. Of these, 759 had one or two trabeculectomies that were not combined with another operation and had been performed by one of 2 glaucoma specialists. The type of closure was not selected randomly, most limbus cases performed from 1999-2004 and most fornix cases from 2005 to the present. Sixty-four percent (487/759) of patients underwent chart review and 425 eyes without subsequent surgery were directly examined and quantitatively graded using the Indiana Bleb Grading System. Not included were persons who were unreachable (197; 26%), refused consent (44; 6%), or deceased (31; 4%). Mean age and trabeculectomy type (fornix or limbus flap) did not differ in bleb-graded compared to all subjects (p > 0.06).
The grading system rates height, extent, vascularity and leak, on scales with 3 to 5 levels. Interobserver agreement between 2 physicians in 7 eyes masked to the other’s grading had 18 at identical levels (64%), 10 different by one level (36%), and none different by ≥ 2 levels. Surgeon 2 graded the same 18 eyes (15 patients) at visits separated by >2 months, masked to first grading. Forty-eight levels were identical (67%), 23 differed by 1 level (32%), and 1 differed by 2 levels. In the initial data analysis, vascularity grade V0, indicating an avascular, extremely thin bleb, was 2.5 times more common after limbus-based surgery (47% vs 18% in fornix-based, p <0.0001). Limbus-based blebs were twice as likely to be graded medium or high (compared to low) as fornix-based blebs (p <0.0001). The majority of blebs were graded as no_mild vascularity and from 1-4 clock hours in extent (limbus and fornix not different). Previously undetected leaking blebs were found in 2 (0.9%) of fornix and 3 (1.4%) of limbus operations (p = 0.64).
Fornix-based closure as practiced by these surgeons was associated with fewer extremely thin, high blebs that may be linked to leakage and late infection. The findings will be adjusted for time since surgery and success and complication rates given with full chart review.
This PDF is available to Subscribers Only