Morphologic classification of filtering blebs after glaucoma filtration surgery: the Indiana Bleb Appearance Grading Scale.
OBJECTIVE
To establish a new classification system for filtering blebs according to clinical morphologic parameters. The purpose of this classification system is to provide a uniform and objective assessment of bleb appearance and establish a framework system through which outcomes of filtration surgery may be better correlated to clinical morphology.


METHODS
The Indiana Bleb Appearance Grading Scale contains a set of photographic standards illustrating a range of filtering bleb morphology selected from the slide library of the Glaucoma Service at the Indiana University Department of Ophthalmology. These standards consist of slit lamp images for grading bleb height, extent, vascularity, and leakage with the Seidel test. For grading, the morphologic appearance of the filtration bleb is assessed relative to the standard images for the 4 parameters and scored accordingly. Fifty-one clinical bleb photographs were evaluated and scored by 3 glaucoma subspecialists in a masked fashion according to the scale.


RESULTS
For all of the grading scales, high interobserver agreement was found using the scale to classify the appearance of filtering blebs (height +0.76; extent +0.78; vascularity +0.90, interclass correlation coefficient for consistency using a 2-way mixed effect model).


CONCLUSIONS
The Indiana Bleb Appearance Grading Scale is a simple, reproducible, yet comprehensive system for classifying the morphologic slit lamp appearance of filtration blebs.
Cantor
Louis B
LB
Department of Ophthalmology, Indiana University School of Medicine, 702 Rotary Circle, Indianapolis, IN, USA. lcantor@iupui.edu
Mantravadi
Anand
A
WuDunn
Darrell
D
Swamynathan
Kala
K
Cortes
Arnold
A
D018463:Filtering Surgery; D005901:Glaucoma / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D011184:Postoperative Period; D016896:Treatment Outcome