Enhanced Glaucoma Staging System (GSS 2) for classifying functional damage in glaucoma.
OBJECTIVE
To introduce a new method, derived from the Glaucoma Staging System (GSS), for classifying glaucomatous visual field defects.


METHODS
Four sample groups composed respectively of 471 (sample #1), 128 (sample #2), 185 (sample #3), and 131 (sample #4) patients with either ocular hypertension or chronic glaucoma were considered. The GSS 2 uses both the MD and CPSD/CLV or PSD/LV perimetric indices to classify visual field defect in 6 stages and in 3 types (generalized, localized, and mixed). The formulas were determined using sample #1. A new borderline stage was created, on the basis of sample #2. The relationship between the PSD/LV and CPSD/CLV values was studied on sample #3 to verify the possibility of using the uncorrected indices instead of the CPSD/CLV. The relationship with other classification methods was studied on sample #4.


RESULTS
The GSS 2 showed a strong level of association with the AGIS and the Hodapp-Parrish-Anderson methods in staging defect severity. A good correlation was also found with a classification based on the Bebie curve.


CONCLUSIONS
The GSS 2 was able to correctly classify both damage severity and perimetric defect type in the sample studied, using either the corrected or uncorrected visual field indices. It is a quick and easy method, and its formulas can be introduced in any software.
Brusini
Paolo
P
Department of Ophthalmology--S. Maria della Misericordia Hospital, Udine, Italy. brusini@libero.it
Filacorda
Stefano
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005902:Glaucoma, Open-Angle / Q000145:classification* / Q000175:diagnosis; D006801:Humans; D008433:Mathematics; D008875:Middle Aged; D049451:Nomograms; D009798:Ocular Hypertension / Q000145:classification* / Q000175:diagnosis; D014786:Vision Disorders / Q000145:classification*; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields