Abstract
Purpose: :
The GPA (Guided Progression Analysis) is a new software for study of progression with automated perimetry. It deliver 2 indexes : First, the VFI (visual field index) which rate of progression analysis is a trend analysis of patient’s overall visual field history. Second, the GPA Alert, message that indicates a significant deterioration noted in consecutive tests by an event analysis. We compare results of analysis with these new indexes and rate of progression analysis of classic Mean Deviation (MD) in Ocular Hypertension (OHT) and Early Primary Open Angle Glaucoma (POAG)
Methods: :
Prospective study on 305 eyes of 163 patients : 213 OHT and 92 Early POAG at beginning of the study. Patient’s mean age 69 (+/- 11.38). Each patient perform a mean number of 10 (+/- 3.6) automated perimetry tests (Sita Standard 24-II), with a mean follow up of 6,6 (+/- 1.7) years. For each group, we analyzed VFI, MD, their rate of progression, and compared results with the GPA Alert. For concordance and correlation study of all results, Cohen’s Kappa Coefficient (CKC) and Spearman’s rank correlation coefficient (SRC) were used.
Results: :
OHT Group: Rate of progression of VFI, of MD, and Alert GPA report a significant progression for respectively 18%, 24% and 16% of eyes. 25% of OHT eyes became POAG during follow upEarly POAG: VFI, MD and Alert GPA : significant progression for 28%, 39% and 33% of eyes. 18,5% became moderate or advanced POAG.Information about progression given by VFI and MD correspond for 83% in OHT group (CKC 0.504 P<0.001) and 80% of early POAG (CKC 0.558 P<0.001). Informations from VFI and GPA Alert correspond in : OHT: 86% (CKC 0.488 P<0.001), Early POAG: 76% (CKC 0.519 P<0.001). From MD and Alert GPA: OHT: 75% (CKC 0.244 P<0.01), Early POAG: 71% (CKC 0.383 P<0.001).Good correlation between rate of progression of VFI and MD has been reported: OHT: SRC 0.619 P<0.0001, Early POAG: SRC 0.707 P<0.0001.
Conclusions: :
Rate of progression of VFI and MD are 2 trend analysis. This could explain their good correlation. They are 2 complementary methods of progression visual field analysis.Correlation of these 2 indexes with GPA Alert (event analysis) is correct, but not so good.The 2 ways for progression analysis (trend and event) offered in new GPA software are very interesting. They do complementary evaluation of visual field in OHT and POAG. Nevertheless, correlation is better between VFI and MD.
Keywords: perimetry • visual fields