FDT Matrix 24‐2 threshold strategy for the evaluation of glaucoma suspects and ocular hypertensive eyes

Abstract

Abstract Purpose: To evaluate FDT Matrix 24‐2 threshold strategy diagnostic performance in discriminating healthy subjects from glaucoma suspects (GS) and ocular hypertensives (OH) patients. Methods: 23 healthy subjects, 27 OH, 21 GS and 20 EG patients were recruited. Classification was based on optic disc and Humphrey Field Analyzer (HFA) perimetry criteria (glaucoma if PSD<95% and/or GHT outside normal limits). A complete ophthalmologic evaluation, HFA (24‐2, SITA standard) and FDT perimetry (24‐2, ZEST strategy) were performed in all subjects. A severity score (from 1 for points with <5% probability up to 4 for probability <0.5%) was calculated from defective points on pattern deviation map and mean values (±SD) in the 4 groups were compared at Mann‐Whitney test. AUROC curves were created in order to assess MD, PSD and severity score diagnostic accuracy. Results: MD and PSD displayed chance discriminating power in OHs (AUROC<0.6) on both instruments. For GSs, FDT‐MD and PSD have larger but not statistically significant AUROC than HFA. For EG, diagnostic performance of the two instruments is very similar with excellent AUROC (>0.9). Severity score on the 2 instruments are similar for OHs, whereas significance limit was nearly reached (p=0.057) for GSs and significant difference appeared (p=0.002) for EG eyes with higher score on FDT. Conclusions: FDT Matrix 24‐2 threshold strategy apparently does not offer advantages over HFA in OH and EG. In GS, statistically significant improvement in diagnostic accuracy was not demonstrated, probably because of insufficient sample size. Thus, the role of FDT Matrix in clinical practice needs further investigation.