Sensitivity and specificity with the glaucoma probability score in Heidelberg Retina Tomograph II in Japanese eyes

To evaluate the sensitivity and specificity with glaucoma probability score (GPS), a new glaucoma diagnosis program in Heidelberg Retina Tomograph II ver 3.0 in detecting early glaucoma in Japanese eyes.

Sensitivity and specificity with GPS were determined in 148 early stage open-angle glaucoma eyes of 148 hospital-based patients (mean deviation >-5 dB) and age-matched and refraction-matched 148 eyes of 148 ophthalmologically normal subjects selected from a population-based sample of the Tajimi Study. The results with GPS were compared with those with Moorfields regression analysis (MRA) and FS Mikelberg discriminant function (FSM). Analysis was also carried out by stratifying the eyes by refraction and disc area.

For all glaucoma eyes, sensitivity with GPS (71.7%) was similar to MRA and FSM (75.2%, P=0.8; 77.2%, P=0.5; Fisher exact test). Specificity with GPS (80.7%) was also statistically equivalent with MRA and FSM (91.1%, P=0.06; 87.4%, P=0.3). Although sensitivity with GPS was lower in higher myopic eyes than in the less myopic eyes, specificity did not differ with refractive error. Specificity with GPS was lower and sensitivity higher (P<0.0001) in larger discs (>2.0 mm) than in smaller discs (< or =2 mm). In larger discs, specificity with GPS was lower (P=0.005) than with MRA and in smaller discs, sensitivity with GPS was lower than with MRA or FSM.

In Japanese eyes, sensitivity and specificity with GPS to detect early glaucoma were similar with MRA or FSM, although the specificity tended to be lower than results in white eyes. Subgroup analysis revealed a notable dependency in diagnostic ability on disc area and refractive error. The diagnostic ability of GPS is still not sufficient for glaucoma detection in the Japanese population requiring further investigation.