Abstract
Purpose: :
To compare the ability of optic disc and retinal nerve fiber layer (RNFL) imaging to discriminate perimetrically unaffected eyes of glaucoma patients from normal eyes.
Methods: :
: Forty–six primary open–angle glaucoma patients with glaucomatous visual field loss with achromatic perimetry in one eye and a normal visual field in the fellow eye, and 46 normal controls were selected. Receiver operator characteristic (ROC) curves, sensitivities at fixed specificities were used to compare the performance of StratusOCT (Fast RNFL algorithm), GDx–VCC, HRT II and clinical evaluation of stereoscopic optic disc photographs to distinguish perimetrically unaffected eyes of glaucoma patients from normal eyes.
Results: :
The average mean deviation of perimetrically unaffected eyes was –0.8 ± 1.5 dB. The parameters with the largest area under the ROC curves (AUC) were: inferior average RNFL thickness (0.92 ± 0.03) for StratusOCT; linear cup/disk ratio (0.82 ± 0.05) for HRT II; and nerve fiber layer index (0.69 ± 0.06) for GDx–VCC. Clinical evaluation of disc photographs provided AUCs ranging between 0.80 and 0.85. The p values for pairwise comparisons of the AUCs of OCT’s best parameter with those of HRT, GDx and disc photographs were: 0.06, < 0.001, and 0.17 respectively. The sensitivities at ≥ 95% specificity for the best parameters from StratusOCT (inferior average), HRT II (cup volume), GDx–VCC (TSNIT Average) and clinical evaluation of disc photographs were 61%, 39%, 37% and 28% respectively. OCT performed significantly better to discriminate perimetrically unaffected glaucomatous eyes from normal eyes than HRT (p = 0.001), GDx (p = 0.001) or clinical evaluation of disc photos (p < 0.001).
Conclusions: :
Optical coherence tomography (StratusOCT) was more sensitive than other imaging techniques and clinical evaluation of disc photographs for detecting glaucomatous damage in perimetrically unaffected eyes of primary open–angle glaucoma patients.
Keywords: optic disc • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical