Purpose: To evaluate the sensitivity and specificity of optic disk examinations performed using the Moorfields regression analysis (MRA) of the Heidelberg Retina Tomograph (HRT) in differentiating normal from glaucomatous eyes.
Design: Retrospective cross-sectional study.
Methods: Five hundred and nineteen patients were included in the study for a total of 193 normal eyes, 213 with suspected glaucoma (primary open-angle glaucoma [POAG]), and 113 with POAG. The intervention consisted of optic disk imaging by means of HRT I. A mean of three repeated images was analyzed using version 2.01 software. The optic disk was classified as "normal/outside normal limits" on the basis of the MRA. The visual field was examined using the DS 24 II program (Humphrey perimeter), with a glaucomatous visual field being defined on the basis of an abnormal Glaucoma Hemifield Test and a statistically significant corrected pattern standard deviation greater than 2 dB. The results obtained with MRA were compared with those obtained using the multivariate discriminant analysis (MDA) provided in the HRT I. The main outcome measures were sensitivity, specificity, and positive and negative predictive values of HRT examination.
Results: The sensitivity and specificity of the HRT-MRA examination were, respectively, 74% and 94% (83% and 75% with MDA) when the patients with suspected POAG were excluded from the analysis; the figures were 74% and 85%, and 41% and 94% (83% and 64%, and 60% and 75% with MDA) when the same patients were included as being normal or having POAG.
Conclusions: In a broad clinical setting including normal subjects, patients with suspected POAG, and POAG patients, the HRT-MRA showed a high degree of diagnostic accuracy. The MRA was less sensitive but more specific than MDA. Greater diagnostic ability may be added by HRT-MRA examinations than by HRT-MDA to standard POAG diagnostic studies.