Glaucoma diagnosis optic disc analysis comparing Cirrus spectral domain optical coherence tomography and Heidelberg retina tomograph II

To evaluate the diagnostic ability of optic nerve head parameters, measured by Cirrus spectral domain optical coherence tomography (SD OCT) and Heidelberg retina tomograph II (HRT II) to detect concomitant glaucoma. Cirrus OCT and HRT examinations of 62 eyes of 62 patients (32 with no perimetric glaucoma and 30 with concomitant perimetric glaucoma) evaluated between August 2010 and December 2010 were retrospectively analyzed and compared with regard to the optic disc morphometric parameter, disc area, rim area, cup-to-disc ratio (CDR), and cup volume. Receiver operating characteristic curves were constructed for the parameters and areas under the curves (AUCs) were compared. All parameters except disc area were significantly different between Cirrus OCT and HRT. Average cup-to-disc ratio (CDR), vertical CDR, and cup volume were greater when measured by OCT compared with HRT II (P = 0.002, P < 0.001, and P < 0.001, respectively). Rim area was smaller by OCT than by HRT II (P < 0.001). Of the parameters evaluated, rim area (0.938), average CDR (0.865), and vertical CDR (0.897) had higher AUCs with OCT than with HRT II. Glaucoma diagnostic capability using the AUC was greater for OCT than for the HRT. Optic nerve head parameters measured by Cirrus OCT seem to be useful in differentiating glaucomatous optic nerve heads. The two types of instrument compared here should not be used interchangeably to obtain measurements of the optic disc for diagnosis of glaucoma.