Diagnostic ability of the Heidelberg retina tomograph, optical coherence tomograph, and scanning laser polarimeter in open-angle glaucoma.

PURPOSE: To compare the ability to discriminate between healthy and glaucomatous eyes of different criteria based on parameters from 3 optical imaging devices: Heidelberg retina tomograph (HRT-II), optical coherence tomograph (Stratus OCT 3000) and scanning laser polarimeter (GDx VCC). DESIGN: Cross-sectional study. PARTICIPANTS: A total of 139 eyes from 139 subjects were enrolled in this study and classified into 66 healthy subjects and 73 glaucomatous patients according to intraocular pressure and standard automated perimetry. METHODS: All the subjects underwent complete ophthalmic examination, including HRT-II, OCT, and GDx VCC evaluations. MAIN OUTCOME MEASURES: Several parameters were obtained by these techniques and 8 diagnostic criteria were assessed. Receiver operating characteristics curves were plotted and compared among them, and sensitivity for specificity higher than 95% was calculated for every criterion. Agreement among the 3 technologies was assessed by means of Venn diagrams. RESULTS: The best criteria discriminating between healthy and glaucomatous eyes were Moorfields regression analysis out of the 95% confidence interval (HRT-II), OCT retinal nerve fiber layer average thickness <77 microm, and nerve fiber indicator >37 (GDx VCC) with sensitivities of 85%, 66%, and 48%, with specificity higher than 95%. Sixty-six patients out of 73 were correctly identified by at least 1 of the devices and 30 were detected by the 3 of them. CONCLUSIONS: Structural criteria assessed by the optical imaging devices evaluated in this study are useful to discriminate glaucomatous damage.

Sub-clinical atrophy of the retinal nerve fibre layer in multiple sclerosis.

PURPOSE: This study aimed to evaluate the presence of abnormalities in the retinal nerve fibre layer (RNFL) in multiple sclerosis (MS) patients with normal ophthalmic examination, and to compare the ability of optical coherence tomography (OCT) and scanning laser polarimetry (GDx) to detect axonal loss. METHODS: Patients with MS and disease-free controls were invited to enrol in the study from 1 February 2007 to 30 June 2008. Ophthalmic examination, including evaluation of visual acuity (VA) and visual field (VF), showed normal results in all subjects. Retinal nerve fibre layer properties were measured by means of OCT and GDx. Visual evoked potentials (VEPs) were also recorded. RESULTS: Forty eyes of 40 MS patients and 20 eyes of age- and sex-matched controls were included in the study. Despite normal VA and VF results, significant differences between the two groups were observed in VF mean deviation (MD), most of the RNFL measurements provided by OCT and GDx, and VEP P100 latency and amplitude. There was a significant correlation between OCT and GDx parameters, and between these parameters and VEP results. Nineteen MS eyes (35.7%) showed RNFL abnormalities detected either by OCT or GDx. DISCUSSION: Sub-clinical ganglion cell loss can be detected in MS patients with normal visual function. Both OCT and GDx are useful complementary tools with which to identify this damage.