Repeatability and Reproducibility of Retinal Nerve Fiber Layer Parameters Measured by Scanning Laser Polarimetry with Enhanced Corneal Compensation in Normal and Glaucomatous Eyes.

OBJECTIVE: To assess the intrasession repeatability and intersession reproducibility of peripapillary retinal nerve fiber layer (RNFL) thickness parameters measured by scanning laser polarimetry (SLP) with enhanced corneal compensation (ECC) in healthy and glaucomatous eyes. METHODS: One randomly selected eye of 82 healthy individuals and 60 glaucoma subjects was evaluated. Three scans were acquired during the first visit to evaluate intravisit repeatability. A different operator obtained two additional scans within 2 months after the first session to determine intervisit reproducibility. The intraclass correlation coefficient (ICC), coefficient of variation (COV), and test-retest variability (TRT) were calculated for all SLP parameters in both groups. RESULTS: ICCs ranged from 0.920 to 0.982 for intravisit measurements and from 0.910 to 0.978 for intervisit measurements. The temporal-superior-nasal-inferior-temporal (TSNIT) average was the highest (0.967 and 0.946) in normal eyes, while nerve fiber indicator (NFI; 0.982) and inferior average (0.978) yielded the best ICC in glaucomatous eyes for intravisit and intervisit measurements, respectively. All COVs were under 10% in both groups, except NFI. TSNIT average had the lowest COV (2.43%) in either type of measurement. Intervisit TRT ranged from 6.48 to 12.84. CONCLUSIONS: The reproducibility of peripapillary RNFL measurements obtained with SLP-ECC was excellent, indicating that SLP-ECC is sufficiently accurate for monitoring glaucoma progression.

The relationship between structure and function as measured by OCT and Octopus perimetry.

BACKGROUND/AIMS: To determine the structure-function relationship between equivalent visual field areas obtained with the Octopus perimeter (OP), and the peripapillary retinal nerve fibre layer (RNFL) thickness measured with spectral-domain optical coherence tomography (OCT) in healthy individuals and patients with glaucomatous optic neuropathy. METHODS: Eighty-eight normal subjects and 150 patients with open-angle glaucoma were prospectively recruited. Eligible participants for the glaucoma group were required to have elevated intraocular pressure and glaucomatous optic nerve head morphology. All participants underwent reliable automated perimetry with OP, and optic nerve head imaging with the Cirrus OCT. Principal component analysis of the mean threshold values for the visual field test points were performed independently for each hemifield. Pearson correlations were calculated between visual field regions and RNFL thickness sectors. RESULTS: Mild to moderate correlations were observed between the visual field regions and the peripapillary RNFL thicknesses. Each visual field region was significantly correlated with more than one RNFL sector, and vice versa. The strongest correlation was observed between the RNFL thickness at 5 and 7 clock-hour positions and the superonasal region of OP (r=0.63). CONCLUSIONS: Retinal sensitivity evaluated with OP correlated moderately well with the RNFL thickness measured by OCT. There was an overlap of the visual field regions within the optic disc.

Assessment of the optic disc morphology using spectral-domain optical coherence tomography and scanning laser ophthalmoscopy.

OBJECTIVE: To compare the equivalent optic nerve head (OHN) parameters obtained with confocal scanning laser ophthalmoscopy (HRT3) and spectral-domain optical coherence tomography (OCT) in healthy and glaucoma patients. METHODS: One hundred and eighty-two consecutive healthy subjects and 156 patients with open-angle glaucoma were divided into 2 groups according to intraocular pressure and visual field outcomes. All participants underwent imaging of the ONH with the HRT3 and the Cirrus OCT. The ONH parameters and the receiver operating characteristic (ROC) curves were compared between both groups. RESULTS: Mean age did not differ between the normal and glaucoma groups (59.55 ± 9.7 years and 61.05 ± 9.4 years, resp.; P = 0.15). Rim area, average cup-to-disc (C/D) ratio, vertical C/D ratio, and cup volume were different between both instruments (P < 0.001). All equivalent ONH parameters, except disc area, were different between both groups (P < 0.001). The best areas under the ROC curve were observed for vertical C/D ratio (0.980 for OCT and 0.942 for HRT3; P = 0.11). Sensitivities at 95% fixed-specificities of OCT parameters were higher than those of HRT3. CONCLUSIONS: Equivalent ONH parameters of Cirrus OCT and HRT3 are different and cannot be used interchangeably. ONH parameters measured with OCT yielded a slightly better diagnostic performance.

Relationship between spectral-domain optical coherence tomography and standard automated perimetry in healthy and glaucoma patients.

OBJECTIVE: To evaluate the relationship between spectral-domain optical coherence tomography (OCT) and standard automated perimetry (SAP) in healthy and glaucoma individuals. METHODS: The sample comprised 338 individuals divided into 2 groups according to intraocular pressure and visual field outcomes. All participants underwent a reliable SAP and imaging of the optic nerve head with the Cirrus OCT. Pearson correlations were calculated between threshold sensitivity values of SAP (converted to linear scale) and OCT parameters. RESULTS: Mean age did not differ between the control and glaucoma groups (59.55 ± 9.7 years and 61.05 ± 9.4 years, resp.; P = 0.15). Significant differences were found for the threshold sensitivities at each of the 52 points evaluated with SAP (P < 0.001) and the peripapillary retinal nerve fiber layer (RNFL) thicknesses, except at 3 and 9 clock-hour positions between both groups. Mild to moderate correlations (ranging between 0.286 and 0.593; P < 0.001) were observed between SAP and most OCT parameters in the glaucoma group. The strongest correlations were found between the inferior RNFL thickness and the superior hemifield points. The healthy group showed lower and weaker correlations than the glaucoma group. CONCLUSIONS: Peripapillary RNFL thickness measured with Cirrus OCT showed mild to moderate correlations with SAP in glaucoma patients.