Optic disk and nerve fiber layer imaging to detect glaucoma.

PURPOSE: To compare optic disk and retinal nerve fiber layer (RNFL) imaging methods to discriminate eyes with early glaucoma from normal eyes. DESIGN: Retrospective, cross-sectional study. METHODS: In a tertiary care academic glaucoma center, 92 eyes of 92 subjects (46 with early perimetric open-angle glaucoma and 46 controls) were studied. Diagnostic performance of optical coherence tomography (StratusOCT; Carl Zeiss Meditec, Dublin, California, USA), scanning laser polarimetry (GDx VCC; Laser Diagnostic Technologies, San Diego, California, USA), confocal laser ophthalmoscopy (Heidelberg Retinal Tomograph [HRT] III; Heidelberg Engineering GmbH, Heidelberg, Germany), and qualitative assessment of stereoscopic optic disk photographs were compared. Outcome measures were areas under receiver operator characteristic curves (AUCs) and sensitivities at fixed specificities. Classification and regression tree (CART) analysis was used to evaluate combinations of quantitative parameters. RESULTS: The average (+/- standard deviation) visual field mean deviation for glaucomatous eyes was -4.0 +/- 2.5 dB (decibels). Parameters with largest AUCs (+/- standard error) were: average RNFL thickness for StratusOCT (0.96 +/- 0.02), nerve fiber indicator for GDx VCC (0.92 +/- 0.03), Frederick S. Mikelberg (FSM) discriminant function for HRT III (0.91 +/- 0.03), and 0.97 +/- 0.02 for disk photograph evaluation. At 95% specificity, sensitivity of disk photograph evaluation (90%) was greater than GDx VCC (P = .05) and HRT III (P = .002) results, but not significantly different than those of StratusOCT (P > .05). The combination of StratusOCT average RNFL thickness and HRT III cup-to-disk area with CART produced a sensitivity of 91% and specificity of 96%. CONCLUSIONS: StratusOCT, GDx VCC, and HRT III performed as well as, but not better than, qualitative evaluation of optic disk stereophotographs for detection of early perimetric glaucoma. The combination of StratusOCT average RNFL thickness and HRT III cup-to-disk area ratio provided a high diagnostic precision.

Frequency doubling perimetry and short-wavelength automated perimetry to detect early glaucoma.

PURPOSE: To compare the ability of short-wavelength automated perimetry (SWAP) and frequency doubling perimetry (FDP) to detect early glaucoma damage. DESIGN: Prospective case-control study using a comparative case series. PARTICIPANTS: Forty-two patients with preperimetric glaucomatous optic nerve damage and a normal standard achromatic perimetry (SAP) in 1 eye, but with contralateral SAP abnormalities, and 35 normals. METHODS: Forty-two patients and 35 normals underwent SWAP and FDP (Humphrey 24-2; Carl Zeiss Meditec, Inc., Dublin, CA). Correlations of mean deviation (MD) and pattern standard deviation (PSD) of the 2 groups were calculated. The number of defects at P<0.05 and P<0.01 on total deviation (TD) and pattern deviation (PD) plots were compared. Diagnostic precision and agreement on location of abnormalities were determined. MAIN OUTCOME MEASURES: Correlations and comparisons of global indices between SWAP and FDP: MD, PSD, TD, and PD abnormal number of points. RESULTS: Significant correlations in the glaucoma group were found between SWAP and FDP for MD (r = 0.54; P<0.008) and PSD (r = 0.49; P<0.001). Defects on the TD and PD plots were detected more frequently by FDP in the glaucoma group, although they were significant only for PD at P<0.01 (P = 0.024). Areas under receiver operator characteristic curves for MD of SWAP and PSD of FDP were 0.74 and 0.67, respectively (P = 0.37). Using defined defect criteria, FDP had a significantly higher sensitivity (72% vs. 54%; P = 0.02) and similar specificity (53% vs. 44%; P = 0.12) compared with SWAP. Agreement on defect location was moderate (kappa, 0.46). Testing time for SWAP was longer than for FDP in both glaucomatous and normal eyes (P<0.001). CONCLUSIONS: Short-wavelength automated perimetry and FDP showed similar ability to detect visual dysfunction in patients with preperimetric glaucoma. Long-term follow-up is required to define their role in predicting subsequent SAP defects.

Frequency-doubling perimetry: comparison with standard automated perimetry to detect glaucoma.

PURPOSE: To compare second generation frequency-doubling perimetry (FDP) with standard automated perimetry (SAP) to detect glaucomatous visual field abnormalities. DESIGN: Prospective, cross-sectional, controlled observational study. METHODS: Fifty eyes of 50 patients with glaucoma with confirmed SAP visual field abnormalities and 42 eyes from 42 normal control subjects were studied. Swedish Interactive Thresholding Algorithm (SITA) standard 24-2 SAP and FDP visual fields were performed. The correlation of global indices and the number of defects on total deviation (TD) and pattern deviation (PD) plots were compared. The spatial concordance of FDP and SAP defect locations was determined. RESULTS: In patients with glaucoma, significant correlations of mean deviation (MD) and pattern standard deviation (PSD) were found between SAP and FDP (P < .001 for MD and P < .001 for PSD), but not in the normal group. FDP had significantly greater defect scores than SAP on total deviation and PD plots in the glaucoma group (P = .028 and P = .01, respectively). In comparison with SAP, sensitivity and specificity of FDP were 92% and 98% with glaucoma hemifield test criteria and 98% and 93% with PSD <5% criteria, respectively. Similarly high diagnostic precision was found with MD and PSD (at 95% specificity; MD and PSD sensitivity was 82% and 90%, respectively). The location of defects within 12 hemifield clusters found with FDP agreed moderately well with those detected with SAP (kappa = .48). CONCLUSIONS: FDP and SAP perform similarly in their ability to detect visual field defects in early to moderate glaucoma. Larger and deeper defects detected with FDP suggests the possibility of earlier detection at high specificity.