Reproducibility of minimum rim width and retinal nerve fibre layer thickness using the Anatomic Positioning System in glaucoma patients.

OBJECTIVE: To determine the test-retest repeatability of minimum rim width and retinal nerve fibre layer thickness measurements obtained by spectral-domain optical coherence tomography using the Anatomic Positioning System protocol in glaucoma patients and controls. Also, to assess the ability of the minimum rim width and retinal nerve fibre layer thickness to diagnose glaucoma in 2 circular peripapillary locations. METHODS: Spectral domain optical coherence tomography scans of the optic nerve head were obtained twice during the same visit using the Anatomic Positioning System eye-tracking protocol. The minimum rim width and retinal nerve fibre layer thickness were measured at 3 circular diameters (3.5 mm, 4.1 mm, and 4.7 mm). Intraclass correlation coefficients and area under the receiver operating characteristic were calculated for these parameters. RESULTS: A total of 36 glaucomatous eyes and 59 control eyes were included in the analysis. The intraclass correlation coefficients of minimum rim width and retinal nerve fibre layer thickness global measurement for 3.5 mm and 4.1 mm circles ranged between 0.98 and 1.00 and for 4.7 mm circle was between 0.76 and 1.00. The minimum rim width had an area under the receiver operating characteristic of 0.97, while the retinal nerve fibre layer thickness measurements had an area under the receiver operating characteristic of 0.95, 0.95, and 0.96 for the 3.5 mm, 4.1 mm, and 4.7 mm circles, respectively. CONCLUSIONS: The minimum rim width and retinal nerve fibre layer thickness measurements using the Anatomic Positioning System protocol had overall excellent reproducibility and diagnostic performance. Using this protocol and the novel minimum rim width parameter may be useful in more accurate diagnosis and follow-up of patients with glaucoma.

Validation and reproducibility of the Heidelberg Edge Perimeter in the detection of glaucomatous visual field defects.

AIM: To validate the ability of the Heidelberg Edge Perimeter (HEP) in detecting glaucomatous visual field (VF) defects compared to the Octopus Visual Field (OVF) Analyzer and to determine the test-retest repeatability of both modalities. METHODS: This prospective, cross-sectional study was conducted at Wills Eye Hospital, Philadelphia, PA. Glaucoma subjects and unaffected controls underwent VF testing using HEP standard automated perimetry (SAP) III 30-2 Adaptive Staircase Thresholding Algorithm (ASTA) FAST protocol and OVF G-TOP white-on-white strategy. Testing order was randomized. Pearson's correlation coefficient was calculated for both mean deviation (MD) and pattern standard deviation/square root of loss of variance (PSD/sLV). Receiver operating characteristic (ROC) curves were used to determine the diagnostic abilities of both modalities. Glaucoma subjects returned for repeat testing and intraclass correlation coefficients (ICCs) were calculated to assess test-retest repeatability. RESULTS: Seventy-nine subjects with glaucoma and 36 unaffected controls were enrolled. HEP and OVF were significantly correlated for both MD (r=-0.84; P<0.01) and PSD/sLV (r=0.79; P<0.01). Areas under the ROC curves (AUCs) were also comparable between HEP and OVF for both MD (0.74 and 0.79, respectively; P=0.26) and PSD/sLV (0.74 and 0.82; P=0.08). ICC was high for both HEP (0.96 for MD, 0.95 for PSD/sLV) and OVF (0.82 and 0.88, respectively). Mean test duration (min) was significantly shorter for OVF (2.63) compared to HEP (5.15; P<0.01). CONCLUSION: HEP and OVF show strong correlation for both MD and PSD/sLV, and have similar validity for detecting glaucoma. The test-retest repeatability is high for both HEP and OVF, however the average testing duration of HEP is significantly longer than that of OVF.