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.