Abstract
Purpose: :
To compare the sensitivity and specificity for a new selective perimetry test, Heidelberg Edge Perimetry (HEP) with Frequency-Doubling Technology (FDT) perimetry in detecting early glaucomatous loss.
Methods: :
Healthy and open angle glaucoma subjects underwent full threshold 24-2 Humphrey Standard Automated Perimetry (SAP), full threshold 24-2 FDT Matrix perimetry, and a full threshold 24-2 Heidelberg Edge perimetry (HEP). FDT and HEP sensitivities and specificities were calculated for both groups and correlations were determined between FDT and HEP. The glaucoma group consisted of eighteen eyes with early open angle glaucoma (MD -1.07dB). Twelve of the eyes had glaucomatous optic disc neuropathy and/or a retinal nerve fiber layer defect and full fields using standard automated perimetry (SAP). The remaining six eyes had glaucomatous optic disc neuropathy and an early visual field defect on SAP. The mean age of the glaucoma group was 62.87+11.4 years. Twenty-one eyes made up the control group (normal intraocular pressure, normal optic nerve heads with full SAP) with a mean age 28.48+4.80 years old. All individuals had a visual acuity ≥ 20/40 and were free of any pathology or retinopathy that would result in visual field defects. No patient was taking a medication that would affect their visual field.
Results: :
Most of the patients with preperimetric glaucoma demonstrated functional losses on FDT and HEP, with more points flagged at P<1% and P<0.5% on HEP. HEP had an higher sensitivity when compared to FDT, but a lower specificity. (FDT, 44.44% sensitivity, 100% specificity; HEP 83.33% sensitivity, 76.19% specificity).
Conclusions: :
FDT and HEP detect functional losses in cases of glaucoma with normal SAP. HEP appears to be more sensitive than FDT matrix in detecting early functional loss. HEP may be useful in bridging the gap between structure and function in early glaucoma.
Keywords: perimetry • clinical (human) or epidemiologic studies: systems/equipment/techniques • visual fields