Abstract
Abstract: :
Purpose: To evaluate visual function using frequency doubling technology perimetry (FDT) in patients with large cup-disc ratios with or without visual field defects based on standard automated perimetry (SAP). Methods: Sixty-nine glaucoma patients and suspects with vertical C/D of at least 0.8 based on masked stereo photograph assessment by at least 2 graders, and 52 normal subjects (IOP <= 22 mmHg, normal appearing optic discs and normal SAP) were included. One eye was randomly selected for the study. FDT and SAP were completed within a 3-month period. Stereo optic disc photographs were obtained within 12 months of FDT testing. Both types of visual fields were classified as abnormal if pattern standard deviation was < 5%. Results: Of the 69 patients, 67 had evidence of glaucomatous optic disc damage (rim thinning, excavation, nerve fiber layer defect, or cup/disc asymmetry in study eye ≷ 0.2mm relative to fellow eye). SAP mean deviation ranged from 0.82 to -19.02 dB (Mean ± SD, -4.42 ± 0.51 dB), and FDT ranged from 2.10 to -14.10 dB (-4.29 ± 0.43 dB). 35/69 (51%) of the patients had both abnormal FDT and SAP. 7/69 (10%) of patients had abnormal FDT and normal SAP. 10/69 (15%) of patients had normal FDT and abnormal SAP. At least one type of tests was abnormal in 75% of the patients. FDT was abnormal in only 2/52 (4%) of the normal subjects showing a high specificity for the criteria used to determine abnormality. There was no significant difference between the two tests in detecting visual functional loss in large C/D patients. The agreement was 75% (kappa =0.47). Conclusions: Patients with large C/D and normal standard visual field test can be a challenge for the diagnosis of glaucoma. FDT detected visual functional loss in some of these patients. However, SAP also selectively identified some eyes missed by FDT. When SAP and FDT were used together, the chance of detecting visual functional loss was increased. CR: None. Support: EY08208 (PAS) and EY 11008 (LZ)
Keywords: 624 visual fields • 498 optic disc • 511 perimetry