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Takuya Numata, Chota Matsumoto, Sachiko Okuyama, Sonoko Takada, Fumi Tanabe, Shigeki Hashimoto, Mariko Eura, Tomoyasu Kayazawa, Eiko Koike, Yoshikazu Shimomura; Detectability of Visual Field Defects using 0.5 Degree Interval in High Resolution Perimetry and OCT Findings. Invest. Ophthalmol. Vis. Sci. 2013;54(15):1886.
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© ARVO (1962-2015); The Authors (2016-present)
Visual field testing was performed using 0.5 degree interval in high resolution perimetry to assess detectability of visual field defects which were corresponded to OCT findings. Next, detectability of glaucoma-related visual field defects was investigated using measuring points of various intervals.
The subjects were 15 eyes of 15 patients with glaucoma and 15 eyes of 15 normal subjects. Octopus 900 Custom test program was used with the target size 3 and background luminance of 31.4asb. Measuring points were placed on the meridian of 45 degree superior-temporally between the fixation point and the eccentricity of 30 degrees and visual field at each measuring point was assessed three times with the interval of 0.5 degree and high degree visual field profile was obtained. The blind spot was detected using Octopus 900 Custom test with the target size 1, the background luminance of 31.4asb, target luminance of 1000asb, and a grid pattern of 1 degree interval. Visual field was overlapped exactly to fundus findings by matching the blind spot with the visual angle of the fixation point in visual field and the center of the disc and fovea in scanning laser ophthalmoscope (SLO). The corresponding structural findings were assessed using Cirrus HD-OCT with HD 5 Line Raster (1 line), 9 mm, High Definition Images. In normal eyes, visibility at retinal vessels was examined. In glaucoma cases, visual field profile was obtained using different degree intervals in 17 patterns from 0.5 degree to 8.5 degrees. Mean defect (MD), square root of loss variance (sLV) and maximum sensitivity decline amount in all degree intervals were examined.
In all the normal eyes, visual field testing with 0.5 degree interval presented decreased sensitivity caused by blood vessels by the average and maximum of 1.1dB, and 4dB. In the glaucoma cases, the detectability of visual field defects decreased when measuring points were located at intervals larger than 2 degrees, 3 degrees, and 6 degrees; at the eccentricity smaller than 10 degrees, 10 to 20 degrees, and 20 to 30 degrees, respectively, however, the advanced cases were least affected.
Detectability for glaucoma-related visual field abnormality is greatly affected by the measuring point density. The higher resolution perimetry is desirable at the central visual field.
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