Diagnostic Ability of Retinal Nerve Fiber Layer Thickness Deviation Map for Localized and Diffuse Retinal Nerve Fiber Layer Defects

Figure 1

(a) Localized wedge-shaped RNFL defect (yellow arrowheads) was observed at the inferotemporal region in red-free photography. (b) RNFL defect (blue line) was defined as at least 10 contiguous red (<1% level) superpixels in the RNFL deviation map. The center (black dot) of the RNFL defect was calculated with polar coordinates [ mm, θ = 314°] (: distance from the center of the optic disc, θ: angle from a temporal equator in a clockwise direction in right eyes and in a counterclockwise direction in left eyes). The angular width of the RNFL defect was determined as 7.52° where the boundary (blue line) of the RNFL defect met the circle (green arc) passing through the center of the RNFL defect. This was classified as a localized RNFL defect because of the angular width <30°. (c) In circumpapillary RNFL measurements, quadrant and clock-hour maps could not detect abnormalities at the corresponding area, although the TSNIT graph yielded suspicious downslope (black allows). (d) Diffuse RNFL defect (yellow arrowheads) was observed at the superotemporal region in red-free photography. The lower border was quite unclear for determination of the boundary. (e) The lesion was located at [2.11 mm, 39°] and corresponded to diffuse RNFL defect with angular width of 63.58°. (f) For a diffuse RNFL defect, circumpapillary RNFL measurements detected abnormalities at the corresponding area relatively well.

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