Fig 1.
Identification of the defect location.
A) The superior disc edge identified on a fundus image obtained with the SS-OCT in reference to the color fundus photograph. In this case, the superior disc edge was located at the 90th scan of the sequential horizontal scans. B) The inferior disc edge was identified in a way similar to the superior edge. In this case, the inferior disc edge was located at the 180th scan. This means the center of the disc is located at the 135th scan. C) The location of the defect. A defect of the lamina cribrosa was identified in the OCT image (arrow). In this case the defect was located from 115th through 118th scan, which means the defect location is in the superior half of the disc. D) In the reference fundus image, a horizontal white line shows the location of the scan.
Fig 2.
Measurement of disc parameters.
Before the measurement, refraction, corneal curvature, and axial length were entered to the software to adjust for the ocular magnification effect. A) Ovality Index: Longest (1) and shortest (2) diameters of the optic disc were identified and manually traced. The length of the line was automatically calculated with the data management software (Imagenet R4). The ovality index was calculated by dividing the shortest disc diameter by the longest diameter. B) Disc Area: The edge of the optic disc was manually traced. The area surrounded by the line (= disc area) was automatically calculated. C) β-zone parapapillary atrophy area: First the line was manually drawn to enclose both optic disc and parapapillary atrophy. The area of the optic disc plus β-zone parapapillary atrophy was automatically calculated. Then the area of β-zone parapapillary atrophy was calculated by subtracting the disc area.
Table 1.
Baseline Demographics of the four groups.
Fig 3.
Representative cases with LC defects in A) the M group (high myopia without glaucoma), B) the G group (glaucoma without high myopia), and C) the MG group (glaucoma with high myopia), respectively.
Each panel shows (from left to right) infrared fundus images, OCT images, and SAP visual field printouts. The locations of the scan lines are shown as horizontal lines in infrared images (left panels). The arrows in OCT images show the locations of the defects (center panels).
Table 2.
Prevalence of LC defects in the four study groups.
Table 3.
Demographic and Ocular Factors in Eyes with and without LC Defects.