Effect of Peripapillary Vitreous Opacity on Retinal Nerve Fiber Layer Thickness Measurement Using Optical Coherence Tomography

Figure 1. Retinal nerve fiber layer thickness measurements in case 1. A, At the first examination, a peripapillary vitreous opacity (arrows) was detected outside the scan circle (outermost circle in the deviation map). B, At the second examination, the vitreous opacity (arrows) had moved to the adjacent area, where the scan circle met the opacity, and the retinal nerve fiber layer thickness at the 5-o’clock sector (arrowhead) had decreased from 78 to 58 μm. C, At the third examination, the vitreous opacity (arrow) was positioned exactly on the nasal side of the optic nerve head, the optic disc center was displaced inferior-nasally in the deviation map, the disc margin was changed, and the retinal nerve fiber layer thickness increased in the superior-temporal area (10- to 12-o’clock sectors) and decreased in the inferior-nasal area (4- to 7-o’clock sectors) (arrowheads).

Figure 2. Retinal nerve fiber layer thickness measurements in case 2. A, At the first examination, a peripapillary vitreous opacity (arrows) was detected outside the scan circle (outermost circle in the deviation map). B, At the second examination, the vitreous opacity (arrows) had crossed the scan circle and the retinal nerve fiber layer thicknesses of the 6- and 7-o’clock sectors (arrowheads) had decreased from 119 to 102 μm and 132 to 47 μm, respectively. C, At the third examination, although the vitreous opacity (arrow) crossed the scan circle, the retinal nerve fiber layer thickness change was not remarkable.

Figure 3. Retinal nerve fiber layer thickness measurements in case 3. A, At the first examination, there was no vitreous opacity floating around the optic disc. B, At the second examination, a peripapillary vitreous opacity (arrow) crossing the scan circle was found but was not associated with a substantial retinal nerve fiber layer thickness change.