Purpose. Glaucoma suspect status due to asymmetric cupping represents a large proportion of glaucoma follow-up visits in most practices. Our purpose was to determine if asymmetric cupping was due to symmetric discs with decreased nerve fiber layer thickness or to asymmetric disc size without loss of neural tissue in our patient population. Methods. We retrospectively reviewed patients presenting to the glaucoma service with asymmetric cupping without elevated intraocular pressures or visual field loss by Humphrey visual field testing. Nerve fiber layer thickness was examined using optical coherence tomography (OCT). Cup and disc area were measured from stereoscopic photographs using a one millimeter square reticule three times by two investigators. Circular OCT scans of the optic nerve head were performed on patients to assess nerve fiber layer thicknesses. Results. A statistically significant difference in mean disc area of the larger disc versus the smaller disc was found [23.1 ± 4.3 square millimeters and 19.7 ± 4.8 square millimeters, N=33, p<0.0001]. Cup size was strongly related to disc size [r2=0.51, p<0.0001]. Nerve fiber layer thickness did not correlate with either cup or disk size. Additionally, we found that nerve fiber layer thickness did not correlate with changes in disc area in this patient population [r2= 0.01, N=33, p<0.0001]. Conclusions. Glaucoma suspects with clinically asymmetric cup-to-disc measurements were found to have asymmetric disc size in our patient population. Mean nerve fiber layer thickness correlated well between pairs of eyes independent of cup or disc size.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience