What is RNFL eye?
The retinal nerve fiber layer (RNFL) or nerve fiber layer, stratum opticum, is formed by the expansion of the fibers of the optic nerve; it is thickest near the optic disc, gradually diminishing toward the ora serrata.
Is RNFL the optic nerve?
The RNFL of the retina contains the nonmyelinated axons of the retinal ganglion cells that form the optic nerve. The retinal ganglion axons are packed together in bundles that are viewed as striations of the RNFL during fundus examination.
What is normal RNFL symmetry?
Most people should demonstrate symmetry between the right and left eye’s RNFL (as measured along the Circular Tomogram). Asymmetry is a common marker for early Glaucoma. The color coding (green, yellow, red) will help you distinguish if any asymmetry is statistically significant or not.
What is a normal average RNFL thickness?
Results. Average (±SD) RNFL thickness for normal subjects was found to be 102.37 ± 7.45 (range, 82–119 microns) compared with 90.74 ± 14.50 found for glaucoma subjects. Females had higher average RNFL values (104.84 ± 6.90) compared with males (99.80 ± 7.18).
Can you have glaucoma with normal RNFL?
Before a functional loss such as a visual field defect is displayed, a large number of nerve fibers can be damaged. However, there are glaucoma patients in which an apparently normal RNFL coexists with evident visual field defects.
What causes retinal thinning?
Extreme nearsightedness (myopia) Previous eye surgery, such as cataract removal. Previous severe eye injury. Previous other eye disease or disorder, including retinoschisis, uveitis or thinning of the peripheral retina (lattice degeneration)
What is the RNFL layer?
The retinal nerve fiber layer (RNFL) is composed primarily of ganglion cell axons before they coalesce in the optic nerve. Early postmortem studies by Hinton et al. (1986) demonstrated the axonal degeneration of the optic nerve and decreased thickness of the RNFL in AD patients.
What is normal macular thickness on OCT?
The OCT software determined the center (mean ± SD central foveal thickness) to be 207 ± 18 μm.
What is normal RNFL thickness on OCT?
Average RNFL thickness indicates a patient’s overall RNFL health. The mean value for RNFL thickness in the general population is 92.9 +/- 9.4 microns. Typically, a normal, nonglaucomatous eye has an RNFL thickness of 80 microns or greater.
What causes retinal nerve fiber layer thinning?
RNFL thinning is seen on OCT in both glaucoma and nonglaucomatous optic neuropathies and central nervous system diseases. These diseases include ischemic optic neuropathy, optic neuritis, hereditary optic neuropathy, traumatic optic neuropathy, MS, and degenerative diseases such as Alzheimer’s and Parkinson’s disease.