Retinafibrer

Retinafibrer, in English known as retinal nerve fibers, are the axons of retinal ganglion cells. They form the retinal nerve fiber layer (RNFL), which lines the inner surface of the retina and carries visual information toward the optic disc to form the optic nerve.

Anatomy and organization: The RNFL surrounds the inner retina and is thickest in the peripapillary region around the optic nerve head. The fibers originate from ganglion cells located in the ganglion cell layer and converge as they travel toward the optic nerve. In the macula, a prominent subset called the papillomacular bundle transmits central vision. Within the retina these axons remain unmyelinated; myelination begins only after the fibers pass through the lamina cribrosa at the optic nerve head.

Development and blood supply: Retinal nerve fibers are formed during retinal development as ganglion cells extend axons toward the brain. Their blood supply largely derives from the central retinal artery, with capillary networks supporting the nerve fiber layer in the peripapillary region.

Function: The RNFL transmits visual signals from photoreceptors, through intermediate neurons, to the brain via the optic nerve. This pathway ultimately relays information to the lateral geniculate nucleus and other visual centers for processing.

Clinical relevance: The RNFL is a key biomarker in ophthalmology. Optical coherence tomography (OCT) measures RNFL thickness to detect thinning associated with glaucoma and other optic neuropathies. Swelling of the RNFL can occur in acute optic neuritis or papilledema, while age-related thinning can occur naturally. Changes in RNFL thickness help guide diagnosis and monitoring of retinal and optic nerve diseases.