Myelinated Retinal Nerve Fibers Research Articles

Venöse Gefäßanomalien innerhalb myelinisierter retinaler Nervenfaserareale

We report the case of a 25 year old caucasian female who was presented to our clinic with a four year history of recurrent vitreous hemorrhages, myelinated retinal nerve fibers and ipsilateral anisometropic myopia, astigmatism and amblyopia of her right eye. On fluorescein angiography small, postcapillary venous malformations in the area of myelinization were diagnosed. Vascular anomalies within regions of myelinated retinal nerve fibers have not been described so far. Even if actual leakage itself from the anomalous vessels could not be documented, vitreous hemorrhaging did not recur after successful lasercoagulation and obliteration of the vascular anomalies.

Myelinated Retinal Nerve Fibers: Prevalence, Location and Effect on Visual Acuity

We examined fundus photographs of 5,789 patients (11,578 eyes) and found 39 patches of myelinated nerve fibers in 35 eyes of 33 patients. The prevalence was 0.57%. The lesion was more frequent in females than in males. The patch occurred more often at the superior sectors of the nerve head and in the inferotemporal retina than in other areas. No myelinated nerve fibers were discovered in the macula. One patient (case 1) had 3 patches in 1 eye. Two patients (cases 2 and 3) had unilateral myelinated nerve fibers, bilateral myopia and ipsilateral amblyopia. In case 3, the patch was associated with an epiretinal membrane. Another patient (case 4) had branch vein occlusion and neovascularization from the patch of myelinated nerve fibers. The fundus conditions observed in our cases 1-4 may be uncommon.

Atrophy of myelinated retinal nerve fibres following pituitary surgery: Report of a case

A 55-year-old man with bilateral myelinated retinal nerve fibres lost all vision in one eye and some vision in the other eye at the extirpation of a large pituitary adenoma. Eventually all myelin disappeared in the blind eye and some in the other eye. The process was not finished until more than 12 and nine months after surgery, respectively, and in the blind eye a smaller myelin patch disappeared earlier than a larger patch. Demyelination was secondary to postoperative descending optic atrophy.

Medullated retinal nerve fibers

Abstract. Myelinated retinal nerve fibers may cause fluctuating functional defects. In cases of association with neuro-ophthalmological disease, functional loss due to the medullated nerve fibers and due to the concomitant disease, may be difficult to evaluate.

Atrophy of Myelinated Retinal Nerve Fibers After Acute Optic Neuropathy

A 45-year-old man with extensive myelinated retinal nerve fibers had an attack of anterior ischemic optic neuropathy. Serial fundus photographs documented the loss of myelin. Visual acuity in the affected eye decreased to 6/90 (20/300) and color perception was markedly reduced. The visual fields in the affected eye showed dense superior and inferior arcuate scotomas and central depression. These findings were unchanged nine months later, but the areas of myelinated nerve fibers had become smaller.

Myelinated Retinal Nerve Fibers

In a series of 3,968 consecutive autopsies, myelinated nerve fibers of the retina were presented in 39 (0.98%) cases and bilateral in three (7.7%) affected cases; thus, 42 (0.54%) of the 7,936 eyes examined were affected. Myelinated nerve fiber lesions appeared as white or gray-white striated patches corresponding in shape to the distribution of retinal nerve fibers and demonstrated frayed borders. Myelinated retinal nerve fibers were continuous with the optic nerve head in 14 (33%) and discontinuous with the optic nerve head in 28 (66%) affected eyes. By light microscopy and electron microscopy, myelinated retinal fibers were marked by a ganglion cell axon surrounded by concentric lipoprotein lamellae that formed the myelin sheath. Glial cells were often prominent near the myelin sheaths, but other components of the sensory retina were morphologically normal. Clinically, 32 patients with myelinated retinal nerve fibers had comparable overall features, visual field defects less extensive than expected on the basis of ophthalmoscopic appearance, and normal findings on fluorescein angiography. Four patients had a syndrome characterized by ipsilateral extensive myelinated retinal nerve fibers, anisometropic myopia, amblyopia, and strabismus.

Myelinated Retinal Nerve Fibers Associated with Ipsilateral Myopia, Amblyopia, and Strabismus

Four patients had extensive unilateral myelinated nerve fibers associated with ipsilateral myopia, amblyopia, and strabismus. Their profound visual impairment, exotropia, and the early age onset of symptoms indicated that the amblyopia may have been organically caused. Prognosis is poor for even partial correction but good results have been obtained with intense therapy that includes full correction of the refractive error in each eye and extraocular muscle surgery if cosmetically necessary. In patients with axial myopia, images of a similar size will be produced by placing a lens of the correct power at the spectacle plane. In younger patients, a contact lens should not be used to correct the refractive error because it creates an undesirable anisometropia. Younger patients who have parafoveal fixation and no strabismus respond best to amblyopia therapy.