Myelinated Retinal Nerve Fiber Layer (RNFL): A Comprehensive Review

Prevalence of common and rare ophthalmic findings in adults attending a medical survey institute

PURPOSE

To examine the ophthalmic data from a large database of people attending a general medical survey institute, and to investigate ophthalmic findings of the eye and its adnexa, including differences in age and sex.

METHODS

Retrospective analysis including medical data of all consecutive individuals whose ophthalmic data and the prevalences of ocular pathologies were extracted from a very large database of subjects examined at a single general medical survey institute.

RESULTS

Data were derived from 184,589 visits of 3676 patients (mean age 52 years, 68% males). The prevalence of the following eye pathologies were extracted. Eyelids: blepharitis (n = 4885, 13.3%), dermatochalasis (n = 4666, 12.7%), ptosis (n = 677, 1.8%), ectropion (n = 73, 0.2%), and xanthelasma (n = 160, 0.4%). Anterior segment: pinguecula (n = 3368, 9.2%), pterygium (n = 852, 2.3%), and cataract or pseudophakia (n = 9381, 27.1%). Cataract type (percentage of all phakic patients): nuclear sclerosis (n = 8908, 24.2%), posterior subcapsular (n = 846, 2.3%), and capsular anterior (n = 781, 2.1%). Pseudophakia was recorded for 697 patients (4.6%), and posterior subcapsular opacification for 229 (0.6%) patients. Optic nerve head (ONH): peripapillary atrophy (n = 4947, 13.5%), tilted disc (n = 3344, 9.1%), temporal slope (n = 410, 1.1%), ONH notch (n = 61, 0.2%), myelinated nerve fiber layer (n = 94, 0.3%), ONH drusen (n = 37, 0.1%), optic pit (n = 3, 0.0%), and ON coloboma (n = 4, 0.0%). Most pathologies were more common in males except for ONH, and most pathologies demonstrated a higher prevalence with increasing age.

CONCLUSIONS

Normal ophthalmic data and the prevalences of ocular pathologies were extracted from a very large database of subjects seen at a single medical survey institute.

Non-Invasive High-Resolution Imaging of In Vivo Human Myelinated Axons

This work aims to reveal the microscopic (2-3 micrometer resolution) appearance of human myelinated nerve fibers in vivo for the first time. We analyzed the myelinated retinal nerve fibers of a male patient without other neurological disorders in a non-invasive way using the transscleral optical phase imaging method with adaptive optics. We also analyzed the fellow eye with non-myelinated nerve fibers and compared the results with traditional ocular imaging methods such as optical coherence tomography. We documented the microscopic appearance of human myelin and myelinated axons in vivo. This method allowed us to obtain better details than through traditional ocular imaging methods. We hope these findings will be useful to the scientific community to evaluate neuro-retinal structures through new imaging techniques and more accurately document nerve anatomy and the pathophysiology of this disease.

Progressive Myelinated Retinal Nerve Fibers in Children With Craniosynostosis

The authors found the changes of myelinated retinal nerve fibers in one pair of identical twins with nonsyndromic craniosynostosis and two patients with Crouzon syndrome, who were at risk for impaired lamina cribrosa barrier function. This is the first report of progressive and presumed acquired myelinated retinal nerve fibers in craniosynostosis. [J Pediatr Ophthalmol Strabismus. 2021;58(6):e40-e43.].

Nevoid basal cell carcinoma syndrome: a case report and literature review

BACKGROUND

Nevoid basal cell carcinoma syndrome (NBCCS) is a rare genetic disorder associated with basal cell carcinomas (BCC), skeletal anomalies, and jaw cysts, and a number of ocular abnormalities. We describe a case of a 12-year-old boy diagnosed with NBCCS found to have several ophthalmic manifestations including a myelinated retinal nerve fiber. We conducted a literature review targeting the ocular and systemic manifestations of NBCCS, with a focus on the ophthalmic findings that have not been well characterized.

MATERIALS AND METHODS

We conducted a literature search from 1960 to 2021 utilizing specific keywords and criteria and excluded non-clinical articles. A total of 46 articles were ultimately used for the literature review.

RESULTS

In NBCCS, BCCs typically present before the age of 30 and gradually become numerous. Certain ocular features, less common in the general population, are much more common with NBCCS. Depending on the study, prevalence of these features in patients with NBCCS ranges from 26-80% for hypertelorism and 7-36% for myelinated retinal nerve fiber layer. Prevalence of nystagmus in patients with NBCCS was found to be approximately 6%. Systemic findings such as bilamellar calcification of the falx cerebri, palmar pits, and odontogenic keratocysts (OKCs) are also prevalent.

CONCLUSION

NBCCS may affect numerous organ systems, and thus requires a multidisciplinary team to manage. BCCs and jaw cysts are commonly occurring clinical features that have various surgical excisional options. The ocular anomalies of NBCCS are individually rare, and certain anomalies may present in the amblyogenic period of development and contribute to visual impairment.

Prevalence and Clinical Characteristics of Myelinated Retinal Nerve Fibres in a Chinese Teleophthalmology System

Purpose: To investigate the prevalence and clinical characteristics of myelinated retinal nerve fibre (MRNF) in a large teleophthalmology system.Methods: All records between January 2015 and December 2015 from Daheng Prust teleophthalmology system were reviewed by 2 ophthalmologists independently. MRNF was classified into continuous group and discontinuous group according to the relationship between MRNF patches and optic disc. The number, total area and location of MRNF patches were analysed. Concomitant ocular diseases were documented.Results: Out of 51469 subjects, MRNF was detected in 304 eyes of 263 subjects with a prevalence rate of 0.51 ± 7.1% per subject and 0.30 ± 5.4% per eye. Among 304 eyes with MRNF, 239 (78.6%) eyes were in continuous group and 65 (21.4%) eyes were in discontinuous group. Single MRNF patch was found in 249 (81.9%) eyes and multiple MRNF patches were found in 55 (18.1%) eyes. MRNF of small size was found in 150 (49.3%) eyes. The ratios of multiple MRNF patches and small-sized MRNF in the continuous group were significantly higher than those in the discontinuous group (P = .014 and P < .001). In continuous group, the MRNF patches were located most frequently in the superior region (68.6%) of the optic disc; In discontinuous group, the MRNF patches were located most frequently in the inferotemporal region (38.5%) of the retina. Epiretinal membrane (12 eyes, 3.9%) was the most common concomitant ocular disease.Conclusion: MRNF is uncommon in China. MRNF usually presents unilaterally and as a single small whitish patch that is connected with optic disc.

[Tumor-like diseases and retinal hamartomas in ophthalmological practice]

The article provides a detailed review of the ophthalmoscopic picture, optical coherence tomography (OCT) of the retina and fundus autofluorescence in patients with such rare pathological processes in the fundus as torpedo maculopathy, retinal myelin fibers, retinal astrocytic hamartoma and cavernous hematoma.

Bilateral Peripapillary Retinal Nerve Fiber Layer Myelination in a 26-Year-Old Man

Myelination is an uncommon condition that rarely causes visual impairment. We report a case of a young man with bilateral peripapillary nerve fiber layer myelination and visual impairment. The patient's complaints, clinical history, and systemic review were noted. Visual acuity test, objective and subjective refraction, ocular motility, fundus examination, optical coherence tomography, and low vision test, were performed. We compared our findings with published articles. We suggest that optic neuropathy was the cause of visual impairment in the patient.

Multimodal Imaging Characteristics of a Rare Co-occurrence of Optic Nerve Head Drusen and Peripapillary Myelinated Retinal Nerve Fibres

Although isolated optic nerve head drusen (ONHD) and peripapillary myelinated retinal nerve fibres (MRNF) are described in the literature many times as far as we could reach, the combination of the two has been reported in only a single case without multimodal imaging. Here, we present multimodal imaging of a 47-year-old healthy woman with MRNF who had blind spot enlargement and a visual field defect in the left eye ascribed to the ONHD. ONHD may accompany MRNF which can hide the disc drusen. Clinicians, therefore, should be aware of this rare coexistence to explain possible complications such as visual field defects associated with drusen in patients with MRNF.