To evaluate the natural history of myelinated retinal nerve fiber layer (MRNFL) through clinical features and enhanced depth imaging optical coherence tomography.
This is a retrospective, noncomparative, case series of patients who underwent thorough clinical examination to document associated ocular and systemic features. Enhanced depth imaging optical coherence tomography was performed when MRNFL was located posteriorly and accessible to imaging.
Seventy-two eyes of 62 patients had a total of 86 MRNFL lesions. Enhanced depth imaging optical coherence tomography (n = 42 eyes) showed that all lesions originated in the nerve fiber layer with preservation of the vascular structures. Mean thickness by enhanced depth imaging optical coherence tomography was 255 μm (median, 182 μm; range, 61–717 μm). Natural history was obtainable in 58 lesions with a mean follow-up duration of 57 months (median, 37 months; range, 2–253 months) with no significant change overall in largest basal diameter (2.5 vs. 2.5 mm; P = 0.361) or thickness (255 vs. 240 μm; P = 0.053). However, evidence of lesion change included growth in base only (≥0.5 mm) (3 of 58; 5%), growth in base (≥0.5 mm) and thickness (≥50 μm) (3 of 58; 5%), and reduction in base (≥0.5 mm) after plaque radiotherapy for choroidal melanoma (3 of 58; 5%).
In general, MRNFL is a rare, benign retinal finding with a potential for growth in 10% of cases. This supports previous histopathological reports that MRNFL represents accumulation of both myelin and oligodendrocytes and could be an oligodendrocytic choristoma.
The study focuses on the natural history and imaging of myelinated retinal nerve fiber layer and documents growth and regression of these lesions, supporting the theory that myelinated retinal nerve fiber layer could represent an oligodendrocytic choristoma.
Ocular Oncology Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, Pennsylvania.
Reprint requests: Carol L. Shields, MD, Ocular Oncology Service, Wills Eye Hospital, Thomas Jefferson University, 840 Walnut Street, Suite 1440, Philadelphia, PA 19107; e-mail: firstname.lastname@example.org
Supported by the Eye Tumor Research Foundation, Philadelphia, PA (JAS, C.L.S.).
None of the authors has any conflicting interests to disclose.
The funders had no role in the design and conduct of the study, in the collection, analysis and interpretation of the data, and in the preparation, review, or approval of the manuscript. C. L. Shields has had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.