DISEASE
Straatsma syndrome is a rare disease entity characterized by the traditional triad of unilateral myelinated retinal nerve fibers (MNRF), axial myopia, and amblyopia.
The original description of the condition also included strabismus. Variations of the triad include a “reverse Straatsma syndrome ”, in which patients exhibit hyperopia instead of myopia.
Even though nystagmus and strabismus have not been prominently associated with Stratsma syndrome, either may be present as complimentary findings without precluding one from the diagnosis.
Even though Straatsma syndrome has traditionally been considered a unilateral disorder, cases of bilateral Straatsma syndrome and bilateral reverse Straatsma syndrome have also been reported.
Diagnosis
MRNF appears as a white lesion usually contiguous with the optic nerve head. The distribution is along the retinal nerve fiber layer and typically feather-like appearance is noted at the margin.
The MRNF does not cross the horizontal raphe. MRNF may be separate from the optic disc and may be present in the peripheral retina.
Despite some controversy in its diagnostic features, it should be included in the differential diagnosis of leukocoria and must be suspected in the presence of refractive errors with anisometropia.
Fundus Explorer Pro
Photograph the retinal findings described here with the phone already in your pocket — 22 D optics and built-in illumination in one handheld unit.
From Choroida — the team behind this siteMANAGEMENT
The management includes providing proper refractive correction and ruling our systemic associations.
Prognosis
The visual prognosis of amblyopia associated with myelination of retinal nerve fibers and anisometropia is poorer than anisometropic amblyopia without myelination.
It is well known that the former is refractory to occlusive therapy. Despite having a poor prognosis, visual rehabilitation should be attempted.
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Two smartphone imaging tools built for everyday clinic use — one for the slit lamp, one for the fundus.
From Choroida — the team behind this siteREFERENCES
- Juhn, A. T., Houston, S. K., & Mehta, S. (2015). BILATERAL STRAATSMA SYNDROME WITH NYSTAGMUS. Retinal Cases & Brief Reports, 9(3), 198–200. doi:10.1097/icb.0000000000000137
- Straatsma BR, Heckenlively JR, Foos RY, Shahinian JK. Myelinated retinal nerve fibers associated with ipsilateral myopia, amblyopia, and strabismus. Am J Ophthalmol. 1979 Sep;88(3 Pt 1):506-10. doi: 10.1016/0002-9394(79)90655-x. PMID: 484678.
- Shenoy R, Bialasiewicz AA, Al Barwani B. Bilateral hypermetropia, myelinated retinal nerve fibers, and amblyopia. Middle East Afr J Ophthalmol 2011;18:65–66
- Levy NS, Ernest JT. Retinal medullated nerve fibers. Arch Ophthalmol 1974;91:330–331
- Congenital optic disk anomalies [Internet]. W.B. Saunders; 2013 [cited 2021 May 19]. Available from: https://www.sciencedirect.com/science/article/pii/B9780702046919000510
- Rosen B, Barry C, Constable IJ. Progression of myelinated retinal nerve fibers. Am J Ophthalmol. 1999 Apr;127(4):471-3. doi: 10.1016/s0002-9394(98)00377-8. PMID: 10218709.
- Quezada-Del Cid NC, Zimmermann-Paiz MA, Ordoñez-Rivas AM, Burgos-Elías VY, Marroquin-Sarti MJ. Straatsma syndrome: Satisfactory amblyopia treatment. Report of two cases. Arch Soc Esp Oftalmol. 2018 Jun;93(6):300-302. English, Spanish. doi: 10.1016/j.oftal.2017.12.010. Epub 2018 Feb 15. PMID: 29398227.
