Straatsma Syndrome: A Fundoscopic Signature

Abstract

We present the case of a 6-year-old boy with developmental delay who presented to our clinic with left exotropia, severe amblyopia, and high myopia. He had been previously seen four years prior but missed several appointments since. The cover–uncover test revealed exotropia of the left eye (LE), with full extraocular motility bilaterally. Best corrected visual acuity (BCVA) was 0.8 in the RE and 0.16 in the LE, with resistance to further RE occlusion. Cycloplegic retinoscopy showed RE: +0.50 and LE: –10.25 +3.00×90. Anterior segments were unremarkable. The dilated LE fundus examination is shown here.

Straatsma syndrome (STAS) is defined by a triad of unilateral myelinated retinal nerve fibers (MRNF), amblyopia, and high myopia, and is often associated with strabismus, as in our case.[1–3] Other reported associations include heterochromia iridum, nystagmus, retinal telangiectasia, and vitreoretinal degenerations. [1,2] MRNF can interfere with visual development by blocking the transmission of retinal impulses to the lateral geniculate nucleus, resulting in visual deprivation and axial elongation. [1,2] Amblyopia may result from structural changes caused by MRNF, refractive error, or strabismus, all of which were present in our patient. [1,2]

Even though STAS is associated with poor visual prognosis, prescription of a cycloplegic refraction and intensive occlusion therapy should always be attempted. [1–4]