Ocular manifestations (strabismus: duane syndrome; and retinal nerve fiber hypoplasia) in okihiro syndrome (duane radial ray syndrome).

Background and purpose: Two siblings diagnosed with Okihiro Syndrome (also named Duane Radial Ray Syndrome) associated with ophthalmic manifestation including Duane Syndrome and retinal nerve fiber layer (RNFL) hypoplasia were presented.

Methods: The first patient (15-years old female) was diagnosed of Duane Syndrome presenting reduction of visual acuity and pale optic discs. She showed a diffuse decrease in the RNFL thickness, mainly in her left eye, retaining the typical RNFL morphology as double hump, demonstrated by OCT and scanning laser polarimetry. Neurophysiology evaluation found a decrease in visual evoked potentials and pattern electroretinogram amplitudes, and an increase of the latency of P100 component. The second patient (12 year-old female) presented with Duane malformation. Both patients underwent a complete ophthalmic evaluation with best corrected visual acuity, visual field examination, optical coherence tomography (OCT), scanning laser polarimetry, visual evoked potentials, pattern electroretinogram, and genetic study.

Results: The neuro-ophthalmic evaluation showed a subclinical reduction of RNFL average thickness provided by OCT and an increase of P50 and N95 latency by pattern electroretinogram. RNFL average thickness presented a score reduction in both patients, without typical glaucomatous morphology.

Conclusions: Our analyses suggest that Okihiro Syndrome may affect retinal nerve fiber layer development and visual acuity.