Ocular findings in two siblings with Joubert syndrome
A 6-year-old boy presented with ptosis and strabismus of his left eye along with an abnormal head posture. He had delayed motor and language development with episodic hyperpnea–apnea spells and hypotonia in infancy. JS diagnosis was made on the basis of the characteristic MTS on MRI () and neurological findings observed in the pediatric clinic. He showed mild facial dysmorphism in the form of forehead prominence and bilateral epicanthic folds. He had ptosis, hypotropia, and exotropia in his left eye (). His abnormal head posture included a head tilt to the left and turning his face to the left. On ophthalmic examination, the best-corrected visual acuity in his right eye was 0.8 with +0.25 D −1.00 D ×90°, and 0.5 with +0.50 D −2.00 D ×60° in his left eye. The prism cover test demonstrated that there was 20 prism diopter hypotropia and 35 prism diopter exotropia of his left eye. The patient was unable to maintain his eyes in a central position by convergence, and he had horizontal pendular nystagmus. Slit-lamp examination showed no other abnormalities in either of his eyes. Funduscopy showed mild chorioretinal discoloration at the peripapillary region in both eyes (, arrows). Additionally, a small coloboma was detected at the inferior region of his right optic disc (, arrowhead). OCT (RS-3000; NIDEK, Gamagori, Japan) showed that the foveal architecture was preserved in both eyes, although there was poor recording due to nystagmus ().