The most common causes of AHP were determined as fourth cranial nerve palsy (33.7%), Duane retraction syndrome (21.5%), sixth cranial nerve palsy (11%), nystagmus blockage syndrome (9.8%) and Brown syndrome (6.7%).
Amblyopia was most common in nystagmus blockage syndrome (100%) and least common in Duane retraction syndrome (16.0%).
(8) Incomitant strabismus was also a prominent cause of ocular AHP in the present study, and the five most common causes were fourth nerve palsy (33.7%), Duane retraction syndrome (21.5%), sixth nerve palsy (11%), nystagmus blockage syndrome (9.8%), and Brown syndrome (6.7%).