Ocular Dominance Determined by Near Point of Convergence Test in Intermittent Exotropia

ABSTRACT

This study was designed to validate the usefulness of the near point of convergence(NPC)test in determination of dominant & non-domnant eyes in intermittent exotropia patients. We performed NPC test in 36 intermittent exotrpic patients, and then, determined the non-dominant eye which deviated outward beyond the NPC. The dominant eyes determined by the NPC were compared to those that were determined by amblyopia, sensory fusion and photophobia. Best corrected visual acuity was used to divide patients into two groups 26 patients without amblyopia, and 10 with amblyopia. Among the amblyopia group, if the eyes with better visual acuity were taken as dominant eyes, then eight(80%)cases were identical with the NPC test and two(20%)cases were different. Ten patients had sensory anomaly, and among then, nine(90%)cases were identical with the NPC test and one(10%)case was different. Twenty six(64%)patients had photophobia in one eye and all(100%)cases were identical with the NPC test. In intermittent exotropia, determination of dominant eye by the NPC test showed high coincidence with other tests. Therefore, we suggest that the NPC test is an easy and accurate method in determining either the dominant or non-dominant eye for surgery.