Acute acquired concomitant esotropia (AACE) is an unusual presentation characterized by acute onset of esotropia after infancy. For patients with AACE of adulthood, the outcome of surgery, which is a common treatment, often shows successful recovery of stereopsis. However, whether surgically corrected patients with AACE of adulthood achieved balanced eyes is yet unclear. Here, we used a binocular phase combination paradigm to quantitatively assess the ocular dominance of 22 surgically aligned patients with AACE of adulthood, which all had regained normal stereopsis after the surgery and 14 adult controls with normal vision. The sensory eye dominance was quantified as the interocular contrast ratio, termed balance point, at which each eye contributed equally to the perception of cyclopean grating. We found that, normal controls had a mean balance point value close to unity (0.96 ± 0.01), whereas adult AACE patients exhibited apparent interocular imbalance (0.76 ± 0.04), which was significantly different from control group (Mann-Whitney U = 135, P < 0.001, two tailed). In addition, the balance point of adults with AACE didn't correlate with the interval between onset of esotropia and the surgery (r = - 0.262, p = 0.239), or the length of postoperative follow-up period (r = 0.127, p = 0.575). Our results suggest that, for patients with AACE of adulthood whose eyes had been straightened, there is still residual sensory imbalance which may be a potential risk factor for AACE of adulthood.
Read full abstract