Abstract
Purpose: :
Although it is well-known that many infants treated for cataracts develop strabismus and/or nystagmus, little is known about the critical period for fixation stability and eye alignment. Here we evaluate how the onset and duration of visual deprivation affects ocular motor development.
Methods: :
Twenty-nine children who were treated for dense congenital or developmental cataracts were examined. Patients with sight-threatening complications were excluded. Eye alignment was assessed using prism and cover testing on a regular basis throughout follow-up by their surgeon. Fixation stability was determined from data obtained using eye movement recordings at ≥5 years of age. On the same visit, visual acuity and Randot stereoacuity were assessed. Eye movement records were analyzed by a masked examiner who was experienced in assessing disorders of fixation stability.
Results: :
Seventeen (59%) developed strabismus (15 ET, 1XT, 1 HT). Eight (28%) had infantile nystagmus, 11 (38%) had fusion maldevelopment nystagmus and the remaining 10 (34%) had normal fixation stability. Significant relative risk (RR) for strabismus was associated with whether the cataract was visually significant at ≤12months vs. >12months (RR=7.2; 95%CI: 1.1-46.3) but not with the duration of visual deprivation, unilateral vs. bilateral cataracts, or congenital vs. developmental cataracts. Significant relative risk (RR) for abnormal fixation stability was associated with duration of visual deprivation >4 weeks (RR=4.5; 95%CI: 1.3-15.6), nil stereoacuity (RR=6.9; 95%CI: 1.1-43.3) and visual acuity poorer than 20/40 (RR=4.1; 95%CI: 1.2-13.9) but not with whether cataracts were unilateral vs. bilateral, congenital vs. developmental, or presented at ≤12months vs. >12months.
Conclusions: :
Prompt surgery for congenital and developmental cataracts may be of benefit for ocular motor outcomes, including ocular alignment and fixation stability.
Keywords: visual development: infancy and childhood • amblyopia • eye movements