Amblyopia treatment outcomes in patients with neurodevelopmental disorders

Abstract

Purpose: To compare amblyopia treatment outcomes between patients with neurodevelopmental disorders and their typically developing peers.

Methods: Of 2,311 patients diagnosed with amblyopia between 2010 and 2014 at Boston Children's Hospital, 460 met inclusion criteria (age 2-12 with anisometropic, strabismic, or mixed amblyopia [interocular difference (IOD) ≥2 lines]). Treatment and visual outcomes were analyzed according to neurodevelopmental status: neurodevelopmental delay (DD) versus typical development (TD).

Results: The DD group (n = 54) and TD group (n = 406) were similar in demographics, amblyogenic risk factors, baseline visual measures, prescribed therapy, and adherence (P ≥ 0.10). Between-visit follow-up time was longer for the DD group (0.65 [0.42- 0.97] years) than for the TD group (0.5 [0.36-0.82] years; P = 0.023). IOD improved similarly in each group by the last visit (DD, -0.15 logMAR [-0.31 to -0.02]; TD, -0.2 logMAR [-0.38 to -0.1]; P = 0.09). Each group reached amblyopia resolution by the last visit at similar frequencies (DD, 23/54 [43%]; TD, 211/406 [52%]; P > 0.2). DD diagnosis did not independently influence amblyopia resolution (HR, 0.77; 95% CI, 0.53-1.12; P = 0.17), but each additional month of interval time between follow-up visits reduced the likelihood of resolution by 2.7% (HR, 0.67; 95% CI, 0.51-0.87; P = 0.003).

Conclusions: Patients with DD and those with TD responded similarly to amblyopia therapy; however, follow-up intervals were longer in patients with DD and correlated with the likelihood of persistent amblyopia, suggesting that greater efforts at assuring follow-up may benefit patients with DD.

FIG 1.

Comparison of change in amblyopic eye best-corrected visual acuity (A) and change in interocular difference in typically developing patients versus patients with neurodevelopmental disorder at the 6-month visit and last visit (B). Box plots describe the median, 25th and 75th percentiles, with tails representing all other data and outliers are displayed as individual data points. Improvement in amblyopic eye visual acuity did not differ between groups at either visit.

FIG 2.

Kaplan-Meier curve of time to amblyopia resolution (IOD <2 logMAR lines) stratified by patient group. Solid lines represent the probability function of patients achieving amblyopia resolution over time, vertical ticks on the line represent the time point where a patient completed treatment without achieving resolution, and the shaded regions represent the 95% confidence intervals. Dashed black lines represent the median (50%) survival probability time points for each patient group. Log-ranked test comparing the two-survival function was not significant (P = 0.07).

FIG 3.

Forest plot of hazard ratios for amblyopia resolution in TD and DD patients. Boxes represent the calculated hazard ratios determined from Cox regression, and the left and right arms represent the 95% confidence interval of the hazard ratios.