Investigating visual search performance in children with albinism and their peers with other visual impairment

Despite having comparable levels of visual functions, functional performance in a visual task may vary. Children with albinism had better visual search performance when compared with their other peers with visual impairments (VIs). Upon further investigation, the presence of nystagmus seemed to have a role in this performance outcome.

Individuals with albinism and VI (AVI) are shown to have near-normal reading speed akin to normally sighted (NS), whereas individuals with other causes of VI are known to have difficulty. We investigated if a similar observation can be obtained in other functional vision domains, such as visual search. Towards this aim, visual search performance was compared among three groups of children (NS, AVI, and VI).

Real-world images were presented on a computer screen along with a search target. Participants were asked to find and point to the search target within these images. A total of 150 trials were given to each child. Reaction time (time taken to find the target), accuracy, and integrated search performance score (a composite score accounting for time-accuracy trade-off) were analyzed. Comparisons between AVI and VI used univariate ANOVA after controlling for other factors (age, visual acuity, and contrast sensitivity).

Ninety-seven children (age: 5 to 17 years) participated (n = 26 NS, 31 AVI, and 40 VI). As expected, NS children had better performance (p≤0.005). While the accuracy of AVI was comparable to those with VI (p=0.068), AVI were significantly faster (p=0.002) and had a better integrated visual search performance score (p<0.001). Further subanalysis showed the AVI group had better performance (p<0.001) when compared with those with VI but without nystagmus (n = 23) and not when compared with the VI group with nystagmus (p=0.059). No difference in performance was observed between the two VI groups (p=0.081).

Despite having comparable visual functions, the AVI group performed better in a functional vision task than their peers with VI. Nystagmus seems to play a role in this visual performance. Further studies are needed to investigate this.