Appropriate addition power for aphakic infants determined by a smart wearable device Clouclip.

Clinical relevance: It is particularly important to perform reasonable and effective optical correction to enable visual development after primary lens removal surgery for congenital cataracts. Aphakic infants need a suitable addition power of prescription (ADD) to help them focus on close visual objects.

Background: It is challenging to obtain appropriate ADD power for infants due to poor cooperation and lack of subjective feedback. We aimed to determine the appropriate ADD for aphakic infants using a recently developed smart wearable device called Clouclip.

Methods: The study was a cross-sectional, observational pilot study. Twenty-three aphakic infants (aged from 6 months to 3.5 years) were invited to wear a smart wearable device for 7 days consecutively to monitor the near viewing distance in real life. Viewing habits and its associations with the possible influencing factors were investigated based on the data obtained from the device.

Results: The average proportion of near viewing time was 77.9% (95% confidence interval (CI) 72.1-83.7%). The average of the median near viewing distance was 23.8 cm (95% CI 20.6 cm-27.0 cm), which corresponded to an ADD of +4.25 D (95% CI + 3.75 D - +4.75 D) spectacle prescription. The height of the child was found to be positively correlated with the median of near viewing distance (r = 0.646, p = 0.001). Age, current ADD, age of cataract extraction surgery and bilaterality or monocularity of the aphakic eyes showed no significant correlation with the aforementioned viewing habits (all p > 0.05).

Conclusion: By using the novel wearable device, we found the suitable ADD of spectacle prescription for aphakic infants is about +4.25 D. The height of the child was an influencing factor for ADD.