Individuals with Down syndrome suffer from significant ocular complications including high levels of lower-order refractive error (sphere and cylinder) and elevated levels of higher-order aberrations. These optical factors likely contribute to the poor acuity observed in this population. Current clinical prescribing practices may under-serve this community, as the cognitive demands of the subjective refraction sequence are difficult for this population and often leave clinicians to prescribe from objective clinical findings that target full correction of sphero-cylindrical refractive error. This prescribing practice can lead to sub-par outcomes given the fact that full lower-order corrections can exacerbate the effects of higher-order aberrations in more aberrated eyes.
For this study, individuals with Down syndrome will be dispensed three pairs of spectacles for 2 months each, in random order: one clinically-derived, and two objectively-derived refractions based upon methods designed to optimize a given metric of retinal image quality which takes into consideration the wavefront aberration measurements of the eye. Both initial and adapted visual acuity in the presence of each correction will be evaluated to determine whether the objectively-derived refractions outperform clinically-derived refractions.
