Spectacles for Patients With Down Syndrome

Not Applicable

Completed

Brief Summary: This study tests the hypothesis that objectively derived spectacle prescriptions based on wavefront aberration measurements of the eyes of individuals with Down syndrome can provide an improvement in visual acuity over that obtained with spectacle prescriptions based on standard clinical prescribing techniques. The objectively derived prescriptions are derived using strategies to optimize retinal image quality as measured by image quality metrics, and thus these prescriptions will be referred to as metric-derived.

Detailed Description: 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.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Nystagmus (Involuntary beating movement of the eyes)
Visually significant media opacities (e.g. cataracts or corneal scars)
Strabismic amblyopia (reduced vision in one eye related to a constant eye-turn)
Anisometropic amblyopia (reduced vision in one eye related to a long-standing uncompensated difference in prescription between the two eyes)

Primary Outcome Measures

Name	Time	Method
Adapted Visual Acuity	two months	Aided LogMAR distance visual acuity obtained with either the British Standard Letters or HOTV - matching for subjects unable to name letters.

Secondary Outcome Measures

Name	Time	Method
Spectacle Assessment Survey Question 2	two months	Participants were asked to select a face from a survey with five expressions (large frown, small frown, neutral, small smile, large smile) depicting their response to the question 'How well do you see with this pair of glasses when looking far away?' Responses were coded 1 through 5 with 5 = large smile.
Spectacle Assessment Survey Question 1	two months	Participants were asked to select a face from a survey with five expressions (large frown, small frown, neutral, small smile, large smile) depicting their response to the question 'Do you like wearing this pair of glasses?' Responses were coded 1 through 5 with 5 = large smile.
Initial Visual Acuity	1 day	Aided LogMAR distance visual acuity obtained with either the British Standard Letters or HOTV - matching for subjects unable to name letters.
Spectacle Wear Time	two months	Total wear time of each pair of spectacles as measured objectively by a temperature sensor data logger mounted to the spectacle temple.
Spectacle Assessment Survey Question 3	two months	Participants were asked to select a face from a survey with five expressions (large frown, small frown, neutral, small smile, large smile) depicting their response to the question 'How well do you see with this pair of glasses when looking up close?' Responses were coded 1 through 5 with 5 = large smile.