Down Syndrome, Refractive Errors
Conditions
Brief summary
Individuals with Down syndrome (DS) live with visual deficits due, in part, to elevated levels of higher-order optical aberrations (HOA). HOAs are distortions/abnormalities in the structure of the refractive components of the eye (i.e. the cornea and the lens) that, if present, can result in poor quality focus on the retina, thus negatively impacting vision. HOAs in the general population are overall low, and thus not ordinarily considered during the eye examination and determination of refractive correction. However, for some populations, such as individuals with DS, HOAs are elevated, and thus the commonly used clinical techniques to determine refractive corrections may fall short. The most common clinical technique for refractive correction determination is subjective refraction whereby a clinician asks the patient to compare different lens options and select the lens that provides the best visual outcome. Given the cognitive demands of the standard subjective refraction technique, clinicians rely on objective clinical techniques to prescribe optical corrections for individuals with DS. This is problematic, because it may result in errors for eyes with elevated HOA given that these techniques do not include measurement of the HOAs. The proposed research evaluates the use of objective wavefront measurements that quantify the HOAs of the eye as a basis for refractive correction determination for patients with DS. The specific aim is to determine whether dilation of the eyes is needed prior to objective wavefront measurements. Dilation of the eyes increases the ability to measure the optical quality of the eye and paralyzes accommodation (the natural focusing mechanism of the eye), which could be beneficial in determining refractions. However, the use of dilation lengthens the process for determining prescriptions and may be less desirable for patients.
Interventions
The dilated refraction will be a trial spectacle frame composed of lenses based upon a spectacle prescription determined from dilated measures of the eye using a wavefront aberrometer.
The non-dilated refraction will be a trial spectacle frame composed of lenses based upon a spectacle prescription determined from non-dilated measures of the eye using a wavefront aberrometer.
Sponsors
Study design
Eligibility
Inclusion criteria
* Diagnosis of Down syndrome * Able to be dilated * Able to fixate for study measures * Able to respond for visual acuity testing
Exclusion criteria
* Ocular nystagmus * History of ocular or refractive surgery (strabismus surgery is okay) * Corneal or lenticular opacities * Ocular disease
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Distance Visual Acuity | 1 day | Distance (in LogMAR) visual acuity will be measured in the right eye with the British Standard Letter set or HOTV Matching for participants unable to name letters. Measurements will be obtained while the participant wears spectacle lenses based on their pre- and post-dilation refractions, respectively (from Visit 1). The order of testing is randomized. The primary outcome is the difference in distance visual acuity measurements calculated as visual acuity when wearing pre-dilation lens minus wearing post-dilation lens. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Near Visual Acuity | 1 day | Near visual acuity (in logMAR) will be measured with a Bailey-Lovie style HOTV card. Measurements will be obtained while the participant wears spectacle lenses based on their pre- and post-dilation refractions, respectively (from Visit 1). The order of testing is randomized. The outcome of interest is the difference in near visual acuity measurements calculated as visual acuity when wearing pre-dilation lens minus wearing post-dilation lens. |
| Participant Rating of Distance Vision Quality | 1 day | Participants will be asked to rate their quality of vision at near on a five-point scale where 1 will correspond to poorest vision and 5 will correspond to best vision. Ratings will be obtained at the end of testing with each spectacle lens (based on pre- and post-dilation refraction). |
| Participant Rating of Vision Quality at Near | 1 day | Participants will be asked to rate their quality of vision at near on a five-point scale where 1 will correspond to poorest vision and 5 will correspond to best vision. Ratings will be obtained at the end of testing with each spectacle lens (based on pre- and post-dilation). |
| Participant Overall Preference for Prescriptions | 1 day | Participants will be asked to select which of the two prescriptions (spectacles based on pre- or post-dilation) are preferred overall. |
Countries
United States
Contacts
Ohio State University
Participant flow
Recruitment details
Children (n=21) and adults (n=21) were enrolled in the study.
Pre-assignment details
Visit 1: All participants had pre- and post-dilation measures taken to determine refractions. Visit 2: Participants randomized to a single session testing schedule of either 1) pre-dilation then post-dilation refractions; or 2) post-dilation then pre-dilation refractions. Randomization was completed within strata based on age cohort. All participants from Visit 1 returned for testing.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 11.2 years STANDARD_DEVIATION 3.7 |
| Distance visual acuity (OD) | 0.41 logmar STANDARD_DEVIATION 0.21 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 4 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 8 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Near visual acuity | 0.26 logMAR STANDARD_DEVIATION 0.18 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants |
| Race (NIH/OMB) More than one race | 3 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 33 Participants |
| Sex: Female, Male Female | 4 Participants |
| Sex: Female, Male Male | 8 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 21 | 0 / 21 |
| other Total, other adverse events | 0 / 21 | 0 / 21 |
| serious Total, serious adverse events | 0 / 21 | 0 / 21 |