Trial Outcomes & Findings for Evaluation of Multifocal Contact Lens Designs With and Without an HEV Blocker on Visual Function (NCT NCT04995055)

A total of 37 subjects were enrolled into this study. Of those enrolled, 35 were fit into at least 1 study lens, while 2 subjects failed to meet all eligibility criteria. Of those dispensed, 25 subjects completed the study, while 10 subjects were discontinued.

Evaluation of Multifocal Contact Lens Designs With and Without an HEV Blocker on Visual Function

The starburst diameter (mm) was measured each subject binocularly. Starburst diameter was quantified by the horizontal spread of the spokes emerging from the center of a small, point-like stimulus. A calibrated custom-made micrometer (two sides with reverse threading) was used to spread two posts out from a central mid-point. The posts attach to a custom-designed ruler that indicates the lateral spread of the starburst. Measurements for this metric are positive. Smaller diameter indicates better lens performance. The average diameter (mm) for each lens type was reported by period.

Halo diameter (mm) was quantified and measured using the same micrometer as for starbursts diameter (mm). The Halo diameter (mm) was measured each subject binocularly. Measurements for halo diameter are positive, where smaller values indicate better performance. The average diameter (mm) for each lens type.

Glare disability threshold was collected binocularly for each subject. Subjects were exposed to a target stimulus for 2 seconds; before the measurement was taken the annulus was set to a level below that which would cause the target stimulus to be veiled. The experimenter would then adjust the intensity of the annulus until subjects could no longer see the target stimulus. Subjects would indicate this by pressing a buzzer. Glare disability thresholds take on positive values, where higher values indicate better lens performance. The average glare disability level (change in log relative energy) for each lens type was reported.

The Glare discomfort was evaluated by calculating the change in height of the palpebral fissure measured while the participant views the mid-wave central grating target, compared to the maximal squint during a 5-second Photostress exposure induced by a solid, 10-degree broadband field, which completely obscures the target (\~10-deg diameter). Both eyes were recorded and averaged, to produce an average palpebral fissure height before and during the Photostress exposure. Glare discomfort can take on negative and positive values, where smaller values indicate better lens performance. The average glare discomfort (change in palpebral fissure height) for each lens type was reported.

Using the same optical bench set-up described Glare Disability Threshold, to measure HCT, participants viewed the mid-wave (580 nm) grating target presented on presented on a short wave (460 nm) "sky-light background." The intensity of the background was adjusted, until the participant was no longer able to resolve the grating target. The log relative energy of the background needed to obscure the central target was recorded as HCT. Heterochromatic contrast thresholds are positive values, where higher values indicate better lens performance. The average threshold each lens type was reported.

To create the two-point threshold stimulus, a single point- source like stimulus was spread into two distinct points of light, using a custom-built, collapsible light baffle. The two-point threshold was quantified as the minimum distance (mm) at which a participant could detect two distinct points of light, separated by a small black space. Measurements for this metric are positive. Smaller distances indicate better lens performance. The average distance for each lens type and period.

To create the two-point threshold stimulus, a single point- source like stimulus was spread into two distinct points of light, using a custom-built, collapsible light baffle. The two-point threshold was quantified as the minimum distance (mm) at which a participant could detect two distinct points of light, separated by a small black space. Measurements for this metric are positive. Smaller distances indicate better lens performance. The average distance for each lens type.