The Effects of a Senofilcon A Contact Lens With and Without a Photochromic Additive on Positive Dysphotopsia Across Age

Objective:

The visual effects of wearing a photochromic contact lens (test) were directly compared with a nonphotochromic contact lens (control). Positive dysphotopsia (halos, starbursts) and intraocular scatter (behaviorally determined) were assessed. Both younger and middle-aged subjects were evaluated to examine the influence of age.

Methods:

Fifty-four subjects (18–62 years) were tested using a contralateral design. Subjects were fit with a photochromic contact lens on one eye and a nonphotochromic contact lens on the other eye, randomly assigned. Testing occurred with and without photochromic activation (darkened) by use of a violet activator (365 nm, half-bandwidth 20 nm). The extent of dysphotopsia (halos and spokes) was measured using an aperture (∼4 mm) that created a bright point source of light 45 inches from the plane of the eye. Between the point source and subject, a centering precision caliper was used to measure lateral spread. Two-point thresholds were determined by measuring the minimum distance between two points of broadband xenon light.

Results:

The photochromic contact lens produced smaller halo diameters than the control contact lens, both activated (41% on average) and inactivated (21% on average), and age strata was a significant factor (P

Source: Eye and Contact Lens: Science and Clinical Practice - April 23, 2021 Category: Opthalmology Tags: Article Source Type: research