Hammond Billy R, Buch John, Sonoda Leilani, Renzi-Hammond Lisa
Department of Psychology (B.R.H.), Vision Sciences Laboratory, Behavioral and Brain Sciences Program, The University of Georgia, Athens, GA; Johnson and Johnson Vision Care, Inc (L.S.), Jacksonville, FL; and Department of Health Promotion and Behavior (L.R.-H.), Human Biofactors Laboratory, Institute of Gerontology, College of Public Health, The University of Georgia, Athens, GA.
Eye Contact Lens. 2021 May 1;47(5):265-270. doi: 10.1097/ICL.0000000000000731.
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.
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.
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<0.001) with the older group showing a greater reduction. The photochromic contact lens produced smaller starburst diameters than the control contact lens, both activated (37% on average) and inactivated (23% on average), and age strata was a significant factor (P=0.001) with the older group showing a greater reduction. The two-point thresholds were reduced (25% activated, 9% inactivated) on average but the age effect was not significant (P<0.10).
The senofilcon A lens with photochromic additive reduced the extent of positive dysphotopsia compared with the same lens without the additive, regardless whether the lens was activated or not. The visual benefit was greatest with the older subjects.
将佩戴光致变色隐形眼镜（测试组）的视觉效果与非光致变色隐形眼镜（对照组）直接进行比较。评估阳性畏光症（光晕、星芒）和眼内散射（行为测定）。对年轻和中年受试者均进行评估，以研究年龄的影响。
采用对侧设计对54名受试者（18 - 62岁）进行测试。受试者一只眼睛佩戴光致变色隐形眼镜，另一只眼睛佩戴非光致变色隐形眼镜，随机分配。使用紫色激活器（365 nm，半高宽20 nm）在有和无光致变色激活（镜片变深色）的情况下进行测试。使用一个孔径约4毫米的光圈测量畏光症（光晕和辐条）的程度，该光圈在距眼睛平面45英寸处产生一个亮点光源。在点光源和受试者之间，使用定心精度卡尺测量横向扩散。通过测量宽带氙灯光两点之间的最小距离来确定两点阈值。
光致变色隐形眼镜产生的光晕直径比对照隐形眼镜小，无论是激活状态（平均减小41%）还是未激活状态（平均减小21%），年龄分层是一个显著因素（P<0.001），老年组减小幅度更大。光致变色隐形眼镜产生的星芒直径比对照隐形眼镜小，无论是激活状态（平均减小37%）还是未激活状态（平均减小23%），年龄分层是一个显著因素（P = 0.001），老年组减小幅度更大。两点阈值平均降低（激活时降低25%，未激活时降低9%），但年龄效应不显著（P<0.10）。
与不含光致变色添加剂的同类型镜片相比，含光致变色添加剂的senofilcon A镜片可降低阳性畏光症的程度，无论镜片是否激活。老年受试者的视觉获益最大。
