PURPOSE The purpose of this study was to measure upper and lower tear menisci on contact lenses using real time optical coherence tomography (OCT). METHODS Both eyes of 20 adapted contact lens wearers were imaged when they wore two types of silicone hydrogel lenses, balafilcon A on one eye and galyfilcon A on the other eye. The height, radius, and area of upper and lower tear menisci were obt...

PURPOSE To determine the effects on corneal epithelial permeability and ocular response of 30 nights of continuous wear (CW) of gas permeable (GP) and silicone hydrogel (SiH) contact lenses. METHODS Ninety-one subjects successfully completed 30 days of CW of either GP (n = 42) or SiH (n = 49) contact lenses. Epithelial permeability (P(dc)) was measured by scanning fluorometer at an afternoon ...

PURPOSE Previous studies of optical interference from the whole thickness of the precorneal tear film showed much lower contrast than from the pre-contact lens tear film. It is hypothesized that the recorded low contrast is related to roughness of the corneal surface compared with the smooth contact lens surface. This hypothesis is tested, and characteristics of this roughness are studied. ME...

PURPOSE To investigate the in vitro dehydration process of conventional hydrogel and silicone-hydrogel contact lens materials. METHODS Eight conventional hydrogel and five silicone-hydrogel contact lenses were dehydrated under controlled environmental conditions on an analytical balance. Data were taken at 1-min intervals and dehydration curves of cumulative dehydration (CD), valid dehydratio...

PURPOSE To compare central corneal swelling after eight hours of sleep in eyes wearing four different silicone hydrogel lenses with three different powers. METHODS Twenty-nine neophyte subjects wore lotrafilcon A (Dk, 140), balafilcon A (Dk, 91), galyfilcon A (Dk, 60) and senofilcon A (Dk, 103) lenses in powers -3.00, -10.00 and +6.00 D on separate nights, in random order, and on one eye only...

PURPOSE The purpose of the present study was to develop mathematical relationships that allow obtaining equilibrium water content and refractive index of conventional and silicone hydrogel soft contact lenses from refractive index measures obtained with automated refractometry or equilibrium water content measures derived from manual refractometry, respectively. METHODS Twelve HEMA-based hydr...