Influence of Power Changes in Single Cut Rigid Contact Lenses on Tear Pump Efficiency
نویسندگان
چکیده
منابع مشابه
Tear film surface quality with rigid and soft contact lenses.
OBJECTIVES The aim of this study was to measure tear film surface quality (TFSQ) using dynamic high-speed videokeratoscopy during short-term (8 hrs) use of rigid and soft contact lenses. METHODS A group of 14 subjects wore 3 different types of contact lenses on 3 different nonconsecutive days (order randomized) in 1 eye only. The subjects were screened to exclude those with dry eye. The lense...
متن کاملTear flow under hydrogel contact lenses.
The tear replenishment rate under three different hydrogel lenses was determined with a slit lamp modified to serve as a fluorophotometer. Fractional tear volume replenishment rates under these lenses averaged 0.011 per blink, which is significantly lower than the 0.10 to 0.20 per blink reported for rigid lenses. These data suggest that the amount of oxygen delivered to the cornea by tear pumpi...
متن کاملTear exchange and contact lenses: a review.
Tear exchange beneath a contact lens facilitates ongoing fluid replenishment between the ocular surface and the lens. This exchange is considerably lower during the wear of soft lenses compared with rigid lenses. As a result, the accumulation of tear film debris and metabolic by-products between the cornea and a soft contact lens increases, potentially leading to complications. Lens design inno...
متن کاملInfluence of Tear Protein Deposition on the Oxygen Permeability of Soft Contact Lenses
Purpose. To investigate the effect of tear protein deposition on the change in oxygen permeability (Dk) of soft contact lenses (SCL). Methods. Three hydrogel lenses (polymacon, nelfilcon A, and etafilcon A) and two silicon hydrogel lenses (lotrafilcon A and balafilcon A) were investigated. Etafilcon A lenses were incubated in artificial tear solution for 1, 6, 12, and 48 h, whereas the other SC...
متن کاملUltrahigh-resolution measurement by optical coherence tomography of dynamic tear film changes on contact lenses.
Purpose. To determine the dynamic pre- and postlens tear film (PLTF and PoLTF) thicknesses by using optical coherence tomography (OCT). Methods. Ultrahigh-resolution OCT was used to image the tear film of 22 subjects before and after contact lens wear. A soft lens with 1 drop of artificial tears on its concave surface was inserted onto one randomly selected eye. OCT images were taken before ins...
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ژورنال
عنوان ژورنال: Optometry and Vision Science
سال: 1992
ISSN: 1040-5488
DOI: 10.1097/00006324-199209000-00004