Peer-reviewed Articles

Please use the archived list on the right to look at past peer-reviewed articles.

1988

Fonn,D., Holden,B. A. Rigid gas-permeable vs. hydrogel contact lenses for extended wear. American Journal of Optometry and Physiological Optics 1988;65,7:536-544. [ Show Abstract ]

A clinical trail was conducted to compare the extended wear performance of rigid gas-permeable (RGP) contact lenses with that of soft lenses. Subjects were fitted with a RGP lens (Boston IV) in one eye and a soft lens (Bausch & Lomb 'O' series) in the other eye, and wore them on an extended wear basis for up to 3 months. No subjects developed any acute adverse reactions in the RGP lens-wearing eye. After the initial adaptation period, subject acceptance of RGP extended wear in terms of vision and comfort was superior. The RGP lenses also induced less chronic hypoxic stress than hydrogel lenses of comparable Dk/L, as evidenced by the presence of epithelial microcysts. Several complications of RGP extended wear were observed including lens binding, blepharoptosis, transient pupil size increases, and corneal staining. As hypoxia-induced corneal changes, such as microcysts and striae, were observed in the RGP lens-wearing eyes, we consider that these particular RGP lenses do not have adequate oxygen transmissibility for successful long-term extended wear. However, if RGP lens materials of higher oxygen transmissibility and better designs can be attained, the potential of RGP extended wear would appear promising.

Sorbara,L., Talsky,C. Contact lens wear in the dry eye patient predicting succes and achieving it
. Canadian Journal of Optometry 1988;50,4:234-241. [ Show Abstract ]

Clinical diagnosis of dry eye and its implications in successful contact lens wear has not been well defined. Two thousand patient files from the University of Waterloo, School of Optometry, Contact Lens Clinic were surveyed and 54 patients, diagnosed as having dry eye, were fit with contact lenses and were included in a retrospective prevalence study. Diagnostic procedures commonly used in the detection of dry eye were evaluated in terms of their ability to accurately predict successful lens wear in the dry eye patient. The Tear Break Up Time was found to be the most valid in identifying those patients who are less likely to achieve success. Schirmer`s Test was found to be of little predictive value. Possible correlations between lens type and successful lens wear were investigated. Dry eye patients fit with low water content, thin (0.06-0.10 mm) hydrogel lenses of differing water content or rigid gas permeable lenses. Additional factors which may serve to increase successful lens wear are briefly discussed.