discovering dry eye
Dry Eye Update From the 1999 AAO Meeting
BY KELLY KINNEY NICHOLS, OD, MS
As you may have noticed, dry eye has been a hot topic over the past year. New tests, drugs, contact lenses and other products have been introduced to help diagnose and manage patients who suffer from this ever-elusive condition. Last year's American Academy of Optometry (AAO) meeting in Seattle was no exception. This article highlights the cutting-edge information presented and my perspective on some of these dry eye tools.
Dry Eye Diagnosis Tools
Dr. Donald Korb and Akorn Ophthalmics formally introduced the Dry Eye Test (D.E.T.), a new method of evaluating fluorescein tear break-up time. The D.E.T. strips (Fig. 1) are smaller than traditional fluorescein strips, and deliver a 1µl volume of fluorescein to the tear film. In theory, this small volume induces much less reflex tearing and delivers a consistent amount of fluorescein, thus increasing accuracy and repeatability.
FIG. 1: Akorn Ophthalmics' D.E.T.
Punctal Occlusion Products
Also at the Academy meeting, Eagle Vision introduced the FlexPlug (Fig. 2), which is the only tapered shaft punctum plug that is equipped with contouring traction rings. The plug comes in the traditional sizes: 0.4, 0.5, 0.6, 0.7 and 0.9mm. The flexible rings bend and contract to better fit into the punctum and prevent "popping out."
FIG. 2: Eagle Vision's FlexPlug
Preliminary research results regarding Alcon Laboratories' thermoplastic "cast-in-place" punctal occlusion system were also presented. A multi-site study of the plug is ongoing, with 26 participants currently enrolled. In the dry eye patients being studied, a decrease in symptoms and an improvement in a few objective tests has been found. Statistical results were not presented. Removal of the plug requires irrigation with warm saline and is aided by the use of a petroleum-based gel.
Contact Lens Developments
Benz Materials launched the Extreme H2O soft contact lens. This lens is a group II disposable lens to be worn on a one-, two-, or four-week discard cycle. Preliminary studies have shown that the material resists drying, and may reduce end-of-day dryness symptoms.
The lens and the material, hioxifilcon A, will only be sold through practitioner offices. The company's Web site, www.extreme-h2o.com, is user-friendly and is set up so that patients can purchase contact lenses directly through the company online, and their practitioner receives the payment.
Other areas of research in dry eye presented at the AAO's annual meeting include the use of the Hartmann-Shack Wavefront Sensor in the evaluation of tear break-up with soft contact lens wear, reflex tearing associated with the phenol red thread test and the use of lissamine green staining in dry eye diagnosis. A significant amount of research is ongoing in this area, which can only translate to better patient care in the future.
Dr. Nichols is a graduate student at The Ohio State University College of Optometry in the area of dry eye research.