Contact Lenses are Medical Devices
Unfortunately, many people mistakenly believe that contact lenses are simply cosmetic items that anyone can pick up “over the counter” and place in the eye. In addition, most people do not realize that improper use of contact lenses combined with certain eye conditions can result in eye disease. And at worst; that a contact lens related eye infection can cause permanent loss of vision. Consequently, contact lenses are an FDA-regulated product for which a valid prescription is necessary.
A proper contact lens evaluation involves the following:
- Consultation and history: Choosing the appropriate lens for your lifestyle and environment.
- Evaluation for ocular disease and eye issues that may cause problems with contact lens use.
- Corneal Topography – Corneal curvature examination assisted b computer analysis. A corneal topographer projects a series of illuminated rings onto the corneal surface, which are reflected back into the instrument. The computer analyzes the reflected rings of light and a topographical map of the cornea is generated. The topographical map and computerized analysis reveals nay distortions of the cornea, such as in keratoconus or corneal scarring, as well as the corneal curvature and meridians of astigmatism.
- Diagnostic lens fitting – Biomicroscopic evaluation of the fit relationship of the lens on the eye.
- Instructions in lens care and handling.
- Evaluation of patient response – Good Vision? Comfort problems? Is the eye surface still healthy?
- Follow up visits as needed to ensure long term, problem free contact lens use.
Of particular importance are yearly follow up visit to ensure continual eye health. Simply because a patient sees well, and has never had previous problems does not mean they will never have a contact lens related complication. Contact lens related eye infection occurs much more frequently than patients believe and can happen at any time, even after years of use.
Follow up visits entail a review of contact lens solutions and how they are used, and wearing schedule. Probably the most noteworthy contribution factor to contact lens related red eye are dirty lenses and contact lens over wear, especially sleeping in lenses. This cannot be blamed entirely on the patients. Patients need to be educated regarding proper care and handling of lenses. Ultimately, patients who cannot responsibly take care of their lenses should not be wearing contact lenses.
Contact lens evaluations require that the eye surface be evaluated with the biomicroscope for eye lid inflammation, meibomian gland dysfunction, and conjunctival injection. For contact lens wearers, the cornea must especially be assessed. The cornea is the part of the eye that is being covered by the contact lenses. This part of the eye is especially vulnerable to swelling, infection and inflammation secondary to contact lens use. The doctor should “stain” the eye with flourescein dye to highlight any abnormalities of the cornea and to evaluate tear film stability. Finally, eye lids should be everted to check for large bumps. These bumps, called giant papillary conjunctivitis, develop over time usually because of deposits built up on the contact lenses. If these bumps become large or inflamed, contact lens use becomes uncomfortable and patients are no longer able to wear lenses.
