Successful contact lens wear is achieved when three criteria are met: clear vision, comfortable lens wear, and good physiological response. It is widely recognized that the leading cause of contact lens dropout is failure to achieve comfortable lens wear. Achieving contact lens comfort can be even more elusive when managing presbyopes, who have a higher incidence of dry eye disease (Moss et al, 2008). This alone can lead to discomfort, but dryness can promote lens surface deposits, which can further exacerbate problems.
Before fitting any patient with contact lens correction, be sure to first look for symptoms and signs suggestive of ocular surface disease. Every evaluation should include, at minimum, an assessment of subjective complaints, tear quality, tear quantity, and ocular surface inflammation.
Subjective Questionnaires A number of subjective questionnaires are currently available, and studies have shown that they can all be useful (Simpson et al, 2008). The Tear Film and Ocular Surface Society’s (TFOS) Dry Eye Workshop II (DEWS II) report recommends employing either the Ocular Surface Disease Index (OSDI), due to its well established use record, or the Dry Eye Questionnaire (DEQ)-5, due to its brevity and “discriminative ability” (Wolffsohn et al, 2017).
Tear Quality The most frequently employed method of evaluating tear film stability is measurement of tear film breakup time (TBUT). While this is often performed by introducing fluorescein into the tear film, is it preferable to use less invasive techniques such as videokeratoscope imaging. It is best to perform the assessment before introducing drops or measuring tools into the tear film or manipulating the eyelids.
Tear Quantity A number of approaches can help us ascertain tear quantity or volume. These include analysis of the tear meniscus height (meniscometry), Schirmer’s test, and the phenol red thread test. The DEWS II report recommends that meniscometry be used as a routine diagnostic test of tear volume due to its non-invasive nature and reasonably good reliability (Wolffsohn et al, 2017). In cases in which severe aqueous deficiency is suspected, employ the Schirmer’s test without anesthetic.
Ocular Surface Inflammation Ocular surface inflammation can arise from a variety of etiologies, including dryness. While techniques are available to identify inflammatory markers in the tear film, a simple starting point is to look for conjunctival redness.
Contact Lens Approach
Proactively treating ocular surface disease will certainly help patients achieve success with contact lens wear. However, many of these patients will continue to coat lenses with deposits.
Switching contact lens care systems from a multipurpose care system to a hydrogen peroxide care system may help. However, at least one study has reported the comfort of daily disposable lenses to be superior to that of contact lenses cared for with either of these systems (de la Jara et al, 2013). There is evidence that both multipurpose and hydrogen peroxide-based lens care systems can lead to increased surface roughness (Lira, 2014), suggesting that improved comfort with daily disposable lenses may be due to a smoother lens surface.
A New Paradigm
Gone are the days when patients presented with symptoms of lens-related dryness and we switched contact lens materials, hoping to find one that helps. The new standard is to look for ocular surface disease, treat it when present, and then choose the best contact lens option. For many patients, including those in our presbyopic population, a daily disposable soft lens will be the answer. CLS
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