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    5 reasons ODs don’t fit toric contact lenses

    Here’s why these reasons no longer resonate

     

    3. Variability in fit (includes rotation)

    When fitting contact lenses, learn to discern who are the best candidates.

    Beyond patient personal hygiene and visual demands, there are considerations specific to astigmats. Young and colleagues discovered that lens orientation and stability was most dependent on the degree of myopia (the lower the myopia, the more stable the lens), palpebral aperture (the smaller, the more stable), and lens tightness (the looser, the less stable).8

    While a high myope with large palpebral apertures and steep K values may not be the ideal toric contact lens candidate, knowing this will help you set patient expectations and your expectations for chair time.

    Improvements in toric lens designs have also come a long way in providing improved visual stability. In a February 2017 study, there was no significant difference of retention rate of low vs. high cylindrical prescriptions, possibly indicating new toric lens designs are able to provide more visual stability for patients.9

    Related: Educate your patients about astigmatism

    4. Lens comfort

    Discomfort is the prevailing reason for contact lens dropout and should be addressed in toric contact lens wearers like it would be in all lens modalities.

    While clinically I have had patients report differences in comfort of lenses when one eye wears a spherical lens and the other a toric (typically when a toric is a prism-ballast design and the patient feels the increased lens thickness), research has shown there is no significant difference in the rate of discomfort between spherical and toric wearers in neophyte contact lens dropouts.8

    When a patient reports comfort in her prescribed lenses one year but not the next, the contact lenses didn’t change, but most likely her ocular surface health did.

    You will be a more successful contact lens clinician the more proactively you treat deficiencies in the ocular surface. The 2012 Tear Film and Ocular Surface Society (TFOS) International Workshop on Contact Lens Discomfort report found tear film stability to be a key factor in lens comfort.10 With 86 percent of dry eye involving meibomian gland dysfunction (MGD),11 a regular assessment of a patient’s meibomian gland expression is critical in any contact lens evaluation. If MGD is not the culprit, a thorough case history involving current or new medication, changes in health history, or changes in environment may reveal other extrinsic factors.

    Related: Using tinted contact lenses in practice

    5. Power limitations

    I’ve been able to move many patients out of custom soft contact lens designs to more affordable, higher Dk options for the first time in years. This is due in part to the rollout of CooperVision’s Biofinity Toric XR, the only silicone hydrogel contact lens available from a major manufacturer beyond the traditional stock range.

    Lenses are available from ±10.00 D (in 0.50 D steps after ± 6.00 D) with cylinder powers from -2.75 D to -5.75 D (in 0.50 D steps) and an axis of 5 degrees to 180 degrees in 5-degree steps.

    I’m also excited about this year’s rollout of the highest Dk daily disposable toric lens with Johnson & Johnson Vision Care’s Acuvue Oasys 1-Day for Astigmatism, which includes 2260 parameters for coverage of 87 percent of eyes.12 Coverage ranges from +4.00 D to -9.00 D with up to -1.75 D astigmatism for both with- and against-the-rule prescriptions.

    Charissa Young, OD, FAAO
    Charissa D. Young, OD, FAAO, practices in Seattle, WA. Dr. Young is interested in dry eye and specialty contact lenses. She is involved ...

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