As proactive myopia management surges to the forefront of eye care, occasional obstacles to successful implementation in clinical practice must be addressed. Rather than become discouraged or give up, practitioners should prepare themselves with tools to overcome these roadblocks as they arise. As a reminder, the options discussed below involve off-label interventions for myopia progression.
While the presence of astigmatism can complicate myopia management, it should not exclude patients from being selected for treatment. When faced with a progressing young myope who has refractive astigmatism, practitioners should ask: How much astigmatism is present? Is any of it lenticular? Has the astigmatism been fully corrected previously?
In my experience, most children who have up to –1.25D of refractive astigmatism can achieve excellent visual acuity in spherical soft multifocals, so I generally do not hesitate to pursue this option for good candidates (Walline et al, 2013). However, patients wearing toric single-vision lenses tend to note subjective vision complaints more frequently when refit into spherical multifocals. In terms of using orthokeratology (ortho-k) for lower-to-moderate astigmatism, many designs are cleared by the U.S. Food and Drug Administration to temporarily correct up to –1.50D or –1.75D of astigmatism. However, corneal reshaping will generally only correct corneal astigmatism (Wen et al, 2015). For higher amounts of astigmatism, one commercially available multifocal toric lens is available in 5º increments and up to –5.75D of cylinder. Ortho-k can still be an option, but higher amounts of corneal astigmatism may warrant a toric reverse and/or alignment curve for optimal fitting.
Finally, low-dose atropine (such as 0.025%) is an evidence-based (but off-label) approach that can be used in combination with any optical correction (Cooper et al, 2018; Chia et al, 2016; Yam et al, 2019).
Note that soft multifocals, ortho-k, and low-dose atropine each carry the potential for subjective visual side effects. Fortunately, many children do not experience symptoms at all, and those who do generally report them to be mild and tolerable (Walline et al, 2013; Cooper et al, 2018). Practitioners new to myopia management should remember that the goal is to slow myopia progression, not to provide the same visual experience as with single-vision glasses or contact lenses. As such, when pursuing myopia control, a certain degree of mild visual trade-off may be acceptable if patients feel that any symptoms are tolerable and practitioners deem visual performance to be satisfactory. Practitioners should be comfortable answering questions such as “Is it normal to see halos at night when I stare at lights during lacrosse practice?” In most cases, patients and parents are simply looking for reassurance that this is normal rather than seeking resolution of the symptoms. On the other hand, when symptoms are intolerable or result in excessive visual compromise, there are options for enhancement.
When fitting soft multifocals, the most common complaints are glare or blurred distance vision relative to habitual correction. First, ensure that patients have worn the lenses long enough for neuro-adaptation to have taken place; assuming that this is the case, adding –0.25D to the distance power in each eye will often reduce the symptoms.
Similar complaints with ortho-k can often be addressed by confirming optimal lens centration with topography. If centration is optimal, consider enlarging the optical zone.
When prescribing low-dose atropine, remember that all concentrations induce some mydriasis and cycloplegia, introducing the possibility of visual side effects (Cooper et al, 2018). I generally prescribe photochromic progressive or anti-fatigue lenses to mitigate these side effects. For excessive symptoms, decrease the atropine concentration; however, if patients are consistently exhibiting significant cycloplegia or mydriasis, consider reaching out to your compounding pharmacy. CLS
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