Recently, the first scleral lens was cleared by the U.S. Food and Drug Administration (FDA) for the management of ocular surface disease to include dry eye syndrome. And, when it is prescribed for such, it is also indicated for the correction of refractive errors such as presbyopia. Surely, other brands will be seeking and receiving a similar blessing from the FDA in the near future.
Although many fitters have been prescribing scleral lenses for dry eye syndrome as an off-label use, this FDA clearance does provide us with the ability to more openly discuss this option with those who could potentially achieve both ocular and visual benefit.
Lots of Opportunity
Scleral lens manufacturers have been quite vocal in denoting the “regular” rather than “irregular” cornea as the next frontier for their products. This is understandable, as the potential market numbers are staggering. The Tear Film & Ocular Surface Society (TFOS) Dry Eye WorkShop (DEWS I) epidemiology data estimated that almost 5 million Americans aged 50 years and older have dry eye (TFOS, 2007). Approximately two-thirds of these are women, which also correlates closely with the percentage wearing contact lenses.
Possibly, the recent results from DEWS II will provide an even more accurate picture of the number of patients in the United States suffering from dry eye. Additionally, that report will provide us with an updated definition of this condition. The new definition of dry eye is as follows: “Dry eye is a multifactorial disease of the ocular surface characterized by a loss of homeostasis of the tear film, and accompanied by ocular symptoms, in which tear film instability and hyperosmolarity, ocular surface inflammation and damage, and neurosensory abnormalities play etiological roles” (TFOS, 2017).
Making Sense of the News
So, what does this mean for eye-care practitioners and their patients from a clinical perspective?
First, it’s expected that we’ll have many more presbyopic scleral lens options available. Up until now, multifocal/bifocal scleral designs have been viewed mostly as an afterthought by lens manufacturers, mainly because of their focus on refining the designs to solve the complex fitting issues of the irregular cornea. And, they’ve done a great job in that the success rate is extremely high with these lenses.
The next step is determining multifocal optics that are ideal for how the scleral lens will fit a normal-topography (albeit dry) ocular surface. It’s understood that these lenses will decenter on almost all eyes, more so than any other contact lens. It’s also understood that this decentration will most likely result in the misalignment of the optics. Thus, creative design concepts not presently in use will be necessary to solve this.
Second, it’s possible that there will be insurance reimbursement for these patients—depending on their carrier—that wouldn’t be possible with a soft or corneal GP lens.
In these cases, documentation is vital. Of course, there is the clinical evaluation made up of tests such as corneal and conjunctival epithelium staining (with fluorescein, lissamine green, or rose bengal), tear film osmolarity, ocular surface matrix metalloproteinase-9, tear breakup time, Schirmer’s, tear meniscus height, and others.
Additionally, one or more of the dry eye questionnaires are helpful. There’s too many to list here, but commonly used ones include the Ocular Surface Disease Index (OSDI), Contact Lens Dry Eye Questionnaire (CLDEQ), McMonnies Questionnaire (MQ), Subjective Evaluation of Symptoms of Dryness (SESoD), and Standard Patient Evaluation of Eye Dryness (SPEED).
A new dry eye indication for scleral lenses, combined with new multifocal optics, could be very beneficial to patients and practitioners alike. CLS
For references, please visit www.clspectrum.com/references and click on document #260.