Dr. Jaynes' Advanced Training
Dr. Jared M. Jaynes OD, FAAO completed his advanced training in medically necessary contact lenses and irregular corneas at the Southern California College of Optometry. His contact lens concentration includes scleral gas permeable lenses for anterior segment pathology, such as, keratoconus, dry eye syndrome, post-corneal transplant irregularities, exposure keratopathy, and post-surgical ectasias. Dr. Jaynes has fit hundreds of patients in medically necessary contact lenses of different types.
Definition of Medically Necessary Contact Lenses
There are many different types of medically necessary contact lenses (MNCLs). Often times, MNCLs provide improved vision that otherwise would not be possible with glasses or standard / cosmetic contact lenses. Medically necessary contact lenses are considered medical devices and differ from regular or “cosmetic” contact lens designs. Cosmetic lenses are elective and are not covered by health insurance. Medical contact lenses are custom to each patient, are associated with a covered medical diagnosis, and may be covered by your insurance. One specific type of MNCL is a scleral contact lens.
What are Scleral Lenses?
Scleral lenses are large-diameter gas permeable lenses. They can range from 14 mm to over 20 mm in diameter. They are called “scleral” lenses because they completely cover the cornea (the clear dome of tissue that covers the colored part of the eye) and extend onto the sclera (the white part of the eye that forms the outer wall of the eye).
Why are Scleral Lenses Useful?
Scleral lenses offer certain advantages over corneal lenses (traditional “gas permeable” lenses).
- Comfort. Scleral lenses are more comfortable than corneal lenses. The cornea is one of the most highly sensitive tissues in the body. The conjunctiva (soft, clear tissue that lies over the sclera) is much less sensitive than the cornea. Scleral lenses rest primarily on the conjunctiva and induce less lens sensation than smaller lenses that rest upon the cornea.
- Protection. Scleral lenses trap a reservoir of fluid behind the lens. This fluid protects the cornea, and may even allow it to heal in some cases (ex: severe dry eye syndrome). In addition, this layer of fluid improves the patient’s vision.
- Stability. Corneal lenses can be unstable and move with each blink, especially in patients with corneal diseases. Scleral lenses extend under the upper and lower lids and move minimally with each blink. A stable lens offers more stable vision and a more comfortable fit.
Who Could Potentially Benefit from Scleral Lenses?
Patients with irregular corneas (keratoconus, post-transplants, corneal ectasias), patients with conditions that affect the tear film (dry eye syndrome, graft vs. host disease, Sjogren’s syndrome, Stevens Johnson syndrome, and neurotrophic keratopathy), and patients with refractive error (nearsightedness, farsightedness, or astigmatism) who are unable to wear other forms of correction could benefit from scleral lenses.
How Do They Work?
For patients with irregular corneas: If the cornea is not smooth, vision will not be easily correctable with spectacles or soft contact lenses. Scleral lenses mask this irregularity and allow for clearer vision by providing a smooth front surface through which light can enter the eye.
For patients with tear film insufficiencies: Some patients have disorders that affect the quality or quantity of tears that help to keep the eye’s surface smooth and healthy. The fluid reservoir trapped beneath a scleral lens may improve comfort for these patients, and may allow the corneal surface to heal.
Are Scleral Lenses New?
Scleral lenses were actually the first contact lenses described in medical literature in the late 1800’s. However, due to manufacturing challenges and because of the lack of oxygen transmission through early lenses, scleral lenses did not become popular at that time.
Now there are “breathable” materials that minimize problems caused by lack of oxygen to the cornea. Improved designs and manufacturing processes have made it easier to fit and prescribe scleral lenses.
What to Expect
The medical contact lens fitting process is different for every unique patient. The typical patient will need SEVERAL visits consisting of a complete eye exam, a contact lens fitting appointment, a contact lens dispensing visit, application and removal training, and subsequent visits monitoring your ocular disease in the presence of the medical contact lens.
The goal of medical contact lenses is to optimally correct your vision while providing good tolerance and several hours of comfortable wear per day with your lens. However, this needs to be achieved while maintaining the health of your eyes in the presence of the contact lens. Every effort will be made to attain these goals without the use of other optical correction (such as glasses). There are times when we cannot accomplish all of these goals and need to incorporate glasses over your medical contact lenses, change contact lens designs completely, or discontinue the fitting process altogether.