Scleral contact lenses are the most common and most successful treatment for patients with keratoconus, pellucid marginal degeneration, post corneal transplant, post-refractive surgery complications, irregular corneas and other conditions requiring a medically necessary contact lens.
What is a Scleral Contact Lens
A scleral contact lens is a little larger than a traditional soft contact lens and rests on the sclera. Scleral lenses vault over the entire cornea and then rests on the sclera on the other side of the eye. A scleral lens will usually extend only a couple of millimeters beyond the colored part of the eye. Patients wearing properly fit scleral contacts report the comfort is similar to a soft contact lens. Modern scleral contact lenses use the latest, highly oxygen permeable lens materials. These high tech lens materials allow the eye to get the oxygen it needs without any ill effects. At Total Eye Care, Dr. Richard Driscoll has found over 90% of his keratoconus patients prefer the new custom scleral contact lenses over their previous method of treatment.
The History of Scleral Contact Lenses
Scleral contact lenses have been around since the late 1800s when they were made of glass. Early scleral lenses were often referred to as scleral shells. In the early 1900s polymethylmethacrylate (PMMA), a type of plastic made the manufacturing process easier; however, it was still a cumbersome, hard to reproduce process. In the 1940s scleral lenses fell out of favor with the advent of “hard lenses”, using PMMA, which incorporated new manufacturing techniques, allowing the contact lenses to be made smaller giving rise to better comfort and longer wearing times.
Small Gas Permeable Lenses Outpace Scleral Contact Lenses
Further material advancements in the 1970s led to the development of gas permeable contact lenses (often referred to as RGP lenses) and soft contact lenses (SCL). Gas permeable lenses and soft contact lenses are still used today with soft contact lenses being by far the most popular option. Soft contact lenses; however, are a poor option for patients with irregular corneas. Gas permeable lenses, on the other hand, are often a good option for patients with keratoconus or irregular corneas.
New Lens Materials and High Technology Manufacturing Put Scleral Contact Lenses at The Forefront of Keratoconus Treatment
Highly oxygen permeable materials, new manufacturing techniques, and computer-aided design have led to scleral contact lenses that are more comfortable, give better vision and are safe for the eye. In the past 5 to 10 years, those of us that see a lot of patients with keratoconus have shifted our focus to using scleral contact lenses as the treatment choice for keratoconus.
Scleral Contact Lenses, The Best Option for Patients with Keratoconus or Irregular Corneas
Our patients report comfort is the number one feature they like about their scleral contact lenses. During the fitting process, we always survey our patients about how the lenses feel in their eyes. The most common responses are they feel fine or I can’t feel them at all. If a patient does report feeling the lenses we can make changes in the fit to improve the lens comfort.
Better vision also makes scleral contact lenses a better choice for treating keratoconus and irregular corneas. At Total Eye Care, our keratoconus specialists use lenses that allow the doctor to fully customize the lens for optimal vision. Since scleral contact lenses move very little on the eye they provide more stable vision than other lenses.
Better Quality of Life
Virtually all patients with keratoconus see better with contact lenses than with glasses. It is not uncommon for patients to see 20/200 with glasses; however, with scleral contact lenses, their vision may improve to 20/30 or even 20/20. We have seen cases where patients were able to get a better job because they can now see better. Many patients that have not experienced scleral contact lenses are unable to drive because of poor vision. However, with scleral contact lenses they can now see well enough they feel comfortable driving again.
Why Do Scleral Contact Lenses Provide Better Vision Than Glasses or Traditional Contact Lenses?
A layer of tears sits between the scleral lens and the cornea. This layer of tears fills in the corneal irregularities making a smoother optical surface. By smoothing the optical surface we reduce irregular astigmatism and other optical aberrations, providing better visual acuity.
What Conditions are treated with Scleral Contact Lenses?
Anyone can wear scleral contact lenses; however, because they are difficult to fit they are usually reserved for special cases. Keratoconus is the most common use for fitting scleral contact lenses and refractive surgery complications are the second. Here is a list of the common uses for scleral contact lenses.
- Refractive Surgery Complications (PRK, LASIK, etc.)
- Dry Syndrome
- Pellucid Marginal Degeneration
- Irregular Astigmatism
- Penetrating Keratoplasty (corneal transplant)
- Post Surgical Ectasia
- High Myopia
What Makes Scleral Contact Lenses so Comfortable?
The simple answer is the size of a scleral lens makes it more comfortable than a traditional gas permeable contact lens, however; there is a little more to it than that. A traditional contact lens is much smaller, typical 9 to 10 mm in diameter and the entire weight of the lens rests on the cornea. The human cornea is one the most highly innervated, sensitive pieces of tissue on the body. With each blink, this small contact lens moves a few millimeters over the cornea and the lid will often have to roll over the edge of the lens as well. All of these factors can cause some degree of discomfort. Over time people get used to this sensation and can wear the lens all day.
On the other hand, the weight of a scleral lens rests on the sclera (the white part of the eye). Being much larger it spreads its weight over a much greater, less sensitive area. The edge of a scleral contact lens rests under the upper eyelid so when you blink the eyelid doesn’t catch the edge of the lens. There is also very little movement of the lens when you blink, this not only improves comfort but makes for more stable vision.
Why are Scleral Contact Lenses a Better Option for Treating Keratoconus?
From an eye physiology standpoint, both rigid gas permeable lenses and scleral lenses allow they eye to receive sufficient oxygen. In almost all cases; however, scleral contact lenses provide improved comfort and better more stable vision than traditional gas permeable lenses. Scleral contact lenses also provide better visual acuity, durability, and comfort than hybrid lenses such as the Synergeyes lenses. Keratoconus experts now agree scleral contact lenses are the treatment of choice for patients with keratoconus and irregular corneas.
What is the Process for Getting Scleral Contact Lenses at Total Eye Care?
A Comprehensive Eye Exam is an Important First Step
You can schedule an appointment online or by calling 817.416.0333. If you are ready to proceed then the next step is for us to conduct a complete eye exam. Making a determination of your best-corrected visual acuity is helpful in assessing the quality of vision you achieve with conventional vision correction such as glasses. Evaluating you ocular health also allows us to rule out other potential issues that may also affect your vision. Finally, discussing the result of our findings along with a review of the potential treatment options lets us put together a plan of action to help you recover the most vision.
Therapeutic Contact Lens Evaluation
When you return for your therapeutic contact lens evaluation we will make a topographical map of your cornea and conduct a few other tests to evaluate your cornea health. This initial information is important, allowing us to establish a baseline, and to monitor the health and stability or progression of your cornea. We will select an initial diagnostic lens from the data collected and place the scleral lens on your eye. Once we have verified the diagnostic lens will provide an optimal starting point we will have you rest with the lens in our eye for about 60 minutes. After the stabilization period, we will then check the fit and vision with the lens to optimize your comfort and vision.
With this information, your keratoconus specialist will design a custom scleral contact lenses. Each scleral lens is custom manufactured and takes at least 15 to 20 days to design, manufacture, and ship.
Test Driving Your New Scleral Contact Lenses
When we receive your new scleral contact lenses we will call you to schedule a time to teach you how to insert, remove, and care for your lenses. We will also schedule an appointment with the doctor to verify your new lenses are performing optimally.
I Have Had Corneal Cross-linking, Will a Scleral Contact Lens Help Me?
Yes, corneal cross-linking, sometimes called CR3, stabilizes the keratoconus. You still have keratoconus but the cross-linking strengthens the cornea, making a smoother optical surface. Once the cornea is stable we then proceed with fitting your scleral contact lenses, improving your visual acuity and function.
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Published online 2015 Oct 28. doi: 10.2147/OPTH.S52483