SCLERAL LENSES: Sometimes Bigger is Better
If you've been told that you cannot wear contact lenses, ask us for a second opinion and consider scleral contact lenses. We are one of the few optometry clinics in Saskatoon specializing in contact lenses for high prescriptions and abnormal corneas.
On this page, you will find information about:
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The cost of scleral lenses
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Types of scleral lenses
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Conditions that benefit from scleral lenses
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The scleral lens fitting process
COST OF SCLERAL LENSES
Scleral contact lenses are custom-made for you. Fitting scleral contact lenses demands more extraordinary expertise and time than fitting standard soft or GP contact lenses. Your eye doctor may need you to try several lenses of different sizes and shapes during the fitting process. Computerized instruments are used to measure how the lens fits your eye. It's normal for specific lens parameters to be modified after trying your custom lenses. The process may require several lenses to be made and exchanged for you. It all depends on the complexity of your eye and how your eye tolerates the lens. Adjustments of lens parameters may be needed, and if so, additional lenses are made and exchanged. The entire scleral lens fitting process takes several eye doctor appointments to determine the optimal lens for each eye.
Many people that use scleral lenses have worn soft contacts or corneal RGP lenses in the past. However, the process of applying and removing scleral lenses may take some practice. The additional time needed to master scleral lens insertion due to the large size of the lenses and the fluid reservoir beneath the lens needs to be considered during the fitting process. Your eye doctor will coach you on inserting and removing the lenses before you take your lenses home. Here is a helpful video to teach you how to insert and remove scleral contact lenses.
Sometimes the fitting fees and cost of scleral lenses can be covered by your third-party medical insurance. Because scleral lenses are used for medical reasons, coverage comes out of the extended health benefits part of your insurance and not your vision care coverage. It is helpful to contact your insurance provider directly to find out if you have coverage for scleral lenses. Sometimes your insurance company requires more documentation to determine your coverage for scleral lenses. In that case, we're happy to help in any way we can!
HOW DO SCLERAL LENSES WORK?
Scleral contacts are large-diameter rigid gas permeable (RGP) contact lenses. These lenses are specially designed to rest on the "white" of the eye (sclera) and completely vault over your cornea. Vaulting your cornea is ideal if you have a condition such as keratoconus or a previous corneal transplant. Scleral lenses, in a sense, replace your irregular cornea with a perfectly smooth optical surface. The perfectly smooth contact lens surface corrects very high prescriptions and vision problems caused by keratoconus or other corneal illnesses. Even when a person cannot see clearly with glasses, a scleral contact lens can provide clear vision.
People that suffer from dry eyes after LASIK surgery get relief with scleral lenses, especially when eye drops alone are not enough. Underneath the scleral lens, there is a fluid reservoir between the cornea and the back surface of the contact lens. Bathing the cornea with fluid provides comfort for people with severe dry eyes who otherwise could not tolerate contact lens wear. If you suffer from other causes of dry eye, scleral lenses can also be helpful.
TYPES OF SCLERAL LENSES
Scleral contacts are much larger than standard corneal gas permeable (GP) contacts. They have a diameter similar to soft contact lenses. The smallest scleral contact lenses are approximately 14.5 mm in diameter, and the largest can be up to 24 mm. Your eye doctor completely customizes the lenses for you and will choose the best diameter for you based on your needs.
Formally, scleral lenses that are 18 mm or smaller are considered "mini-sclerals." On average human cornea is 11.8 millimetres in diameter. Even the smallest scleral lenses are designed to cover your entire corneal surface. In contrast, most conventional RGP contact lenses are 9.0 to 9.5 mm in diameter, so they only partially cover the cornea surface.
The third category of scleral lenses bridges the size gap between standard RGP lenses and mini-sclerals. These "corneoscleral lenses" are typically 13 to 15 mm in diameter. Corneo-scleral lenses often are recommended for people who require larger-than-normal RGP lenses for greater comfort. They also are beneficial when contact lenses are needed after laser eye surgery to correct irregular astigmatism caused by surgery.
As a rule, your eye doctor chooses the lens size based on the complexity of your condition. More mild forms of keratoconus, irregular astigmatism, corneal transplants, or laser refractive surgery are easily managed with corneoscleral or mini-scleral lenses. We prefer corneoscleral and mini-scleral contacts because they are easier for you to insert and remove, less expensive, and require fewer care solutions.
More complex conditions, including advanced keratoconus, severe dry eyes or ocular surface disease, require a large tear reservoir. Large-diameter full-scleral lenses are used to create a giant tear reservoir. They have more capacity to hold fluid and bridge significant changes in corneal curvature.
Your eye doctor will determine the best scleral lens type and size for your specific needs during your contact lens fitting process.
SCLERAL LENSES FOR KERATOCONUS
Our eye doctors recommend scleral contact lenses for various hard-to-fit eyes, including eyes with keratoconus. Because of the way scleral lenses are fit, they can optically correct the distortion caused by keratoconus and provide near-perfect vision in the majority of cases.
In cases of early keratoconus, your eye doctor may use a standard corneal RGP lens. However, the lens fit must be perfect. There is a possibility that a suboptimal lens could make your cornea progress and scar. Additionally, switching to a scleral contact lens may solve the problem if the contact lens does not center correctly on the eye or moves excessively with blinks and causes discomfort.
OTHER USES FOR SCLERAL LENSES
In addition to keratoconus, scleral contact lenses are used for people that have undergone a cornea transplant or for people with severe dry eyes. People living with Sjogren's syndrome, graft-versus-host disease, and Stevens-Johnson syndrome also benefit from scleral lenses. Advances in lens design technology allow eye doctors to design scleral lenses that can correct more conditions than ever before. Scleral lenses can correct near and far vision for those who need bifocals or progressive lenses in glasses.
Special-Effect Scleral Contacts
The term scleral lens also is used to describe cosmetic/costume contact lenses. However, costume contact lenses (also called theatrical contacts or Hallowe'en contacts) are soft lenses that bear little similarity to scleral gas permeable contact lenses. Theatrical contacts usually are for cosmetic purposes only and not for vision correction. Check out our blog post about Hallowe'en contact lenses.
Hopefully, this page can get you thinking about scleral lenses. If you are interested to know if you're a candidate for scleral contact lenses, book a free specialty contact lens consultation here. Our certified eye doctors are happy to answer any questions and give you more information.