Scleral Contact Lenses

What is a Scleral Lens?

Scleral contacts are large diameter, gas permeable lenses that are designed to vault over the entire cornea (clear covering of the front of the eye) and rest on the sclera (white part of eye). This allows them to essentially replace the corneal surface with a perfectly smooth optical surface making them a perfect option for people with irregular corneas. In addition, the vaulted space between the cornea and the contact lens is filled with artificial tears or non-preserved saline which acts as a fluid reservoir which can provide comfort to people with severe dry eyes who otherwise could not tolerate contact lens use.

Conditions treated

Scleral lenses can be used to treat the typical causes of blurred vision but are most often used in the correction of irregular corneas due to a variety of conditions. These may include:

Keratoconus
Post-Operative Corneal Transplant
Pellucid's Marginal Degeneration
Severe Dry Eye Disease
- Sjogren's Syndrome
- Graft-vs-Host Disease (GVHD)
- Stevens-Johnson Syndrome
Corneal Scarring

The list of conditions treated with scleral lenses continues to grow with improvements in lens designs and technology.

Why Scleral Contacts?

There are several advantages of scleral contact lenses over traditional small diameter gas permeable lenses.

Comfort: RGPs rest on the cornea, the most sensitive tissue of the eye. As the eye blinks, the lens moves on the eye. If there is too much movement, discomfort and intolerance to the lens will develop. Because scleral lenses are designed to vault the corneal surface and rest on the less sensitive surface of the sclera, they are more comfortable.

Centration: In cases of early disease or mild irregularity, RGPs may provide adequate vision and comfort, however if the smaller diameter lens does not center properly on the eye or moves excessively with blinking, it will cause discomfort and variable vision. Switching to a large-diameter lens may solve this problem.

Stability: Scleral lenses are designed to fit with little or no lens movement during blinks, making them more stable on the eye compared to traditional RGPs.

Types of Scleral Lenses

Scleral lenses are larger than their standard gas permeable counterparts. A typical RGP lens is usually 8-10 mm in diameter. In comparison, sclerals usually start around 13 mm and can be made as large as 24 mm. This large range of sizes allows for more or less vaulting of the corneal surface, and for improved comfort and stability of the lens while it is worn.

Corneo-Scleral: These lenses are usually 13-15mm in diameter. They provide improved comfort and stability over standard RGPs, however may not be large enough to treat more advanced disease.

Mini-Scleral: Typcialy 15-18mm in diameter, these lenses provide the ability to vault more significant irregularities and are the more common size to treat mild to moderate stages of disease.

Scleral: >18mm in diameter. The largest sizes of scleral lenses are used for more advanced conditions as they may require the ability to vault large changes in corneal curvature or hold a larger tear reservoir.

While larger lenses allow for treatment of more advanced disease, they are more difficult to insert and remove and may be more costly. During your consultation, the doctor will discuss all options and will help determine the best option for your specific needs.

Process

Scleral contacts are custom designed for each person so the fitting demands greater expertise and often significantly more time than fitting standard soft or gas permeable lenses.

The process of fitting begins with a consultation with our doctor to determine the underlying problem and its severity, discuss previous treatment efforts and their successes or failures and to review the pros and cons of other potential treatments. If it is determined that a scleral lens fitting is appropriate, a follow up scleral lens fitting appointment will be scheduled.

At the fitting, the doctor will insert lenses of different sizes and curvatures to determine the lens which provides the appropriate clearance and stability on your eye. Your vision will then be checked to determine the correct lens power. This information will be used to design and manufacture a custom scleral lens for you.