Scleral Contact Lens
The cornea is the transparent dome-shaped front part of our eyes and its most important focusing lens. Like the lens of a camera, its surface must be perfectly smooth in order to provide clear vision.
When disease or injury causes the corneal surface to become irregular, the eye can no longer focus clearly, even with the strongest glasses. Rigid Gas Permeable contact lenses have the unique ability to improve the vision of these eyes by creating a smooth layer of tears that mask the irregular surface of the cornea. However, there are many eyes with damaged corneas that cannot be fitted with a Rigid Gas Permeable contact lens.
Moreover, the corneas of patients who suffer from severe ocular surface disease become so exquisitely fragile that they are often unable to withstand the pressure of a blink or the briefest exposure to air—let alone the friction of a Rigid Gas Permeable contact lens. Unlike conventional contact lenses, this device, about the size of a 10 cent coin, rests on the relatively insensitive white sclera of the eye and creates a space over the cornea that is filled with artificial tears.
By masking the irregular surface of the damaged cornea, this lens device can be helpful in improving vision in eyes with extremely distorted corneas. Moreover, this fluid compartment becomes a liquid bandage that protects the raw and sensitive cornea from exposure to air and the rubbing effects of blinking. This therapeutic environment nurtures healing and can virtually eliminate pain and photosensitivity.
It is this unique liquid bandage that is responsible for the “miracle” experienced by our patients. One of the principal reasons for the success of the Scleral Lens is its highly oxygen-porous plastic, that allows the cornea to breathe through the lens. This was first described by Don Ezekiel in 1983 at The British Contact Lens Conference in Harrogate. This is essential since the cornea, unlike any other surface tissue of the human body breathes by extracting oxygen from the surrounding air rather than from the blood circulation.
Patients whose vision is impaired by damage to their corneas and who cannot be fitted with conventional rigid contact lenses are potential candidates for Gas Permeable Scleral lenses. (Unfortunately, contact lenses cannot help people who are suffering from retinal problems, such as macular degeneration.)
Our patients fall into two categories:
Those for whom the Scleral contact lens is their only option for recovering functional vision.
This includes, among others:
- Stevens-Johnson syndrome and related conditions such as TEN, chemical and burn injuries to the eye, ocular pemphigoid, aniridia, etc.
- Anesthetic cornea that may result from acoustic neuroma surgery, surgery for trigeminal neuralgia, birth defects such as dysautonomia and Seckle’s syndrome, herpes simplex/zoster of the cornea, diabetes, etc
- Pellucid corneal degeneration
- Terrien’s marginal degeneration
- Severe dry eyes
- Graft vs Host Disease
Those for whom corneal transplant surgery is an option.
This includes, among others:
- Injuries leading to scars
Following unsuccessful corneal surgery such as:
- Radial keratotomy
- Laser Refractive Surgery. (Lasik,Lasek, PRK)
- Corneal transplants in which the healing resulted in warpage of the graft and abnormal astigmatism
- Scars due to disease and certain dystrophies and degenerations