Rigid Gas Permeable Lenses Seaview Eyecare

While soft contact lenses are the most common type of contact lenses worn by patients with normal, healthy eyes, they may not provide optimal vision and comfort for patients with unique prescriptions, corneal conditions or ocular health concerns. Typically, soft contact lenses can provide visual clarity at distance that is equivalent to visual clarity in eyeglasses. But patients that have sustained injuries, undergone corneal transplants or that have corneal irregularities may not see well with eyeglasses or soft contact lenses. Rigid contact lenses provide a customized solution to dramatically enhance the vision and lives of patients with special corneas.

The doctors at SeaView Eyecare have a passion for contact lenses, and we are especially committed to helping patients in need of specialty contact lens care. Below is a summary of some of the specialty rigid lenses that we design and fit at SeaView Eyecare.

Scleral Lenses

These larger contact lenses are made of a highly breathable rigid material and typically range in size from 13.0-19.0 mm in diameter. They land on the white sclera and vault over the sensitive cornea. The lenses are customized to optimize vision and fit for patients with corneal irregularities. Scleral lenses provide dramatically improved vision and comfort for patients that are unable to achieve sufficient vision through glasses or other contact lens types. They can also function as a moisture chamber for patients with severe dry eye and ocular pain. These lenses are typically replaced annually.

Anyone can wear Scleral lenses, but these lenses are generally excellent in managing conditions such as:

Corneal irregularities – caused by Keratoconus or surgical procedure
Dry eyes
Severe giant papillary conjunctivitis (GPC)
Severe refractive errors – astigmatism
Patients who are unable to wear soft contact lenses

What are scleral lenses?

These contact lenses are made of highly breathable gas permeable material that vault over the cornea. The lenses are custom made to help patients with corneal irregularities. Scleral lenses are made to be comfortable and to drastically improve vision for patients that are unable to sustain sufficient vision through glasses or soft contact lenses.

What Are The Benefits?

Scleral lenses are made to be more comfortable and stable because they are much larger compared to regular soft contact lenses. These lenses provide excellent clarity in vision. Patients that suffer from dry eyes can definitely benefit from these lenses. Scleral lenses create a liquid reservoir that the cornea sits in throughout the day. This provides comfort for patients with dry eyes.

Rigid Gas Permeable Corneal Lenses

These smaller contact lenses are made of a highly breathable rigid material and typically range in size from 6.0-11.0 mm in diameter. They sit on the cornea and glide over the surface of the eye with each blink. They provide superior vision for patients with irregular corneas, by providing a perfectly smooth front surface of the eye to focus vision. They provide the highest amount of oxygen permeability of any contact lens design available and can be used to treat a variety of visual disorders including large prescriptions, high amounts of astigmatism, dissimilar prescriptions between the two eyes, and corneal irregularity due to surgery, genetics, injury or scarring. These rigid lenses are sometimes “piggy-backed” on top of a soft contact lens for improved comfort. Rigid lenses are typically replaced annually.

Hybrid Lenses

These unique contact lenses have a rigid gas permeable corneal lens in the center and a peripheral soft contact lens skirt. The soft skirt improves comfort and helps to center the contact lens on the eye. The rigid center provides superior optics for improved vision. They are often prescribed for patients with irregular corneas or poor comfort with rigid corneal lenses. These lenses are typically replaced every six months.

Who Needs Rigid Gas Permeable Lenses?

1. Keratoconus

WHAT IS KERATOCONUS?
Keratoconus is a progressive vision disorder caused by the thinning and weakening of the cornea that results in an irregular protruding corneal shape. This bulging shape appears like a cone, giving the condition its name, resulting in distorted vision and significant visual impairment.

WHEN DOES IT START?
Keratoconus is generally first diagnosed at puberty and progresses through the mid-30’s before stabilizing. It can only be detected during a routine eye exam. To make a diagnosis, your eye doctor measures the curvature and thickness of the cornea to evaluate for thinning and irregularity in shape. Testing is non-invasive, simple and painless and can allow for earlier intervention and prevention of progression of the condition.

WHAT ARE THE CAUSES?
While the causes of keratoconus are not specifically known, a number of factors are known to be associated with it and there is a hereditary component to it.

Keratoconus is associated with:

Eye allergies (chronic eye inflammation)
Excessive eye rubbing
Ehlers-Danlos syndrome, Down syndrome, Retinitis Pigmentosa

WHAT ARE THE SYMPTOMS?
Keratoconus most often affects both eyes but symptoms may differ in each.

Mild blurry vision
Distorted vision that worsens with time
Sensitivity to glare and light
Frequent changes in eyeglass or contact lens prescriptions that do not fully clear vision

WHAT IS THE TREATMENT PLAN?
When Keratoconus is diagnosed, the first goal is to determine the stability of the condition. For younger patients at the greatest risk of progression (early teens through mid-thirties and pregnant adults), the first objective is to stop the corneal thinning that is causing the corneal irregularity. Preventing progression in early keratoconus patients can provide patients with the ability to maintain sufficiently clear vision with eyeglasses or soft contact lenses throughout their lives, rather than being restricted to rigid contact lens wear for functional vision.

Patients with keratoconus are monitored closely over a period of several months and are referred for a procedure called Corneal Crosslinking when progression is detected. This condition utilizes topical riboflavin drops, UV light, and oxygen to strengthen the cornea, preventing further progression.

Once a patient's corneas are deemed stable, an optometrist skilled in specialty contact lenses can fit the patient with customized lenses that provide sharper, more comfortable vision by compensating for the irregular shape of the cornea. It's important to note that contact lenses do not reshape the cornea or stabilize keratoconus. They only serve to provide improved vision when they are worn.

2. Severe Dry Eye (e.g., Sjögren’s Syndrome)

What is it?: A condition where the body’s immune system attacks the glands that produce tears, leading to dry, irritated eyes.
Why scleral lenses?: Since Scleral lenses are filled with a preservative-free saline, they create a consistent reservoir of fluid between the lens and the eye, which helps to keep the eye moist and provides relief from dryness.

3. Irregular Corneas:

What is it?: Scarring on the cornea caused by injury, infection, or surgery.
Why scleral lenses?: They can help by providing a smooth surface over the scarred cornea, improving vision and reducing discomfort.

Eyes with uneven or irregular surfaces, which can typically be caused by scarring post infections, abrasions, ulcers, injuries, etc.

4. Post-Corneal Transplant

What is it?: After a corneal transplant, the eye might have irregularities in shape or vision issues.
Why scleral lenses?: Like corneal scarring, Scleral lenses help improve visual acuity and comfort by creating a smooth surface over the transplanted cornea, which may be irregular.

5. High Prescription Needs

What is it?: Some patients with extremely high myopia (nearsightedness) or hyperopia (farsightedness) may not have good success with regular contact lenses or glasses.
Why scleral lenses?: The larger, custom-fitted design of scleral lenses can correct extreme prescriptions, often better than regular lenses