This eye condition causes the cornea to thin and bulge outwards, creating a cone-like shape. This irregular shape causes vision distortion and sensitivity to light. Keratoconus often begins during a person's teenage years and progresses until the mid-thirties. The exact cause is unknown. However, it likely results from genetic and environmental factors.
Symptoms of Keratoconus
The most common symptoms of keratoconus include:
Sensitivity to light
Frequent changes in eyeglass prescriptions
As the condition worsens, vision distortion increases. Without treatment, advanced keratoconus can lead to legal blindness.
An eye doctor can diagnose keratoconus through a slit lamp exam and other tests like corneal topography. This imaging maps the shape of the cornea, allowing the doctor to see any bulging or thinning. Doctors also measure corneal thickness. A healthy cornea ranges from 500 to 550 microns thick. The thinned areas are usually less than 400 microns thick in keratoconus patients.
In mild cases, eyeglasses or soft contact lenses provide sufficient vision correction. But as keratoconus progresses, rigid gas permeable (RGP) lenses are more effective. These hard contacts better match the irregular cornea shape. Advanced keratoconus often requires hybrid lenses. These have a soft skirt around a rigid center portion. The skirt enhances comfort without compromising visual acuity.
Understanding Scleral Lenses
Scleral lenses are one type of rigid gas-permeable lens. They cover not just the cornea but also part of the white of the eye. This makes them ideal for irregular corneas. The larger lens surface distributes pressure for improved comfort. Scleral lenses range from 14mm to 24mm in diameter. These larger lenses vault over more of the corneal surface, avoiding touch while protecting the fragile cornea.
Benefits of Scleral Lenses
Compared to RGP lenses, scleral lenses offer these advantages for keratoconus patients:
Improved comfort - The lens rests on the sclera rather than the sensitive cornea, reducing irritation and abrasions.
Better vision - The large lens provides stable, crisp vision by neutralizing corneal irregularities.
All-day wear - Patients can comfortably wear scleral lenses for extended periods.
Eye protection - The large lens shields the cornea from debris, wind, and drying out.
Customizable - Eye doctors can design scleral lenses to match each eye's unique topography perfectly.
The Fitting Process
Getting fitted for these lenses requires an experienced optometrist. Several office visits allow for fine-tuning of the lens design and fit. At the first appointment, the eye doctor examines the eyes and takes measurements. Highly precise scans map the cornea's shape.
The lab uses this data to manufacture custom lenses. These maximize vision while avoiding compression on the cone. At follow-up visits, the optometrist assesses the lens fit. They then make adjustments until the patient achieves optimal comfort and vision. They also teach proper insertion and removal of the lenses and provide ongoing care instructions.
Caring for Scleral Lenses
To prevent infections, proper cleaning of your lenses is essential. You should wash your hands thoroughly before handling your lenses. Also, weekly enzymatic cleaning removes protein buildup.
To disinfect the lenses daily, use a hydrogen peroxide system, which kills any microbes that could infect the eye. Before disinfecting, remove debris by rubbing and rinsing. If any redness, discharge, or pain occurs, the lenses must be removed immediately. Promptly reporting problems to an eye doctor prevents complications.
With diligent care, scleral lenses provide keratoconus patients with outstanding comfort and vision. Consult an optometrist to see if they are the best option for managing your irregular cornea.
For more on scleral lenses, visit Brookfield Eye Care at our office in Brookfield, Illinois. Call (708) 485-0411 to schedule an appointment today.