Keratoconus (keh-rah-toe-cone-us) is a condition in which the structure of the cornea isn’t strong enough to maintain a healthy ball shape, causing the cornea to bulge outward into a shape resembling a cone. This leads to a host of symptoms, including blurred and double vision, as well as halos around objects and streaks of light.
Below you’ll learn more about this condition and discover how Dr. David Yoo & Dr. Daniel Quon at Specialty Contact Lens Center at South Coast Optometry can treat your keratoconus to safeguard your eye health.
What is Keratoconus?
Keratoconus is a progressive eye disease in which the dome-shaped cornea thins, causing the cornea to develop a cone-like shape.
Astigmatism is common in keratoconus with other symptoms of blurry vision, glare, halos, ghost images, streaks of light, and night vision problems which usually cannot be corrected by traditional glasses and soft contact lenses in the moderate to advanced stages of keratoconus.
This rare eye condition affects 1 out of every 2,000 people. It typically begins in the teenage years and early 20s, with vision deteriorating over a period of about 10 to 20 years. It’s common for people with this disease to see prescription changes with each eye exam.
Keratoconus often runs in families, so if you or your children are at risk or are experiencing any of the symptoms mentioned below, contact Specialty Contact Lens Center at South Coast Optometry for an eye exam. Keratoconus can only be diagnosed through a thorough eye exam, where Dr. David Yoo & Dr. Daniel Quon will examine your cornea and measure its curvature.
What Causes Keratoconus
Your cornea is held in place by very small collagen fibers. When they are weakened, they cannot preserve the round shape of your cornea. The exact cause of keratoconus, however, is still unknown.
Weakening of the cornea tends to happen in those with a genetic predisposition, which is why keratoconus may affect several people in a single family.
Recent studies, however, have isolated genes correlated with keratoconus which has been favoring genetics as a large component to this corneal condition [2,4]. Keratoconus is usually seen in the teenage years and early 20s. Rarely will it present itself in the 35-year-old and older age groups? Many syndromes have been associated with keratoconus such as down syndrome, Leber congenital amaurosis, and connective tissue disorders .
Keratoconus has also been linked to:
- Excessive exposure to UV rays
- Excessive eye rubbing
- Difficulty wearing contact lenses
- Certain eye injuries
- Retinitis pigmentosa
- Marfan syndrome
- Ehlers-Danlos syndrome
Symptoms of Keratoconus
As the shape of your cornea begins to bulge, it alters your eyesight. Your normally smooth corneal surface becomes wavy and expands, becoming cone-shaped. This causes irregular astigmatism or nearsightedness. The condition tends to begin in one eye and later develops in the other eye as well.
Typically, one’s prescription will change frequently as vision worsens, and it will become difficult to wear contact lenses due to the expanding cornea. If the lenses are not properly fitted on someone with Keratoconus, the lenses can rub against the diseased part of the cornea. The excessive rubbing causes symptoms to worsen by aggravating the already thin cornea. When the symptoms of keratoconus intensify, the cornea can begin to swell and form scar tissue. This scar tissue can result in even more visual distortion and blurred vision.
Symptoms during the early stages of keratoconus:
- Mild blurred vision
- Slightly distorted vision (straight lines appear bent or wavy)
- Some sensitivity to light and glare
- Red-eye and/or swelling
- Chronically irritated eyes
In its later stages, one tends to experience:
- Increased blurred and distorted vision
- Nearsightedness or irregular astigmatism
- Inability to wear regular contact lenses
There are several ways to treat this condition. When the symptoms are still mild, you can correct your vision using eyeglasses. As the condition progresses, there are several treatment options.
Corneal topography is crucial in diagnosing and tracking the progression of keratoconus . A corneal topographer takes an image then calculates and determines the shape and contour of the corneal surface. After analyzing the data provided by the topographer, we can then begin the journey to better vision.
There have been many advancements in technology to aid patients who suffer from keratoconus. With these advancements, specialty contact lenses (ie. a scleral lens) are a preferred choice for better and improved vision . Under circumstances where the cornea continues to progress, corneal cross-linking may be an option; ultimately, if there is no stability a corneal transplant may be warranted. However, studies have shown that scleral lens treatment has decreased the indication for transplant in patients with severe keratoconus by more than half  and is why I believe a scleral lens is the treatment of choice for moderate to severe keratoconus.
- Scleral lenses. For improved visual acuity, gas permeable scleral lenses are usually the preferred treatment. Scleral lenses vault over the cornea, replacing its irregular shape with a smooth, uniform refracting surface that provides clarity and comfort. (more information below)
- Custom soft contact lenses. These customized soft lenses are specially designed to correct mild-to-moderate keratoconus.
- Piggyback contact lenses. For those with keratoconus, fitting a gas permeable (hard) contact lens over a cone-shaped cornea may at times prove uncomfortable. “Piggybacking” involves placing a soft contact lens over the eye and then placing a GP lens over the soft lens. This increases wearer comfort because the soft lens acts like a cushioning pad under the rigid GP lens.
- Hybrid contact lenses. These lenses combine a highly oxygen-permeable rigid center with a soft peripheral “skirt”. Some hybrid lenses are specifically designed for keratoconus, with the central GP area of the lens vaulting over the cone-shaped cornea.
- Intacs. This small curved device is surgically placed in your cornea to help flatten the corneal curvature and improve vision.
- Corneal collagen cross-linking. Used together, special UV light and eye drops can strengthen the cornea, thus flattening your cornea and preventing further expansion.
- Corneal transplant. As a last resort, you may be advised to undergo a corneal transplant, where all or part of your diseased cornea is replaced with healthy donor cornea tissue. Even after a transplant, however, you may still need to wear glasses or contact lenses for clear vision.
Contact Dr. David Yoo & Dr. Daniel Quon at Specialty Contact Lens Center at South Coast Optometry to find out whether scleral lenses are right for you.
Specialty Contact Lens Center at South Coast Optometry helps patients from Costa Mesa, Orange County, Newport Beach, and Irvine throughout , do all the things they enjoy — but with clearer vision.