Most people disregard a lack of sharpness of vision as a symptom of old age or needing a new prescription for their eyeglasses. And while this may be the case for some, blurred vision is also a symptom of keratoconus, a progressive eye disease that can degrade your vision over time.
If you’re unsure if you might have keratoconus, read on. The leading ophthalmology clinic in Dubai highlights everything you need to know about this progressive degenerative disorder — from causes and symptoms to keratoconus treatments.
What is keratoconus?
Keratoconus is a progressive eye disorder that causes the cornea, the clear dome-shaped surface of your eye, to thin out and protrude like a cone. As a healthy cornea is responsible for focusing light, providing clear vision, keratoconus distorts the shape of the cornea, leading to a decrease in visual acuity.
Keratoconus commonly affects both eyes, though one eye may be more severely affected than the other. This eye disorder typically presents itself during puberty and continues to deteriorate visual acuity for approximately 10 to 20 years before slowing or stopping altogether.
Causes and symptoms of keratoconus
Certain genetic and environmental factors have been found to increase the risk of developing keratoconus. Evidence shows that one in ten people who suffer from keratoconus have a parent who also suffers from the disorder. Males also present higher tendencies for the disorder.
Overexposure to ultraviolet rays is also an associating factor to an individual developing keratoconus.
Other contributing factors as to whether or not one may develop keratoconus include chronic eye inflammation and excessive eye rubbing, since both can contribute to the destruction of the corneal tissue.
Several conditions and disorders such as Down syndrome, ocular allergy, Marfan syndrome, and Ehlers–Danlos are also known to cause keratoconus.
Signs of keratoconus
Symptoms of keratoconus vary depending on how advanced the disorder is. In the early stages, individuals may report symptoms that include blurry vision, sensitivity to glare and light, eye redness, and swelling of the eyes.
In its more advanced stages, cloudy vision, poor night vision, sudden worsening of visual acuity, and frequent changes to eyeglass prescriptions are common symptoms. In rare cases, scarring of the cornea can occur, leading to even more significant vision loss.
To diagnose whether someone has keratoconus, an eye doctor may perform several different tests. Typically, these are done during a routine eye exam.
The most common test done is computerized corneal topography.
Topography measures the curvature of the cornea. As keratoconus distinctly changes the shape of the cornea, so this test can help establish what condition the cornea is in, assisting doctors in making the appropriate diagnosis.
Other diagnostic procedures used to determine if an individual may have keratoconus include examining the patient’s family eye history, history of allergies, ultrasound pachymetry, and a hard or gas permeable contact lens trial.
These tests help eliminate other causes of blurry vision, thereby helping confirm the presence of keratoconus.
Keratoconus treatment options
There are several treatment options available to individuals suffering from keratoconus. The best keratoconus treatment is determined by what stage the disorder is at.
Eyeglasses or contact lenses
In early keratoconic cases, eyeglasses may be prescribed to address refractive errors caused by this disorder. As vision irregularities progress in keratoconic patients, special contact lenses like scleral contacts and other contact designs are prescribed to treat visual deterioration.
Scleral contact lenses differ from regular traditional soft contacts used to treat refractive errors (nearsightedness, farsightedness, astigmatism) in that these are larger in diameter, vaulting over the distorted cornea and resting on the sclera, the white part of the eye.
The unique design of scleral contacts addresses the issue of discomfort and helps the wearer achieve the desired vision correction.
An eye doctor may also prescribe other types of contacts like rigid, gas permeable contact lenses, piggyback lenses (hard contact lenses that sit atop soft ones), and hybrid lenses (rigid center, soft outer ring contacts).
Keratoconic patients will need to get regular eye exams to confirm that the contacts continue to fit correctly, as ill-fitting contacts can cause further complications to the cornea.
Corneal cross-linking is a non-invasive therapeutic procedure performed to slow the progression of keratoconus. The use of corneal cross-linking in the early stages of the disorder can help prevent further deterioration and strengthen the cornea.
Other benefits of corneal cross-linking include the reduction of refractive errors associated with keratoconus, enhances contact lens wear, maintains the current level of vision, and reduces the need for corneal transplant surgery.
Corneal cross-linking uses riboflavin (vitamin B2) eye drops and a specific type of UV light to develop new corneal collagen cross-links. Because keratoconic patients don’t have enough corneal collagen fiber cross-links, this procedure helps develop thicker and stronger corneal collagen.
Think of these new cross-links as structural support for your cornea. They strengthen and stabilize the cornea, preventing any further corneal distortion.
If an individual has an advanced case of keratoconus, surgery may be required. Surgical procedures are only performed if satisfactory vision cannot be achieved by any of the other prescribed treatment options (contact lenses or corneal cross-linking).
Two primary surgeries may be performed on keratoconic patients with severe cases.
The first surgical option is the insertion of corneal inserts or implants into the eye. Also known as Intacs, this procedure inserts implantable ring segments into the cornea. When inserted, the ring segments reshape the cornea, partially correcting it closer to its original dome shape.
As the ring inserts are made from a biocompatible material, there is little to no adverse effects as a result of the surgery. This surgical option is performed as an outpatient procedure and typically lasts for about 15 minutes.
The second surgical option is cornea transplant – either partial thickness, or full thickness / penetrating keratoplasty. As the name implies, the surgeon surgically removes the keratoconic patient’s corneal tissue, and replaces it with donor tissue with no corneal irregularities.
This procedure is typically reserved for only the most severe of keratoconic cases. Less than 20 percent of keratoconic patients will ever require a corneal transplant. While corneal transplant surgery has been performed for many decades and generally successful, complications can still arise.
Potential complications include graft rejection, infection, and keratoconus reoccurring in the corneal transplant. Partial thickness grafts reduces the rejection rate considerably, and the use of lasers to shape the tissue, has made better precision – and thus postop vision – possible
Regardless of what treatment option a keratoconic individual may need, their eye doctor will assess the severity of their condition and walk them through their available options, recommending the best course of action for treatment.
While there is no cure for keratoconus, individuals who are diagnosed early and receive the correct treatment procedure can successfully manage this disorder, with less severe vision disruption risk.
If you feel you or a loved one may be experiencing symptoms of keratoconus, speak to your eye doctor today.
Dr. Millicent M. Grim, Specialist Ophthalmologist & LASIK Specialist, is the Medical Director of Gulf Eye Center in Dubai. Since 2002, Gulf Eye Center’s highly qualified ophthalmologists and optometrists/ODs have been successfully treating a wide range of eye conditions using advanced techniques. They also provide comprehensive eye care and vision restoration procedures for people of all ages.