Keratoconus
Understanding Keratoconus
In a healthy eye, your cornea maintains a smooth, dome-like curve that helps focus incoming light. When keratoconus develops, the structural proteins in your cornea weaken and can no longer hold this regular shape. Over months or years, the cornea becomes thinner in certain areas and starts to bulge forward irregularly.
This cone-shaped distortion scatters light rays instead of directing them to a single point on your retina. The result is vision that becomes increasingly blurred, doubled, or streaked, especially at night.
Many people first notice that their eyeglass prescription changes frequently, sometimes every few months. You might find that new glasses provide clear vision for only a short time before your vision becomes blurry again. Other early signs include increased sensitivity to bright lights and glare, which can make night driving uncomfortable.
- Frequent changes in your eyeglass or contact lens prescription
- Blurred or distorted vision that glasses do not fully correct
- Increased glare and halos around lights
- Eye strain or discomfort during reading or screen time
As keratoconus progresses, you may see multiple ghost images of a single object, a condition called monocular diplopia. Straight lines might appear wavy or bent, and you may struggle to see fine details even with corrective lenses. Some people notice that one eye becomes significantly more affected than the other.
Additional signs of progression include increasing irregular astigmatism that becomes harder to correct, reduced best-corrected vision even with optimal lenses, increasing difficulty tolerating contact lenses, and in advanced cases, visible corneal scarring. Vision changes can happen slowly over many years or progress more rapidly during your teens and twenties, though the timeline and severity vary considerably from person to person.
Although keratoconus typically progresses gradually, sudden changes require urgent attention. Acute corneal hydrops occurs when fluid breaks through the back layer of your cornea and can cause rapid changes in vision and discomfort. Contact our office immediately if you experience any of these warning signs.
- Sudden marked blurring or foggy vision in one eye
- New significant sensitivity to light and tearing
- Increasing redness or severe eye pain
- If you wear contact lenses, any discharge or a white or gray spot on your cornea
- Vision changes so rapid you cannot perform daily tasks safely
If you wear contact lenses and develop any of these symptoms, remove your lenses immediately and seek same-day evaluation. After hours, consider urgent care or emergency evaluation to rule out infection or other serious complications.
Who Is at Risk for Keratoconus
Keratoconus most commonly appears during the teenage years or early twenties, though it can develop in childhood or later in adulthood. If you have a parent or sibling with keratoconus, your risk increases significantly compared to the general population. Eye doctors often recommend screening family members of affected patients, especially during adolescence when the condition typically emerges.
The condition affects people of all ethnic backgrounds, though research suggests slightly higher rates in certain populations. Both males and females can develop keratoconus, with some studies showing a modest increase in males. Because keratoconus or subtle forms of corneal irregularity can be present without symptoms, thorough screening is important before elective refractive surgery such as LASIK, as these conditions are contraindications to the procedure.
Vigorous or chronic eye rubbing is strongly associated with keratoconus development and progression, and avoiding eye rubbing is essential for patients at risk or diagnosed with the condition. While the mechanical force from rubbing appears to damage delicate corneal tissue and accelerate weakening, keratoconus is multifactorial, involving genetic predisposition, environmental factors, and biomechanical changes. People with seasonal allergies, eczema, or asthma often rub their eyes more frequently due to itching and irritation.
- Chronic eye rubbing from allergies or habit
- Seasonal or year-round allergic conjunctivitis
- Atopic conditions like eczema or hay fever
- Vernal keratoconjunctivitis, a severe allergic eye condition
Certain genetic and connective tissue disorders carry an increased risk of keratoconus. Down syndrome shows a particularly strong association, with keratoconus occurring much more frequently in this population. Disorders that affect collagen and connective tissue throughout the body can also weaken corneal structure.
Eye doctors monitor patients with Ehlers-Danlos syndrome, Marfan syndrome, and osteogenesis imperfecta more closely for corneal changes. Floppy eyelid syndrome, which often overlaps with obstructive sleep apnea, has also been linked to keratoconus, possibly related to eye rubbing during sleep or eyelid trauma. In some patients, hormonal changes during pregnancy may be associated with disease progression, though this relationship is not fully understood and does not affect all patients.
How We Diagnose Keratoconus
During your exam, we begin by testing your vision with different lenses and evaluating how well glasses or contacts correct your sight. We carefully examine the front surface of your eye using a specialized microscope called a slit lamp, which allows us to see subtle changes in corneal shape and clarity. Experienced eye doctors can often identify characteristic clinical signs such as an irregular light reflex on retinoscopy, a Fleischer ring of iron deposits at the base of the cone, or fine stress lines in the cornea called Vogt striae.
We also assess your overall eye health, check your eye pressure, and examine your retina to rule out other conditions that might affect your vision.
Corneal topography creates a detailed color-coded map of your corneal surface, similar to a topographic map showing hills and valleys. This technology reveals even subtle irregularities in corneal curvature that indicate early keratoconus. We use these maps to track any changes over time and determine whether the condition is progressing.
Advanced imaging systems called tomographers go a step further by scanning both the front and back surfaces of your cornea. These devices measure elevation, curvature, and thickness at thousands of points, providing a complete three-dimensional picture of your corneal structure. Changes on the back corneal surface and in the distribution of the corneal layers can be important clues in detecting early disease.
Pachymetry is a quick test that measures the thickness of your cornea at its center and multiple other locations. In keratoconus, corneal thickness typically shows areas of significant thinning compared to normal values. The thinnest point often corresponds to the area of maximum bulging.
- Ultrasound pachymetry uses sound waves for precise thickness readings
- Optical pachymetry captures measurements during corneal imaging
- Serial measurements help us monitor whether thinning is progressing
- Thickness patterns combined with shape data confirm the diagnosis
Most diagnostic tests for keratoconus are noninvasive and well tolerated. You simply rest your chin on a support while looking at a target, and the instruments scan your cornea using light or sound waves. Ultrasound pachymetry involves a probe gently touching the corneal surface after numbing drops are applied, which is typically comfortable but briefly involves contact. Most tests take only a few seconds to a few minutes to complete, and you can return to your normal activities immediately afterward.
If you wear contact lenses, we may ask you to stop wearing them for a period before your testing appointment. Soft lenses can usually be discontinued a few days beforehand, while rigid or scleral lenses may require a longer break to allow your cornea to return to its natural shape. We will provide specific instructions based on your lens type. We may perform additional testing to establish a baseline and create a complete profile of your corneal health. These records become invaluable for comparing future exams and catching any progression early.
Treatment Options for Keratoconus
Treatment for keratoconus addresses two distinct goals. Glasses and contact lenses improve your vision by compensating for the irregular corneal shape, but they do not alter the underlying condition. Corneal collagen cross-linking is the primary treatment designed to strengthen the cornea and slow or stop disease progression in appropriate candidates. Your treatment plan may combine vision correction with procedures to stabilize your cornea.
When keratoconus is very mild, regular eyeglasses or soft contact lenses may provide adequate vision correction. This approach works best when corneal distortion is minimal and your prescription is relatively stable. However, as the condition progresses, glasses alone usually cannot correct the irregular astigmatism that keratoconus creates.
We monitor your vision closely during this stage, and if you notice declining clarity or more frequent prescription changes, we may recommend transitioning to specialty contact lenses designed for irregular corneas.
Rigid gas permeable lenses, often called RGP or hard lenses, vault over the irregular corneal surface and create a smooth optical interface with your tear film. This design often restores vision far better than glasses can for moderate keratoconus. While these lenses require an adaptation period, most patients adjust within a few weeks.
- Custom-designed lenses fitted specifically to your corneal shape
- Hybrid lenses that combine a rigid center with a soft outer skirt for comfort
- Piggyback systems using a soft lens beneath a rigid lens
- Regular follow-up appointments to refine the fit as your cornea changes
Scleral lenses are larger specialty lenses that rest on the white part of your eye rather than your cornea. They create a fluid-filled space over your cornea, providing exceptional comfort and vision even with advanced keratoconus. Many patients who could not tolerate traditional rigid lenses find scleral lenses much more comfortable for all-day wear.
We customize each scleral lens based on detailed measurements of your eye, and the fitting process may require several visits to achieve the optimal design. These lenses have become a preferred option for many patients because they improve vision and comfort, though they do not treat the underlying corneal changes or prevent progression.
Corneal collagen cross-linking is a procedure that strengthens the structural bonds within your cornea and is intended to slow or halt keratoconus progression. We apply riboflavin eye drops to your cornea and then activate them with controlled ultraviolet light. This treatment creates new links between collagen fibers, making your cornea more rigid and resistant to further bulging.
The most common approach, epithelium-off cross-linking, involves gently removing the surface layer of corneal cells before applying the riboflavin. A bandage contact lens is placed at the end of the procedure to aid healing. Recovery typically involves several days of grittiness or discomfort, light sensitivity, and blurred vision, with vision gradually improving over the following weeks to months. We provide a regimen of antibiotic and anti-inflammatory eye drops and guidance on activity and water exposure restrictions during healing.
Cross-linking is typically recommended for patients showing documented progression or those at high risk, especially younger individuals whose keratoconus may be more active. Studies show that cross-linking can stabilize the cornea in many patients, though results vary and some patients may experience continued progression or require repeat treatment.
- Infection is rare but serious and requires prompt treatment
- Temporary corneal haze or scarring can occur and may affect vision
- Delayed healing or prolonged discomfort may happen in some patients
- Most patients still need glasses or contact lenses after the procedure
- Cross-linking may not be appropriate if the cornea is too thin or has certain scarring patterns
Intacs are small, curved plastic segments that we insert into the cornea to help flatten the cone and improve its shape. These implants can reduce irregular astigmatism and may improve vision or make contact lens fitting easier. The procedure is typically performed in an operating room, and the rings can be removed or replaced if needed.
Intacs are generally reserved for select cases and are often used in combination with cross-linking to both reshape and strengthen the cornea. Utilization of corneal ring implants varies among eye care practices based on individual patient factors and surgical expertise.
- Visual results vary and often improve contact lens fitting more than eliminating the need for lenses
- Possible side effects include glare, halos, or difficulty with night vision
- Infection, inflammation, or ring migration requiring removal can occur
- Typically not used when significant scarring is present or corneas are very thin
When keratoconus is very advanced and other treatments cannot provide adequate vision, a corneal transplant may be necessary. During this surgery, we replace the damaged central portion of your cornea with healthy donor tissue. Partial-thickness procedures that preserve your own healthy corneal layers are used in many cases, though full-thickness penetrating keratoplasty remains necessary when significant scarring, prior hydrops, or other factors are present.
Deep anterior lamellar keratoplasty removes only the front layers of the cornea, leaving your own endothelial cells intact. This approach can reduce the risk of rejection and often provides excellent long-term outcomes. Recovery takes time, with sutures often remaining in place for many months and astigmatism managed over the course of a year or more. Many patients still need glasses or rigid or scleral contact lenses after transplant to achieve their best vision.
After a corneal transplant, it is critical to watch for signs of rejection or infection and seek urgent evaluation if they occur.
- Sudden redness or increasing pain
- Significant light sensitivity
- Rapid drop in vision
- Discharge from the eye
Living Well with Keratoconus
Avoiding eye rubbing is the single most important habit you can develop to slow keratoconus progression. Even when your eyes feel itchy or irritated, resist the urge to rub them. Instead, use preservative-free artificial tears to soothe discomfort and rinse away allergens or irritants.
- Keep your hands away from your eyes throughout the day
- Use cool compresses for itching instead of rubbing
- Wear wraparound sunglasses outdoors to reduce glare and UV exposure
- Maintain good control of allergies to minimize itching triggers
- Consider protective eyewear during sports or activities with eye injury risk
If allergies trigger your eye rubbing, we may recommend prescription or over-the-counter allergy eye drops to control itching and inflammation. Antihistamine medications taken by mouth can also help reduce overall allergic responses. Identifying and avoiding your specific allergy triggers, such as pollen, dust mites, or pet dander, makes a significant difference.
During high allergy seasons, keep windows closed, use air conditioning with clean filters, and shower before bed to remove pollen from your hair and skin. These strategies reduce nighttime eye rubbing that you might not even be aware of. Avoid chronic unsupervised use of decongestant eye drops that promise to get the red out, as these can cause rebound redness with prolonged use. Steroid eye drops should only be used under close eye doctor supervision due to potential side effects including increased eye pressure and cataract development.
Specialty contact lenses require careful handling and consistent hygiene practices. Your eye care team will teach you the proper insertion, removal, and cleaning techniques specific to your lens type. Building up your wearing time gradually helps your eyes adjust, especially with rigid lenses. Start with a few hours each day and increase the duration as comfort improves.
Strict hygiene and safe lens-wearing habits are essential to protect your eyes from serious infections.
- Always wash your hands thoroughly before touching your lenses
- Do not sleep in your lenses unless explicitly prescribed for extended wear
- Keep lenses and cases away from all tap water; do not rinse, shower, or swim while wearing lenses unless specifically advised
- Replace your lens case regularly as directed
- Stop wearing your lenses immediately and contact our office if you develop pain, significant redness, discharge, or light sensitivity
We typically schedule follow-up appointments every six to twelve months, or more frequently if your keratoconus is progressing. These visits allow us to repeat corneal imaging tests and compare the results to your previous scans. Catching progression early gives us the opportunity to intervene with treatments like cross-linking before significant vision loss occurs.
Keep all scheduled appointments even if your vision seems stable, as subtle changes might not be noticeable to you in daily life. Bring your current glasses and contact lenses to each visit so we can assess how well they are still working for you.
Frequently Asked Questions
Keratoconus very rarely leads to complete blindness, and with modern treatment options, severe vision loss is uncommon. Most patients maintain functional vision through specialty contact lenses or, when necessary, corneal transplant surgery. However, without appropriate treatment or in the presence of complications such as severe scarring, hydrops, or infection, significant permanent vision loss is possible. Early detection and appropriate treatment greatly improve the long-term outlook and underscore the importance of regular follow-up care.
Coverage for specialty lenses varies widely among insurance plans, but many policies provide at least partial coverage for medically necessary lenses when keratoconus is documented. Some plans cover scleral or rigid lenses under medical benefits rather than routine vision benefits. Our staff can help you verify your specific coverage and explore options if your plan does not include specialty lens benefits.
Estimates suggest that approximately 10 to 20 percent of keratoconus patients may eventually need a transplant, though this figure varies by era, access to earlier interventions such as cross-linking, and patient population studied. With current management strategies including corneal cross-linking and advanced specialty contact lenses, transplant rates have decreased compared to previous decades. Patients who maintain regular care and avoid eye rubbing have the best chance of preserving their corneas long-term.
Keratoconus does have a genetic component, and it tends to run in families more often than would occur by chance alone. However, the inheritance pattern is complex, and not everyone with a family history will develop the condition. Researchers have identified several genes associated with increased risk, but environmental factors like eye rubbing also play an important role in whether the condition develops and progresses.
Many people with keratoconus continue to drive safely, especially when their vision is well-corrected with specialty contact lenses or glasses. Your ability to drive depends on meeting your state's visual acuity requirements and your comfort level with glare and night vision. We can perform specific testing to determine if your corrected vision meets legal driving standards and discuss any restrictions that might apply to your situation.
Getting Help for Keratoconus
If you notice frequent changes in your vision, increased blurriness that glasses do not fix, or any of the warning signs we have discussed, we encourage you to schedule a comprehensive eye examination. Our eye doctors have the advanced diagnostic equipment and expertise needed to detect keratoconus early and create a personalized treatment plan that protects your vision and helps you maintain your quality of life. This information is intended for general education and is not a substitute for an in-person examination and individualized medical advice. If you experience urgent symptoms, seek prompt evaluation.