Keratoconus is a chronic, lifelong eye disorder characterized by the cornea’s thinning and bulging, leading to distorted vision. So, learning about this eye condition is crucial for early detection, effective management, and optimal eye health.
This blog will provide extensive knowledge about keratoconus, highlighting some common symptoms, significant causes, and a list of effective treatments available to manage this condition effectively.
What Is Keratoconus?
Keratoconus is a progressive eye disorder that affects the shape of the cornea, causing it to become thin and bulge into a cone-like shape. This condition can lead to visual distortions, decreased visual acuity, and increased sensitivity to light. Understanding the causes, symptoms, and available treatment options for keratoconus is essential for early detection and effective management.
Generally, keratoconus occurs in teenagers but can also manifest during childhood. Moreover, if left untreated in children or teenagers, the keratoconus continues to progress. That’s why early diagnosis of keratoconus is required.
What Causes Keratoconus?
Several factors have been identified as potential contributors, including genetic predisposition, collagen abnormalities, chronic eye rubbing, and certain environmental and hormonal influences. Research suggests that a combination of genetic and environmental factors likely play a role in the development of keratoconus. However, the exact cause of keratoconus remains elusive.
- Genetics – This plays a significant role as there is a higher likelihood of developing keratoconus if someone in the family has the condition. Researchers have identified specific genes that may be associated with its occurrence.
- Eye Rubbing – Intense eye rubbing, mainly when done vigorously and frequently, have been linked to keratoconus. This is because the constant friction weakens the cornea over time, leading to its abnormal shape.
- Chronic eye irritation – Such as allergies or poorly fitted contact lenses may also contribute to the condition.
- Exposure to Ultraviolet (UV) rays – Excessive exposure to UV rays from the sun without protective eyewear has been suggested as a potential risk factor.
While the exact interplay between genetics and environmental factors is not yet fully understood, recognizing these potential causes can aid in preventive measures and the pursuit of appropriate treatment options.
What Makes Keratoconus Worse?
If performed on the affected eye, laser vision correction surgeries like LASIK can pose risks and potentially worsen keratoconus. Thus, it is suggested to not undergo any surgery if any individual is suffering even a minor degree of keratoconus unless specifically recommended by an eye doctor.
Furthermore, it is recommended to seek an ophthalmologist’s guidance to determine the appropriate course of action for individuals with keratoconus considering laser vision correction surgery.
Improperly fitted contact lenses, excessive exposure to ultraviolet (UV) radiation, and poor eye care practices can also worsen keratoconus.
What are the risk factors for keratoconus?
Here are the factors responsible for developing this eye disorder:-
Keratoconus can run in families, which means you can inherit this disorder from your parents or grandparents. Normally, congenital abnormalities and mutations are detected in people having keratoconus. But not all cases of keratoconus are caused due to genetic complications.
Collagen provides strength and stability to the cornea, and when these fibers are compromised, it can contribute to the development and progression of keratoconus. Therefore, collagen abnormalities in the cornea are recognized as one of the underlying factors associated with the risk of keratoconus.
Doctors and researchers also suggested that an imbalance of certain enzymes within the cornea may play a role in developing keratoconus. Enzymes, like matrix metalloproteinases (MMPs), are responsible for maintaining the integrity of the cornea. Excessive functions of MMPs or a lack of enzymes that inhibit their activity can lead to corneal weakening and distortion.
Frequent eye rubbing has been linked to some individuals’ keratoconus progression. The repetitive rubbing stresses on the corneal surface cause thinning & distortion of the cornea.
What are the symptoms of keratoconus?
Keratoconus is a progressive eye concern with several symptoms. And awareness of these symptoms is essential for early diagnosis to manage this condition with proper treatment.
- Visual Distortion:
The primary symptom of keratoconus is distorted or blurred vision. The curvature is altered as the cornea (the part of the eye responsible for aiding vision by focusing on the light) becomes thin and changes its structure into a crooked cone-like shape, leading to irregular astigmatism (a condition wherein the irregular cornea shape blurs the vision focus). This can result in distorted vision, making it challenging to see minute details or read small letters.
- Increased Sensitivity to Light and Glare:
People suffering from keratoconus may find it challenging to tolerate bright sunlight, headlights of oncoming vehicles, or glare from computer screens or indoor lighting. This sensitivity can cause discomfort and make it harder to see clearly in certain lighting conditions.
- Frequent Changes in Eyeglass or Contact Lens Prescriptions:
As keratoconus is progressive, the corneal shape changes over time. This results in changes in the glasses or contact lenses of individuals with keratoconus to maintain optimal vision.
Note – Standard or soft contact lenses may no longer provide adequate vision correction, necessitating specialized lenses designed for irregular corneas, such as rigid gas permeable (RGP) contact lenses, sclera lenses or rose k lenses.
- Poor Night Vision:
The irregular shape of the cornea in keratoconus causes light to scatter as it enters the eye. This can make it difficult to see clearly in low-light conditions, such as at night or in dimly lit environments. Thus, people with keratoconus experience difficulties with night vision as they may notice halos or glare around lights, reduced contrast sensitivity, or impaired vision in low-light conditions.
- Eye Irritation and Redness:
Allergies are commonly seen in a keratoconic eye. Keratoconus can cause irritation, redness, and excessive tearing. The corneal changes and irregularities can lead to chronic eye irritation, foreign body sensation, and occasional eye rubbing. This discomfort may worsen throughout the day or in response to environmental factors, such as dry or windy conditions.
How is keratoconus diagnosed?
Here are some common diagnostics methods and tests:-
Test #1) Visual Acuity Testing:
The initial step of diagnosing keratoconus includes measuring visual acuity. This process involves an essential reading of the eye chart and examining letters or numbers from an advised distance. The results help determine the clarity and sharpness of your vision.
Test #2) Refraction Test:
This test determines refractive errors and evaluates the extent of vision correction needed. During this test, you can look through a series of lenses while reading an eye chart to determine the best prescription for your visual acuity. Retinoscopy May be performed which will show a scissoring reflex.
Test #3) Corneal Topography:
Corneal topography is a non-invasive imaging method that provides a detailed map of the cornea’s shape and curvature. This test measures the elevation and contours of the corneal surface, helping to identify irregularities associated with keratoconus. It can also aid in determining the severity and progression of the condition.
Test #4) Slit-Lamp Examination:
A slit-lamp examination allows the eye doctor to thoroughly analyze the cornea, iris, and other eye structures. By making use of a specialized microscope with a thin, intense beam of light, the doctor assesses the corneal surface for signs of cornea thinning, scarring, or other abnormalities associated with keratoconus.
Test #5) Keratometry:
Keratometry is a test to determine irregularities in astigmatism, a common characteristic of keratoconus; it measures the cornea’s curvature. This process is done with the help of a keratometer or auto keratometer to calculate the corneal curvature in different meridians.
Test #5) Pachymetry:
Pachymetry is a test to determine whether the cornea is thinner than usual, as thinning is a characteristic of keratoconus. This test is typically performed using an ultrasound device or an optical coherence tomography (OCT) machine.
How Is Keratoconus Treated?
Let’s discuss how it can be treated in different stages:-
Early Stages include keratoconus treatment without surgery
During the initial phases of keratoconus, contact lenses can address nearsightedness and astigmatism, effectively improving vision by accommodating the cornea’s irregular shape. As keratoconus develops and deteriorates, glasses become insufficient for clear vision, necessitating hard contact lenses.
It is crucial to have regular check-ups with an eye care specialist to monitor the condition’s advancement.
A treatment option for keratoconus is corneal collagen cross-linking, which involves the application of a Riboflavin solution to the eye. This solution is activated by ultraviolet (UV) light for a short duration. As a result, the solution promotes the formation of new collagen bonds, which aids in the recovery and preservation of the cornea’s strength and shape.
While collagen cross-linking cannot completely restore the cornea to its normal state, it can prevent further eye deterioration and potentially enhance vision. This procedure involves the removal of the thin outer layer of the cornea, known as the epithelium, to facilitate the penetration of riboflavin (also known as vitamin B2) into the corneal tissue.
The FDA (Food and Drug Administration) approved cross-linking as a treatment for keratoconus in April 2016 following successful clinical trials. These trials demonstrated that the procedure effectively stopped or sometimes even slightly reduced the bulging of the cornea within three to 12 months after treatment.
A donated cornea is replaced with the patient’s damaged cornea during a corneal transplant. After the transplant, vision may remain blurry for three to six months.
To prevent transplant rejection, medication needs to be taken as prescribed by the doctors. In most instances, glasses or contact lenses are still required after the surgery to achieve the clearest vision possible.
With advanced keratoconus, wearing a regular contact lens can become uncomfortable. To address this, Intacs, which are plastic, C-shaped rings, can be inserted to flatten the cornea’s surface and enhance vision. Additionally, intrastromal corneal ring segments (Intacs) may facilitate a more comfortable fit option for contact lenses.
Rigid Gas Permeable (RGP) Contact Lenses:
RGP lenses act as a new outer surface layer for the cornea, providing better visual acuity by neutralising the cornea’s irregular shape. As the concern increases, glasses and contact lenses can’t provide enough vision stability, so in that case, Rigid Gas Permeable contact lenses are recommended.
Hybrid Contact Lenses:
Hybrid lenses can be a good option for patients who find RGP Lenses uncomfortable. Hybrid contact lenses are a combination of soft and RPG lenses. They have a rigid center for correcting the corneal shape and a soft outer ring for increased comfort.
When Do You Need to See an Eye Specialist?
Seeking medical attention from an experienced eye care professional is crucial if you observe any indications or symptoms that could be related to eye conditions, such as keratoconus.
So, here are some specific circumstances that should prompt you to schedule an appointment with an eye specialist immediately:
- Changes in Vision
- Frequent Prescription Changes
- Distorted or Ghost Images
- Increased Eye Irritation
At Dr. Ritika Dalal’s clinic, we know the importance of accurate information in empowering you to make informed decisions. Our qualified surgeon is dedicated to providing the right solutions.