Introduction
The cornea is the transparent dome-shaped portion of the eye that resembles a ball that surrounds the front region of the eye. It encloses the anterior chamber (fluid-filled cavity), iris (center opening), and pupil (colored part). The cornea is made up of cells and proteins. There is no blood vessel in the cornea as it clouds and prorects the eye from refracted light. The primary role of the cornea is to bend or refract the light that enters the eye leads to blurry vision. This helps determine how effectively the eye can focus on close-up and distant objects. The scars may affect eyesight if the cornea is injured due to disease, infection, or injury. These scars could block or distort the light entering the eye.
What Causes Corneal Curvature Problems?
The exact cause is unknown. However, research states that due to a lack of protective antioxidants in the cornea, the structure of the cornea lacks its stability and loses its round shape resulting in bulging it outward, causing corneal curvature. In addition, collagen, a tiny protein fiber in the eye, aids in holding the cornea in place. However, these fibers cannot maintain their form when they become weak. As a result, the cornea gradually resembles a cone. Other causes of corneal curvature include:
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Genetics - Studies show corneal curvature problems may run in families. There may be a hereditary component behind some people being born with corneas that do not curve properly, yet the cause remains unclear.
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Eye Inflammation - The tissue of the cornea can be damaged by inflammation brought on by conditions such as allergies, asthma, or eye infections.
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Aging - Age is one of the causative factors for problems associated with curvature of the cornea. Several specific conditions, such as keratoconus and astigmatism, significantly influence aging.
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Eye Trauma - Excessive rubbing of the eye can wear down the cornea and affect the concealed shape, and its curvature leads to the condition called keratoconus.
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Eye Disorders - Eye disorders such as down syndrome, osteogenesis imperfecta, retinitis pigmentosa, and myopia.
What Conditions Can Affect Corneal Curvature?
The eye problems that can affect corneal curvature include:
1. Keratoconus - It is a progressive eye disease that causes thinning of the cornea and distorts the cornea into a cone shape. The signs and symptoms of keratoconus include:
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Blurry vision.
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Issues with driving at night, including halos or streaks surrounding bright lights.
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Changes in glass prescriptions.
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Increased sensitivity to brightness and light.
2. Astigmatism - When a person has astigmatism, their cornea is not exactly round; instead, it frequently has an egg or football shape and curves differently from top to bottom than it does from side to side. Sometimes the light may focus on two locations on the retina rather than one, leading to double vision. The astigmatism are two types, which are
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Corneal astigmatism.
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Lenticular astigmatism.
3. Myopia - Myopia is one of the most common eye defects, also known as nearsightedness, in which nearby objects are visible clearly, but distant objects are blurry. This is because light rays from a distant object coming towards the eye are almost parallel to each other, and when these rays enter the eye, they converge in front of the retina. This is one of the reasons for the blurriness. The corneal curvature in myopia patients is more significant from the central to the outside in all directions. It can be corrected by using a concave lens. Because a concave lens diverges, the light rays fall on the lens at such an angle they refract and come together.
4. Marfan Syndrome - It is a connective tissue disorder that affects the ocular, cardiovascular, and skeletal systems. The shape of the cornea is flat. It is associated with conditions such as decreased corneal curvature, corneal astigmatism, early myopia, and retinal detachment.
How to Diagnose the Problems associated With Corneal curvature?
Various diagnostic methods can measure corneal curvature.
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Keratometry - Keratometer or ophthalmometer is an optical device used to measure the central corneal curvature; the procedure is known as keratometry. Keratometry is based on the principle that the anterior surface of the cornea acts as a convex mirror, and the size of the image formed varies with curvature.
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Intraocular Lens (IOL) Master - Intraocular lens master is a biometry measurement test that helps to measure the corneal curvature, eyeball size, and anterior chamber depth of the eye.
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Computerized Corneal Mapping - Some specialized photographic eye tests like corneal tomography and corneal topography help record the detailed shapes and thickness of the cornea.
What Are the Treatment Options Available for Corneal Curvature Problems?
The various treatment options available for corneal curvature problems include the following:
1. Eyeglasses or Contact Lenses - For mild cases, the doctors may recommend glasses or contact lenses that can help to correct blurry vision or irregularly shaped cornea.
2. Laser Treatment - It is a procedure performed with a laser to reshape the corneal structure to improve vision. The surgeon cuts a tiny flap in the cornea during this surgery using a keratome tool or femtosecond laser. After lifting the flap, they utilize a laser to reshape the cornea beneath it. The surgeon then repositions the flap where it will heal.
3. Cornea Transplant or Keratoplasty - A cornea transplant involves removing the patient's damaged cornea and replacing it with a healthy cornea during surgery to restore vision. The various types of keratoplasty include:
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Penetrating Keratoplasty - Penetrating keratoplasty is a corneal operation where the donor and recipient cornea can be removed in a circular shape using a surgical cutting device named trephine.
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Endothelial Keratoplasty - Endothelial keratoplasty is a surgical corneal operation where the diseased part can be removed from the back part of the corneal layer.
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Artificial Keratoplasty - Individuals might be given an artificial cornea if they do not qualify for a donor cornea transplant. Keratoprosthesis is the name of this procedure.
4. Corneal Collagen Cross-Linking - In this technique, the doctor may apply drops of riboflavin (vitamin B12) and ultraviolet light on the cornea to strengthen the cornea's collagen fibers.
Conclusion
Corneal curvature resembles a steep localized curvature in the cornea that resembles a cone. Irregularity of corneal curvature causes eye defects such as keratoconus, myopia, and astigmatism. Therefore, it is advised to consult an ophthalmologist and have a comprehensive routine eye check-up, maintain a healthy diet, keep the blood sugar levels in check, and rest the eyes.
