The cornea is normally a clear and round-shaped outer layer that serves as a window of any eye. It lets the light enter and focus on the light-sensitive retina. Eventually, it forms an image for the brain. If ever this round-shaped cornea changes to a conical shape, then the image produced on the retina would be unclear and blurry. Such kind of situation arises when the corneal layer thins, weakens and bulges into a conical shape. It is a kind of an ocular disease to which the medical scientists have named Keratoconus. Keratoconus is a blend of two Greek words, ‘kerato’ and ‘konos’. ‘kerato’ means cornea and ‘konos’ means cone.
Keratoconus can occur in one or both eyes. It usually affects one eye and, over time, it can prevail on the other eye. The sufferers from Keratoconus are teenagers or young adults. Keratoconus occurs in one out of every 2000 people.
The medical scientists cannot precisely track down the underlying cause of Keratoconus. Most of the cases recorded about its occurrence are due to random unknown reasons. Some of the causes are listed below:
- Eye Rubbing
- Genetic factors
- Environmental factors
- Non-inflammatory disorder
- Certain underlying disorders
- Weak collagen fibres
One of the apparent reasons which result in Keratoconus in the younger age is the rubbing of an eye forcibly, which severely affects the corneal layer.
Most of the researchers opine that genetic reason is one of the multiple and complex factors that pave the way for Keratoconus. The family history of Keratoconus supports this opinion in some cases. The genetic predisposition leads to develop the disorder. A genetically predisposed person is a bearer of a gene (or genes) for the disorder, but the certain circumstances trigger the disorder condition to develop Keratoconus. The researchers still strive to identify these specific genes.
Therefore, the doctors advise that if you suffer from Keratoconus and you also have children, then you must get their eyes checked for Keratoconus starting at age 10. Certain allergic conditions may develop it more rapidly in people. The chronic eye rubbing could be one of them.
The researchers believe that some Environmental risk factors may facilitate the development of Keratoconus. These factors include atopy, which involves hypersensitivity reactions such as hay fever (allergic rhinitis), eczema (atopic dermatitis), sleep apnea, or allergic asthma. Nevertheless, the research findings have revealed an association with the development of Keratoconus and any of these risk factors.
Keratoconus is commonly viewed as a non-inflammatory disorder. Inflammation is a protective reaction of tissues to injury or infection or irritation. Although Keratoconus has been assumed as a non-inflammatory disorder, the recent evidence has revealed that that includes abnormally high levels of proteolytic enzymes. It has an association with free radicals and oxidative stress, or the presence of cytokines, specialized proteins secreted from certain immune system cells that stimulate the function of other immune system cells. However, the determining of the complex, underlying causes of Keratoconus requires further researches.
Certain underlying disorders
Certain underlying disorders lead to the development of Keratoconus. Down syndrome, sleep apnea, asthma, Leber congenital amaurosis, and various connective tissue disorders including Ehlers-Danlos syndrome, Marfan syndrome, or brittle cornea syndrome, are indirectly counted as such underlying disorders.
Weak collagen fibres
Collagens are tiny fibres of protein in the eye. Collagens sustain the cornea in place and prevent it from bulging. The weak collagen fibres cannot hold the shape of the cornea, which grows progressively in more conelike shape.
A decrease in protective antioxidants in the cornea causes Keratoconus. The antioxidants protect the collagen fibres from the damaging by-products made by corneal cells. If antioxidant levels decrease, the collagen weakens to result in Keratoconus.
Keratoconus is an eye disease in which the round shape of cornea changes to the conelike shape. Consequently, it produces the blurry and unclear images in the brain through the eyes. The patients of Keratoconus are of age 10 – 30 years. Although the researchers have not yet reached the exact mechanism that causes Keratoconus, they have identified some of the factors that help develop this disease in the people. The eye rubbing, improperly fitted contact lens, genetic and environmental factors, weak collagen fibres of the cornea, a decrease in antioxidants, atopy are the prominent reasons for the progress of Keratoconus.