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Keratoconus (KC) is a progressive, non-inflammatory degenerative corneal disease that can affect one or both eyes. It is hereditary in nature, typically affecting young people in the prime of their active years. It has an incidence rate of one in 500.
The cornea is a mass of transparent tissue that forms the front of the eye; through it we can see the iris and the pupil.
Keratoconus can lead to impaired vision and even serious damage if the disease is allowed to progress to a stage of dilation and thinning of the cornea which loses its normal spherical shape becomes cone-shaped.
Causes of keratoconus
To date, the causes of keratoconus are still unknown. Several researchers admit a genetic predisposition because it is observed that about 15% of those affected by keratoconus have at least one member of the family with the same disease.
Some studies have focused on the imbalance of enzyme activity within the cornea, which would be more vulnerable to oxidative damage exerted by free radicals. This vulnerability would lead to a weakness in the corneal tissue resulting in thinning and reduced biomechanical resistance.
Also, microtraumas caused by contact lenses and eye rubbing are indicated among the contributing factors.
When does keratoconus develop?
Keratoconus occurs in adolescence at around 14 years of age, although the onset in childhood is not uncommon. Usually, it initially affects only one eye and after a few years it spreads to the other. Forms of keratoconus that affect only one eye are very rare. The evolution is quite variable and unpredictable, it can spontaneously slow down, but it never stops entirely. Unfortunately, it is not considered a rare disease as we have one new case per 500 persons per year when considering topographic forms of the disease, with a slight preponderance of male subjects.
Keratoconus and pregnancy
This case report was published in the journal “Cornea” on June 24, 2011.
It is well known that pregnancy produces changes in hormone levels. Sometimes these hormonal changes can affect the eyes and also patients with keratoconus.
Turkish eye specialists have identified four cases of pregnant women with keratoconus who showed signs of change in visual acuity and corneal curvature.
These women had no other diseases or risk factors for keratoconus so the researchers concluded that “the hormonal changes during the pregnancy period may adversely affect corneal biomechanics and pregnancy could be a previously unrecognized risk factor for the progression of keratoconus. To the best of our knowledge, at present this is the first study that shows a progression of keratoconus induced by pregnancy in patients in the absence of other correlated disease.”