Corneal blindness is vision impairment resulting from the scarring, clouding or reduction in the transparency of the cornea. Cornea is the dome-shaped outermost clear layer of the eye.
The common causes of corneal blindness include:
- Congenital diseases
- Vitamin A deficiency
- Eye trauma
- Effects of viral, bacterial or fungal infection
- Application of traditional home remedies to relieve eye pain may result in eye damage
Prevalence of Corneal Blindness
The leading causes of blindness in the world are cataracts, macular degeneration due to aging, glaucoma and corneal blindness.
Corneal blindness accounts for a significant portion of all blindness cases. For instance, according to the World Health Organization, trachoma is responsible for an estimated 4.9 million blindness cases in the world.
Blindness is just one issue in the developing world and this article explains the need for increased spending to improve health.
Trachoma leads to corneal scratching and if left untreated thus causing corneal blindness. It results from an infection that affects both eyes. The infection leads to the inner areas of the eye lids scarring if treatment is not sought early. With time, the eyelashes turn inward and therefore rub against the cornea. Continuous irritation of the cornea leads to scarring which can eventually lead to vision loss.
Trachoma is less common in the West but is prevalent in most developing nations.
A characteristic of the cornea that makes it vulnerable to infection is the absence of blood vessels, meaning that there is no blood flowing through the cornea to help nourish it and help fight infection. The role of nourishing the cornea is left to the aqueous humor and tears.
Vitamin A Deficiency
Vitamin A is very important for vision. It always arises in cases of severe malnutrition.
Children growing up in areas hit hard with famine may not have access to food rich in vitamin A. The vitamin can be found in plenty in foods like carrots, fish, sweet potatoes, liver, tropical fruits, lettuce, dried apricots and dark leafy greens.
You need not worry about Vitamin A deficiency if you are living in the developed world and consume a balanced diet.
The prevalence of corneal blindness relative to other causes of blindness among younger people is very high. Those in poor rural communities are at a higher disadvantage.
Children in rural communities may be exposed to corneal blindness through injury or infection of the eye.
Communicable eye infections like onchocerciasis and trachoma can easily spread in a rural environment where there are no proper controls to guard against the spread of such infections. Also, when playing around in plantations or places with lots of shrubs, the eyes can be scratched by rough or contaminated leaves.
Fungal or bacterial infection of the cornea can also lead to vision loss. The infection can lead to reduction of visual clarity, production of corneal discharge or erosion of the cornea. The result is an impaired vision.
Another cause of corneal blindness is the deterioration of the endothelial cells. Without sufficient endothelial cells, the endothelium’s efficiency reduces. The endothelium helps in pumping water out of the cornea’s stroma. A weaker endothelium cannot pump the water efficiently, and so water builds up in the cornea making it swell and so impairing vision.
Keratoconus is also responsible for a significant portion of corneal blindness cases. It results from the middle part of the cornea thinning and so making the cornea bulge outwards. The bulge changes cornea’s curvature, and so distorts its refractive abilities leading to impaired vision.
Most corneal blindness cases arise in poor rural communities where they present a huge problem as lack of awareness coupled with poor financial standing may lead to these people not taking any action to remedy their situation.
Corneal blindness leaves the victim and the society with a massive burden. Vision loss can be devastating to both the blind person and the people around them.
When corneal blindness hits a child, his or her development will be affected. The parents should not take this as an inability to integrate into society and should help the child develop fully by building their self-esteem and confidence and also help them understand and cope with their environment using the remaining senses.
Reduced personal independence may affect the visually impaired if not managed well. Personal independence falls when corneal blindness sets in. The individual should be encouraged to ask for help in cases where they need assistance.
Corneal blindness can be treated through corneal transplants, though this a serious procedure and is often out of reach of patients’ own resources, especially the poor ones.
The transplant involves the diseased cornea being replaced with a healthy one from a deceased donor.
Some cases like those developed from keratoconus do not require a corneal transplant. Vision impairment from keratoconus can easily be corrected by using spectacles. Severe cases do require custom contact lenses, though.
For the many more people suffering to corneal blindness to regain their vision, we need to change our attitudes to organ donation. “We need more people pledging to donate their cornea and more financial donations to support the replacement procedures”, said a representative of the Tej Kohli Cornea Institute in Hyderabad, India.
The number of cornea donations currently cannot support the number of visually impaired individuals that need help. The low numbers could be because of lack of awareness of the problem, cultural stigmatization of donation of body parts and various unique personal reasons.
Consistent and organized campaign to raise awareness about the prevalence and effects of corneal blindness can be good place to start to ramp the donation numbers up.
Restoring the vision of blind person can be one of the most rewarding gifts you can ever give, for both the patient and you.
Vision is a primary sense and losing it can be very devastating to both the visually impaired individual and their loved ones. If the number of people suffering from corneal blindness can be reduced, every possible action should be taken towards that objective.
Most of the causes of corneal blindness are easily preventable and can be remedied if caught before the disease has progressed too far. Creating awareness about corneal blindness will be a bold step towards reducing the number of people who lose their vision every year.
Loved ones of those who have lost their sight should not give up as some cases can be reversed through corneal transplant.