What is the cornea?

The cornea is a transparent outer tissue that covers the iris and the human eye. It consists of five layers and is covered with tears that protect it from microbes and provide it with food.

The cornea has two important functions:

 -First: protect the eyes from dust and microbes

-Second: It acts as a collecting surface for light rays until it falls on the lens of the eye and then gathers in one point on the retina to give a clear image.

What are the diseases that affect the cornea?

One of the most famous injuries that occur to the cornea and affect its efficiency is the presence of a foreign body in the eye or a laceration in the tissues and layers of the cornea as a result of exposure to get infected keratoconus is also one of the most common genetic diseases that affect the cornea and reduce visual acuity and is initially treated with contact lenses or Medical glasses and it can end up with a corneal graft to maintain the strength of vision in the eyes.

How does the injury occur?

The factors that lead to the occurrence of injury:

-chemical agents.

-yellowness.

-Diseases of the tissues of the eye, such as (Steven Johnson Syndrome).

-Chronic eye infections.

-Weakness in the fifth nerve, which is responsible for the sensation of the cornea.

-All of these factors eventually lead to the growth of blood vessels in the cornea and the loss of transparency of the cornea, and thus weakness severe in vision.

What is meant by corneal transplant?

Corneal transplant is one of the most successful ophthalmology surgeries, which reach 90%.The importance of corneal transplantation is to create a tissue that has transparency and thus maintain visual acuity.

 

Cases in which corneal transplantation is used

-All kinds of ulcers

-advanced keratoconus

-Injury or injury

-corneal clouds

What is meant by defects of visual acuity?

Visual impairment is divided into:

-Nearsightedness

-Farsightedness

-astigmatism

-Vision impairment due to aging

What is the Nearsightedness?

Research has shown that about 1/3 of the population suffers from Nearsightedness.

Reasons:

-The lack of light amplitude in one point in front of the retina due to the large size of the eye

-Symptoms: headache or occurrence around the eye, especially while driving a car or reading for a long time cure it Non-surgical treatment: glasses. Contact lenses

Surgical treatment: LASIK.

What is meant by long-sightedness?

Farsightedness occurs in about ¼ of the population

Causes: The light rays do not gather at one point on the retina, and the light rays gather at a point behind the retina, which causes blurring.

Symptoms: headache or occurrence around the eye cure it.

Wound treatment: using surgical laser.

Non-surgical treatment: glasses or contact lenses.

What is meant by astigmatism?

Symptoms: People with a small percentage may not notice it, but if it is not corrected

Severe astigmatism feels headache and pain in the eye with blurred vision

Treatment: Astigmatism can be corrected using an excimer laser, especially for the regular and mixed types

Regular astigmatism occurs when light rays fall on more than one point (location) on the retina

This causes the surface of the cornea to not rotate completely, which leads to blurring of vision and astigmatism

In cases of short and long-sightedness

It is divided into several types: regular – irregular – mixed

What is double vision associated with age?

Low vision associated with age is a natural symptom with increasing age, especially after the age of forty, and it can be corrected Wear glasses while reading.

What is Keratoconus?

The normal intraocular pressure causes the thin cornea to gradually bulge outward, which changes the shape of the spherical cornea.

This change of shape leads to a negative effect on the strength of vision and vision.

In some severe cases, this may lead to the inability to perform daily tasks such as reading, driving, etc.

Although this condition does not lead to complete blindness, it may lead to the inability to work in 20% of cases require corneal graft surgery to restore vision.

How does keratoconus affect vision?

In the early stages, a slight change in visual acuity occurs, after which the level of vision begins to fluctuate, and the patient needs to change his eyeglasses or contact lenses.

Apply repeatedly and at frequent intervals

The more outwardly bulging the cornea, the sharper the cone and the greater the amount of scattering of the light rays entering the eye, resulting in what is called astigmatism.

Regularly leads to visual impairment in a way that cannot be corrected with regular glasses

At this stage, it is necessary to use hard contact lenses. In the advanced stages, the use of glasses and hard lenses becomes tiring and useless.

A cloud, opacity, or ulcer forms on the surface of the cornea, and hydrocephalus of the cornea can occur, and then vision is greatly reduced.

In 20% of patients, corneal transplant surgery is required to treat advanced cases, and then another treatment method or some visual aids are required other to correct vision properly.

What are the symptoms of keratoconus?

-Blurring in the eye and changing the size of the glasses at frequent intervals

-Increased sensitivity to light

–Difficulty driving at night

-Eye fatigue

-Headache and pain around the eyes

-Eye irritation and severe itching

How can diagnosing keratoconus?

-Consultation with an ophthalmologist.

-Complete eye examination.

-The measurement of the optical error determines its type and the degree of response to simple lenses.

-pachymetry is a measurement of the thickness of the cornea.

-Computerized corneal scan.