The Cornea and Ocular Surface

The cornea is the clear outer dome of the eye that allows light to enter and become focused through the lens onto the retina. The cornea is an avascular tissue and receives most of its nutrients from the tears, the air, and fluid inside the eye. Contact lens wear can starve the cornea of oxygen and lead to corneal neovascularization (blood vessel growth), infections, and scarring. It is important to be seen by your eye doctor as soon as you suspect anything out of the ordinary with your eyes.

The ocular surface includes the outer layer of the cornea, the tears, the conjunctiva, and the margin of the eye lids. This part of the eye has the most frequent injuries and ocular disease manifestations due to direct exposure to the environment.

Common Cornea and Ocular Surface Conditions

Conjunctivitis

Conjunctivitis is an inflammation of the conjunctiva, the thin, transparent layer that lines the inner eyelid and covers the white part of the eye. The three main types of conjunctivitis are infectious, allergic, and chemical. Common symptoms of conjunctivitis are red watery eyes, inflamed inner eyelids, blurred vision, an itchy scratchy feeling in the eyes, and sometimes, a pus-like or watery discharge.

To control the spread of infectious conjunctivitis, you should keep your hands away from your eyes, thoroughly wash your hands before applying eye medications, and do not share towels, washcloths, cosmetics, or eye drops with others.

Related Links:

https://www.medinfo.co.uk/conditions/conjunctivitis.html

Corneal Infections

Infection of the cornea and ocular surface are common and can be from several factors. Infection is often from contact lens wear, injury, or from another infected individual. Infections can be caused by many pathogens including bacteria, viruses, fungi, and protozoa. Proper contact lens wear is paramount to reduce the risk of infection. If these infections are not treated early, there can be serious consequences including permanent scarring and vision loss. Medical and surgical treatments are available to reduce permanent damage and vision loss from infections.

Corneal Dystrophies

Corneal dystrophies are a large group of disorders that often have a genetic component to their presentation. Many affect a specific layer of the cornea and result in an opacification or loss of clarity, such as Fuch’s Endothelial Dystrophy. Others affect the shape and structure of the cornea, such as Keratoconus

Keratoconus

Keratoconus causes the corneal tissue to weaken and progressively thins and steepen,s which can distort vision even with glasses. Often, specialty contact lenses are needed to see clearly, and in severe cases, corneal transplantation is required to obtain better vision. There are new treatments that show promise in stabilizing this progression without the need for corneal transplantation surgery in less severe presentations of this disorder.

Related Links:
https://www.allaboutvision.com/conditions/keratoconus.html

Fuch’s Endothelial Dystrophy

Fuch’s Endothelial Dystrophy affects the cornea’s ability to maintain a proper level of fluid internally. This causes swelling of the cornea, which can damage the corneal tissue and lead to vision loss. This dystrophy is caused by a loss of function of the inner layer of the cornea, called the endothelium. It is now possible to improve this dystrophy with a transplantation of just the inner layers of the cornea in a procedure called Descemet’s Stripping Endothelial Keratoplasty or DSEK.

Dry Eye Syndrome

Dry eye syndrome is the most common ocular condition. Common signs of dry eyes include redness, burning/gritty sensation, sharp eye pain, and transient blurred vision. There are several forms of dry eye, caused by different factors. These range from a lack of adequate tear production, inadequate balance of normal tear components, incomplete blinking and lid closure, and more severe causes from autoimmune conditions.

It is important to see your eye doctor if you suspect you have dry eyes, so they can properly diagnose the specific form of dry eye syndrome and treat it accordingly. There are now many palliative and medical treatments available to treat signs and symptoms of dry eye syndrome.

Related Link:
https://www.allaboutvision.com/conditions/dryeye.html