Eye Infections are eye ailments caused by bacterial, viral or fungal agents. There are many different types of eye infections, with different causes and treatments. All parts of the eye are susceptible to infection. Eye infections can affect one or both eyes, and can occur in people of all ages.
Common eye infections
- Pink eye (conjunctivitis)
- Eye stye
- Corneal ulcer
- Pink eye (conjuctivitis)
Pink eye, or conjunctivitis, is a common eye ailment defined as an infection or inflammation of the conjunctiva (the outermost layer of the eyeball), which causes it to become red or pink in colour. Pink eye can be caused by bacterial infections, viruses, allergies, or contact-lens related problems. There may be discharge, which can irritate the eyes further. Often the condition appears in one eye and then spreads to the other. There are several types of pink eye, and most are contagious. Depending on which type you have, symptoms may last between three and ten days.
Pink eye can be contracted through numerous ways. You can contract viral or bacterial conjunctivitis simply by touching your eye after touching an infected surface or object such as a doorknob or shopping cart, or by using infected mascara or eye drops. Shaking hands or sharing towels and pillows with someone who is infected can also result in transmission of the disease.
Other times, pink eye develops as a symptom of a systemic, body-wide disease—for example; pink eye is a symptom of chlamydia. If you are subject to seasonal allergies, you may experience pink eye during times of the year when pollen and other allergens fill the air. Over-use of certain types of contact lenses, such as extended-wear lenses, or improperly cleaning contact lenses can also cause this condition. Learn more about common lens-care mistakes.
Pink eye symptoms
Some symptoms are unique to certain types of pink eye. The most noticeable sign is the pink to reddish colour of the eyes. Irritation and itchiness are two other common symptoms of conjunctivitis. Tearing is another prevalent symptom, as the eyes naturally produce more tears in order to relieve the discomfort.
Some types of pink eye cause discharge, especially viral and bacterial conjunctivitis. This discharge may be yellow or green, and it can cause the eyelids to stick together or it can flow out of the eyes.
Diagnosing pink eye
Diagnosing pink eye usually begins with a complete history and physical examination. Infectious forms of conjunctivitis are diagnosed by their symptoms and appearance. In general, a slit lamp examination is performed. The slit lamp magnifies the surface of the eye and allows the eye doctor to see an inflamed conjunctiva, infected cornea, or infected anterior chamber (the front part of the eye).
Viral conjunctivitis is harder to diagnose, and can be distinguished from bacterial conjunctivitis solely by its appearance, but this form of pink eye is usually accompanied by a cold symptom or a sore throat. Samples may be taken and sent to a laboratory to identify the infectious organism. In most cases, samples are taken when gonorrhoea or chlamydia is suspected, pink eye is severe, or the condition is recurrent.
Prevention of pink eye
Avoiding pink eye is not difficult. Here are some basic ways to prevent pink eye from spreading:
- Wash your hands frequently.
- Use antibacterial hand sanitizer frequently, especially if you are unable to wash your hands with soap and water.
- If allergic conjunctivitis is the problem, remove yourself from the area in which the allergens are present.
- Use cold compresses on your eyes periodically to lessen symptoms, if due to allergies; use warm compresses several times per day for all other types.
- Avoid touching your eyes directly.
- Avoid sharing towels, washcloths, make-up, goggles, sunglasses, eye drops or pillows.
- Keep your eyewear clean at all times.
- Disinfect common household items frequently, especially if a member of the household has pink eye.
- If you have pink eye, discontinue using current contact lenses, make-up, and eye drops, and do not replace or resume using product until condition is gone.
Pink eye treatment
Treatment depends on what type of the disease you have. Pink eye typically resolves without serious complications within a week or two, with or without treatment, although symptoms may last up to six weeks. Other times, such as with allergic conjunctivitis, the condition may disappear after removing the allergen.
For bacterial infections, a doctor must prescribe an antibiotic to attack the bacteria. This medication can be delivered in eye drops or ointments that are applied to the eyes. Pink eye caused by allergies can be treated with over-the-counter anti-histamine allergy eye drops.
Over-the-counter medications are all that is required for most cases of viral pink eye—the virus just needs to run its course, and medication is used just to soothe the symptoms. Antibiotics do not work against viruses. Warm compresses are great for removing the sticky residue around the eyes. If herpes simplex conjunctivitis is present, a doctor may prescribe anti-viral medicines. Some types of conjunctivitis require mild steroids to be applied directly to the surface of the eye. In general, steroids are only used in severe cases.
- Eye stye or hordeolum
Styes, also called hordeola, are bacterial infections that lead to the obstruction of oil-producing glands of the eyelids. Styes appear as small bumps on the upper or lower eyelids. They occur in both sexes and to all ages. Styes are usually harmless and will go away on their own within one to two weeks when your body fights off the infection. To prevent a stye in the eye, always wash your hands before touching your eyes and maintain good eye hygiene, especially if you wear contact lenses.
Many people confuse styes with chalazia. The two types of bumps are similar; the difference is that chalazia develop under the skin and never appear with a head, while styes look like a pimple on the eyelid. Also, a chalazion is usually not painful and usually not accompanied by redness or tenderness.
- Redness accompanied by slight pain and tenderness.
- Swelling that usually appears as a bump. The head of the stye may be on the outer eyelid or underneath the eyelid.
- Discomfort when blinking; gritty feeling in eye.
- Sensitivity to light.
Causes of stye
Styes are caused by a bacterial infection, most often staphylococcal, in a hair follicle or a gland in the corner of the eye. Children frequently get styes from rubbing their eyes with dirty hands. Certain risk factors can increase your chances of developing styes. These risk factors include:
- Previous styes
- Chronic skin problems
Are styes contagious?
Although the stye itself is not contagious, the bacteria that caused it can spread from one person to another. The staphylococcus bacterium lives on the skin and mucous membranes of humans and most animals. Normally, this particular bacterium does not cause problems with the body, but when it enters the oil glands in the eyelids, it can cause pain and inflammation, and it can lead to the development of styes.
In most cases, the bacteria enter the eye area when you rub your eyes with dirty hands. Styes are common in children for this reason. The bacteria block the oil glands, preventing the oil from being secreted, and a stye soon develops. You can pass the bacteria to another person through contact, but the bacteria will not necessarily manifest into a stye.
Diagnosing a stye
A stye will often heal on its own within a couple days. If it does not, you should see your eye doctor for a complete eye exam, to determine whether another eye problem, such as blepharitis, is causing the stye.
A stye can be treated at home or by your healthcare provider. Typically, you will be directed to apply warm compresses to your eyelid, to relieve pain and inflammation. Warm compresses may also accelerate the healing process. Apply the compresses for 10 minutes and repeat as often as needed. Contact lens wearers are asked to refrain from wearing their lenses until the stye and infection are gone. Never squeeze a stye; it will eventually open and drain the pus on its own. If you seek medical treatment, you may be prescribed an antibiotic ointment or cream to fight off the infection.
In most cases, the infection heals on its own, and drainage occurs about two days after the head appears, or within a week of the appearance of symptoms such as tenderness and redness. Styes are usually recurrent, even with treatment, so you should take preventive measures to reduce the risk of recurrence. In some cases, surgical draining of the stye may be necessary to help heal the infection.
Unfortunately there are no specific preventive measures for styes. Keeping your eyelids and eyelashes clean is important. To do this, add three drops of baby shampoo to a small bowl of warm water. Soak a clean cotton ball in the solution, then gently scrub both eyelids for 30–60 seconds with your eyes closed. Rinse with warm tap water. Additional general preventive steps include:
- Avoid sharing eye make-up with others.
- Avoid sharing towels and other linens such as pillowcases and washcloths.
- Visit your eye doctor regularly.
- If you have a medical condition, visit your healthcare provider often, to ensure that your condition is under control.
- Begin treatment as soon as symptoms develop; contact your eye doctor for specific instructions.
- Do not touch or rub your eyes, especially if you have a stye.
Occasionally, complications may develop from a stye. Typically this occurs when preventive measures are not taken. For example, the bacterial infection may spread to other parts of your body, including other glands in the eyelid, if you open the head of the stye before it opens on its own. Another complication of eye styes is their tendency to recur. The infection may not respond well to treatment, which may contribute to frequent recurrence.
Some styes may not open and drain on their own within two days of the head’s appearance. Self-treatment may not be sufficient, and the pain may increase until medical treatment is needed. Contact your eye doctor or healthcare provider immediately, if the stye lasts more than two weeks, or if vision changes occur.
- Blepharitis or eyelid inflammation
Blepharitis is a usually non-contagious and common eye disorder that affects all ages and both sexes, and may be associated with bacterial infection or skin disorders such as rosacea or seborrhoea. It inflames the eyelash follicles along the edge of the eyelid, forming dandruff-like scales on the eyelashes.
Although most experts treat it as a serious condition, blepharitis alone is not known to cause any permanent damage to eyesight. If blepharitis is severe, then related problems affecting the cornea can threaten vision. Eye care professionals usually become aware of the condition in the course of comprehensive eye examinations.
There are many symptoms that may signal the presence of blepharitis or eyelid inflammation. Some of these symptoms are more severe than others, and sometimes a person will not experience any of these symptoms at all. The most common symptoms include:
- Crusty discharge on the lashes or lids, especially when first awakening
- Redness of the eye or eyelids
- Swelling of eyelids and skin around eyes
- Excessive tearing
- Dry eyes
- Blurring of vision
- Loss of eyelashes
- Photophobia (sensitivity to bright light)
- Gritty sensation when blinking
- Fluctuating vision due to secondary dryness and an unstable tear film
Types of blepharitis
Blepharitis can be divided into two sub-types, based on whether it predominantly affects the anterior (front) eyelid structures or the posterior (back) eyelid structures. Some people have predominantly anterior or posterior blepharitis, and some people have both.
- Anterior Blepharitis: This type affects the outside front edge of the eyelid, where the eyelashes grow, and is usually caused by bacteria (staphylococcal blepharitis) or dandruff of the scalp and eyebrows (seborrheicblepharitis). In rare cases, it is caused by allergies or an infestation of the eyelashes by mites or lice.
- Posterior Blepharitis: This type of blepharitis affects the meibomian glands, which are located just within the eyelid margin. There are twenty to thirty meibomian gland openings on each eyelid margin. The inflammation causes thickening of the oil secretions, so that the oil does not flow as well, causing secondary dry eye and chronic inflammation, redness, thickening, and notching of the eyelid margin. This condition may also be referred to as rosacea-associated blepharitis, because it is often seen in people with rosacea.
What Causes Blepharitis?
Blepharitis can develop for a number of reasons. In many cases it is caused either by bacteria or by the skin condition known as seborrhoea, which is similar to dandruff. Other times, it is caused by severe allergies or plugged oil glands and rosacea. Although it is not as common, blepharitis can sometimes be caused by an infestation of the eyelashes by mites or lice.Risk factors may include:
- Exposure to allergens
- Dermatitis of the scalp and other body parts
- Oily skin
- Acne rosacea
- Age (it is commonly seen in the young and elderly)
- Exposure to chemical or environmental irritants like smoke or smog
- Hands that remain dirty for most of the day, such as during a work shift, or poor hygiene
Treatment of blepharitis
Depending on which type of blepharitis you have, there are a variety of ways to treat this condition. With any type of blepharitis, the cornerstone of treatment is keeping the eyes clean and free of debris with hot compresses and gentle lid hygiene.
Warm compresses are a mainstay of all treatments for blepharitis. The heat and moisture can soften flakes and debris on the eyelashes, making them easier to clean. The heat also helps to encourage the flow of oil from the meibomian glands. Blepharitis is a chronic condition, and it is helpful to make warm compresses a part of your daily routine, and to apply them more often when symptoms flare.
After a warm compress, gently massage the eyelid margins to prompt the flow of oil from the meibomian glands.
Gently wash the eyelids and eyelashes with baby shampoo diluted with water, or a commercial eyelid cleanser such as those made by Ocusoft. Wrap a washcloth around your index finger or use cotton swabs to clean. Avoid rubbing too hard, and rinse with warm water when finished.
Additional treatments include:
- Oil containing artificial tears and lubricating ointments to relieve burning, grittiness and secondary dryness.
- Antibiotic drops or ointments.
- Short courses of topical steroid drops for flares (only under a doctor’s supervision).
- Oral antibiotics, especially for posterior blepharitis.
- Using anti-dandruff shampoo/conditioner on the scalp (for patients with seborrheic dermatitis).
- Reducing time spent wearing eye make-up; always take make-up off before bed.
- Discontinuing use of contact lenses until symptoms improve. When a contact lens wearer experiences redness, pain, and/or blurred vision, he or she should always remove the contact lenses and contact his or her eye care provider for advice, as this may signal a more serious issue.
- Avoiding environmental irritants (e.g., dust).
- Taking omega-3 fatty acid supplements, since omega-3 is known to help in the proper function and regulation of the eyelid glands and has an anti-inflammatory effect. Always tell your primary care doctor about any supplements you are taking, as they may interact with other medications you take.
Prognosis of blepharitis
In most cases, symptoms improve with treatment. For most people, the condition is chronic, and symptoms may come and go. Symptoms typically recur once treatment stops. Although symptoms have the potential to be severe, blepharitis is rarely considered a serious condition.
It is extremely important that you see your eye doctor at least once a year. Even if you do not have any symptoms, an eye exam is a great opportunity for you and your doctor to find out if anything is wrong, or if you have a condition such as blepharitis. Additional preventive measures you can take include:
- Keeping the area around your eyes clean with daily warm compresses and gentle lid hygiene.
- Keeping your scalp clean and free of dandruff.
- Treating skin disorders such as rosacea.
- Avoiding dusty or smoky environments whenever possible.
- Avoiding touching or rubbing your eyes, even after washing your hands.
A corneal ulcer is an inflammatory and/or infective condition of the cornea involving a disruption of its topmost epithelial layer down through its middle or stromal layer. The cornea is the clear, protective covering at the front of the eye and is the first part of the eye to focus light. A corneal ulcer can often be the result of an untreated corneal abrasion (a scratch on the cornea). Once an injury or scratch occurs, bacteria immediately begin invading the wound, which leads to infection and corneal ulcers.
Corneal ulcers occur in people of all ages. Typically the ulcer is infectious, but some corneal ulcers are not. Pain, redness, and vision problems are usually associated with ulcers that contain bacteria. Still, all corneal ulcers should be looked at by an eye care professional to ensure that there is no infection and to help craft an appropriate treatment plan.
Corneal ulcer symptoms
Symptoms of corneal ulcers vary from person to person, depending on such factors as the location and size of the ulcer. If the ulcer is caused by bacteria, it may be visible to the naked eye in the form of a white patch on the cornea. Not all corneal ulcers are visible without a microscope, however, especially if they are caused by the herpes simplex virus (discussed further in the causes section of this article). Typically, corneal ulcers cause symptoms such as:
- Pain ranging from mild to severe, but typically severe
- Redness of the sclera and conjunctiva (the white part of eye and its clear cover)
- Photophobia (sensitivity to light)
- Impaired and/or blurred vision
- Watering of the eye
- Clouding of the eye
- Discharge from the eye
- Feeling of foreign body in eye
Causes of corneal ulcers
In most cases, corneal ulcers are caused by germs that enter through a previous injury or scratch to the cornea.
Corneal ulcers are more common in contact lens wearers, possibly due to the rubbing of a dirty or defective lens against the surface of the eye. If enough rubbing occurs, the corneal surface can become weak and break, which enables bacteria to enter the eye and begin reproducing and spreading.
Contact lens wearers who do not practice proper hygiene also increase their risk of developing corneal ulcers. For example, leaving soft contact lenses on while sleeping, or practising poor hygiene, while removing or adjusting the lenses, increases the exposure to bacteria that can lead to infection. Studies have shown that overnight wearing of contact lenses is the biggest risk factor for serious corneal infection.
Acanthamoebae (acanthamoeba keratitis) are common eye parasites. Contact lens wearers who fail to remove their lenses before swimming can contract this parasitic infection. Fungal keratitis can also occur after an injury to the cornea involving plant material, or if your immune system is suppressed.
Additional causes of corneal ulcers may include:
- Eye allergies
- Corneal abrasions
- Eyelids that do not close all the way, such as with Bell’s palsy
- Dry eyes
- Immune system disorder
- Inflammatory diseases such as multiple sclerosis and psoriasis
Diagnosing corneal ulcers
If you experience symptoms of corneal ulcers, you should contact an eye care professional immediately for a complete eye exam. Untreated corneal ulcers can lead to permanent eye damage and vision loss. During the eye exam your eye doctor will look for signs of infection. In cases in which an ulcer is not visible, eye drops that temporarily stain the eye may be used to identify the ulcer. Typically your eye doctor will use a slit lamp (eye microscope) to look into your eye. Regardless of the visibility of the ulcer, a yellow dye may be used to see the affected area more easily. Visual acuity tests and corneal scrapings may be used to determine the cause of the ulcer. Blood tests may be needed to rule out specific disorders and diseases.
Corneal ulcer treatment
In order to treat corneal ulcers, doctors must first determine the cause of the ulcer. Treatment should not be delayed when corneal ulcers develop. If the cause is unknown, antibiotics are prescribed to fight any bacterial infection that may be present. The antibiotics are usually administered in the form of eye drops, sometimes as often as one drop per hour. In some cases, corticosteroid eye drops are prescribed to reduce swelling and inflammation.
If the corneal ulcer is severe, a cornea transplant (keratoplasty) may be needed. During this procedure the diseased or damaged cornea is removed. A new cornea is then grafted onto the eye with tiny sutures (stitches). The sutures are removed after healing is complete, usually several weeks after surgery. Most people see an improvement in their vision within days after the surgery. In some cases, hospital stays as long as two days are required.
Complications of corneal ulcers
Most complications from corneal ulcers occur because the ulcer has been left untreated. Typically, treatment can prevent complications such as:
- Loss of vision
- Scarring on the cornea
- Loss of affected eye due to cataracts or glaucoma
- Spread of infection to other parts of eye and body
Preventing a corneal ulcer
If you have an eye infection or injure your eye, you should seek medical attention immediately from an ophthalmologist or optometrist. Early treatment can prevent the ulcer from developing. Symptoms of corneal ulcers should not be ignored. Contact lens wearers should wash their hands before handling contact lenses in order to prevent the transmission of bacteria and foreign objects. Discontinue wearing contact lenses while you sleep. Talk with your eye-care professional about prevention measures you should take during your normal daily activities
Glaucoma can be regarded as a group of diseases that have as a common end-point a characteristic optic neuropathy which is determined by both structural change and functional deficit. The medical understanding of the nature of glaucoma has changed profoundly in the past few years and a precise comprehensive definition and diagnostic criteria are yet to be finalised. There are several types of glaucoma, however, the two most common are primary open angle glaucoma (POAG), having a slow and insidious onset, and angle closure glaucoma (ACG), which is less common and tends to be more acute.
Prevention and treatment
There is little known about primary prevention of glaucoma. However, there are effective methods of medical and surgical treatment if the disease is diagnosed in its early stage. Through appropriate treatment, sight may be maintained; otherwise the progression of the condition leads eventually to severe restriction of the visual field and irreversible blindness.
Report compiled by Temitope Obayendo with additional information from the World Health Organisation (WHO) Eye Health Web, and All About Vision.