Patients present with follicles on the eyelids and a thin, watery purulent discharge from both eyes. There is ocular pain, redness (hence the name pink eye) and eyelid and periorbital edema. Patients often complain of difficulty in opening the eyes in the mornings and pain upon straining the eyes. A study conducted about presenting symptoms of conjunctivitis in 2013 revealed that ocular complains such as itching, tearing, photophobia and discomfort of the eyes lead most of the patients to be diagnosed of allergic conjunctivitis [7].

Laboratory tests

• Complete blood count
• Conjunctival scrapings and culture
• Eversion of eyelid at slit lamp
• Blood culture
• Tests for STDs if genital symptoms are also present

Imaging 

Imaging studies are not required to diagnose conjunctivitis. Orbital CT scan, MRI and a colour Doppler exam may be done to rule out other diseases.

Test results

Conjunctivitis is easily diagnosed with the help of a clinical examination. Laboratory tests may be done to confirm the diagnosis and identify the causative organism.

Benign cases of conjunctivitis usually do not require pharmacologic treatment as they tend to resolve on their own. Almost all the patients that suffer from bacterial conjunctivitis have a self-limiting condition and no treatment is required in uncomplicated cases. That said, it should be noted that conjunctivitis which is caused by such organisms that typically cause venereal diseases like chlamydia, and conjunctivitis occurring in optic lens wearers should be treated with appropriate antibiotics [8]. Medication is not required for viral conjunctivitis as the condition is mild, of short duration and seldom has any lasting effects.

The drugs that may be used include non steroidal anti-inflammatory drugs and glucocorticoids. Glucocorticoids suppress the late-phase reaction of allergic inflammation and are effective in treating bacterial conjunctivitis [9]. Antihistamines are only used for chronic conjunctivitis only because full efficacy is reached after 5 to 14 days after therapy and therefore these medicines are not useful for relieving acute symptoms of conjunctivitis [10]

Conjunctivitis has an excellent prognosis and often resolves spontaneously when the infection has run its course. It is also completely and effectively treated with the help of antibiotics and anti-inflammatory drugs.

Conjunctivitis is due to a bacterial, viral or fungal infection. Viral conjunctivitis is the most common overall cause of infectious conjunctivitis and usually does not require treatment; the signs and symptoms at presentation are variable. Bacterial infections are the second most common cause of conjunctivitis. Strains of the common human pathogen Streptococci pneumoniae lacking the capsule are the main virulence factor. This is the target of current vaccines [2]. Other bacteria that can cause conjunctivitis include Chlamydia trachomatis, Neisseria gonorrhoeae. A cross sectional descriptive study conducted on patients with acute conjunctivitis found that Chlamydia trachomatis accounts for one third of the cases of acute conjunctivitis [3].

Non-infectious causes of conjunctivitis include allergic agents like pollen grains and other particulate matter that enter and settle in the inner surface of the eyelids adjacent to the conjunctiva. This will cause local irritation and itching and inflammation, that manifest as conjunctivitis.

Incidence

Ocular allergy is estimated to affect at least 20 percent of the population on an annual basis, and the incidence is increasing [4]. According to a study, 4.4% out of a total of 1079 observed patients with ocular allergy had acute conjunctivitis [5].

Sex

Conjunctivitis is known to occur equally in both sexes.

Age

Conjunctivitis does not have a predisposition to any particular age group, however the age of patients of conjunctivitis is relevant in identifying the causative agent. For example, a young, sexually active person is more likely to be suffering from conjunctivitis from a sexually transmitted disease (STD).

The factors responsible the conjunctivitis and iritis associated with acute ocular infection and post enteric inflammatory disease are not fully known [6]. It is known however that the inflammatory markers and mediators such as leukotrienes, interleukins and cytokines play an important role in the development of conjunctivitis. When any irritant, be it in the form of virus, bacteria or a particulate matter enters and settles inside the eyelid, adjacent to the conjunctiva, it causes irritation of the conjunctiva. If the irritant remains there for sufficient time, and the person is unable to dislodge it with tearing and/or rubbing, inflammation begins.

Another pathway is the internal pathway where the causative agents, usually microbes such as the ones causing STDs, enter into the orbital blood supply and start to multiply in the orbital cavity, resulting in inflammation. Or the person may already be suffering from an infection such as an upper respiratory tract infection and the infectious agents may infect the eye as well, either due to direct contact such as rubbing the eyes with unclean fingers or through circulating antigens in the blood.
Whatever the initial route or pathway maybe, the end result is same: inflammation. Although the outer epithelial layer provides some defence, it is easily torn or broken and conjunctivitis develops.

Conjunctivitis may be prevented by maintaining good hygiene of the eyes. Regular testing for STDs in sexually active people is recommended and the patients suffering from upper respiratory tract infections or other easily transmissible infections should take appropriate treatment to eradicate the disease from their body.

Conjunctivitis is an inflammation of the conjunctiva, which is an outer transparent covering of the eyeball. It is also known as the ‘Pink Eye’ in many regions of North America [1]. It is a common condition and is seldom reported due to its mild nature. However, not all cases are benign and some may leave serious damage and lasting ill effects if not treated adequately with appropriate antibiotics.

Definition

Conjunctivitis is a condition in which inflammation of the conjunctiva, which is a membrane coating the eyeball and the inner surface of the eyelids, takes place.

Cause

It is most often due to a viral or bacterial infection but sometimes, the entry of tiny particulate matter, eyelashes, dust, pollen grains, etc can also cause conjunctivitis.

Signs and symptoms

Signs and symptoms include redness of the eye with watery, purulent discharge. There may be slight puffiness and swelling of the eye, pain on straining or exposure to bright lights, itching and burning. 

Diagnosis

Diagnosis is made clinically and is supported with laboratory tests.

Treatment

Treatment is mainly supportive, particularly in cases of viral conjunctivitis. If the condition is due to a foreign particle in the eye, it should be removed so that the eye can heal. If there is a bacterial infection, antibiotics and anti-inflammatory drugs may be used.

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