Pink eye is an infection or inflammation that has developed in the conjunctiva, the thin, clear membrane that covers the inside of the eyelids and white part of the eye (sclera). The medical term for pink eye is “conjunctivitis.” Pink eye and conjunctivitis are general terms that refer to the common signs and symptoms experienced in the several different forms of pink eye that can occur.
The most common symptoms and signs of pink eye include redness of the eye or inner eyelid (caused by dilation of the blood vessels within the conjunctiva), increased tearing, mucous or development of pus, irritation or foreign body sensation (“sand in the eyes”), itching, mild eyelid swelling, blurred vision, and crusting of the eyelids upon awakening. The treatment of pink eye depends on the cause.
The primary causes of pink eye are infections (viral or bacterial), allergies, and irritants in the environment. Viral infections are the most common, and they are caused by the same viruses that lead to the common cold. Symptoms usually include redness, watery discharge or mild mucous discharge, and crusting and can last anywhere from a few days to a few weeks. These infections are very contagious, and it is important to maintain good hygiene so as not to spread the infection to others (see below). While one eye may be affected, it is very common for the infection to spread to the fellow eye. Aside from viral infections that may be caused by herpes viruses, there are no eye drops that will cure the infection, just as there are no medications to cure the common cold. Therefore, emphasis is placed on maximizing comfort as much as possible with cold compresses or artificial tears and using gentle lid scrubs to clear crusting.
If symptoms are severe, anti-inflammatory drops can be prescribed by an eye care practitioner to help improve comfort and sometimes to help improve vision. Bacterial infections are highly contagious and cause red eyes, pus, and crusting of the eyelids. Staphylococcus and Streptococcus are bacteria that commonly cause pink eye. These infections often respond nicely to antibiotic drops, and drops are given to quicken the resolution of the infection, prevent eye damage, and reduce the risk of spreading the infection. It may be hard to distinguish, based on the eye examination, between viral and bacterial infections, and sometimes a culture using a sterile swab technique is performed to help in diagnosis and treatment. Allergic conjunctivitis is caused by the body’s reaction to an allergen or irritant, including pollen or other environmental allergens and pet dander. The primary symptoms are itching, redness, and tearing. Sometimes the eyelids can become mildly swollen, as can the conjunctiva itself. Cool compresses, refrigerated artificial tears, and allergy eyedrops can be effective in treating the allergy symptoms. Avoidance of the causative allergens, when possible, is also helpful. Sometimes oral allergy medications can reduce symptoms, although use of these medications can sometimes lead to dry eye. Environmental irritants (smoke, fumes, dust, chemicals, etc.) can also lead to redness, burning, irritation, and tearing. Reducing exposure to these irritants is the primary treatment; protective eye wear can often be helpful.
The key to preventing the spread of infection is practicing good hygiene. Patients with contagious infections need to wash their hands often and avoid touching their eyes with their hands, avoid reusing or sharing towels, washcloths, and tissues, change bed linens frequently, and throw away any used make up or contact lens materials. A special note for contact lens wearers: contact lenses do carry a risk of eye infection, and this risk can be reduced by following professional lens care guidelines. Extended wear of lenses, dryness, dusty/dirty environments, and poor hygiene all contribute to an increased risk of infection, which, if serious enough, can cause permanent vision problems or an inability to wear contact lenses in the future. Make sure to replace lenses and storage cases frequently, do not reuse solution or use expired solution, store contacts in disinfecting solutions, not saline, and avoid contact with water while wearing your lenses. Never wear contact lenses that were not prescribed by an eye care professional.
Click here to read more about contact lens-related eye infections from the Academy of Ophthalmology’s EyeSmart website.