Chlamydial conjunctivitis, a specific type of “pink eye,” is an inflammation of the eye’s outer membrane. This infection stems from the bacterium Chlamydia trachomatis, which typically causes sexually transmitted infections. While it is more prevalent in young, sexually active adults, this condition can also affect newborns.
Causes and Transmission
Adults generally acquire chlamydial conjunctivitis through autoinoculation, the transfer of Chlamydia trachomatis from their own genital area to their eyes. This typically occurs via contaminated hands after touching infected secretions. A concurrent genital chlamydial infection is frequently present, even if it remains without noticeable symptoms. In rare instances, exposure to inadequately chlorinated swimming pool water can also lead to infection.
Newborns contract chlamydial conjunctivitis during birth. This happens when they pass through the birth canal of a mother who has an untreated Chlamydia trachomatis infection in her cervix. Symptoms in infants generally emerge within 5 to 14 days after delivery.
Recognizing the Symptoms
Symptoms of chlamydial conjunctivitis in adults typically develop gradually, often appearing between 2 and 19 days after exposure. Individuals may experience a sticky or watery discharge from the eye. The white part of the eye often appears red due to inflamed blood vessels, and the eyelids may swell.
Patients might also report an irritating or gritty sensation in the eye, similar to having a foreign body present. Sensitivity to light, known as photophobia, is another common complaint.
While symptoms often begin in one eye, the infection can spread to the other eye within a few days. Unlike many common forms of viral or bacterial “pink eye,” chlamydial conjunctivitis tends to be more persistent and can last for several weeks or even months if it is not treated.
Diagnosis and Treatment
Diagnosing chlamydial conjunctivitis begins with a thorough physical examination of the eye by a healthcare professional. To confirm the presence of Chlamydia trachomatis, a sample is collected using a conjunctival swab. This swab scrapes the inner lining of the lower eyelid to gather epithelial cells, as the bacteria primarily reside within these cells rather than solely in the eye discharge.
The collected sample is then sent to a laboratory for specialized testing, most commonly a Nucleic Acid Amplification Test (NAAT). NAATs are highly sensitive and can detect the genetic material (DNA or RNA) of Chlamydia trachomatis, providing a definitive diagnosis.
While older methods like Giemsa staining can be used, NAATs are preferred due to their accuracy and efficiency.
Treatment for chlamydial conjunctivitis requires systemic antibiotics because topical eye drops alone are typically insufficient to eliminate the infection. For adults, common oral antibiotic regimens include a single 1-gram dose of azithromycin or 100 milligrams of doxycycline taken twice daily for seven days. This systemic approach treats not only the eye infection but also any concurrent genital infection, which is often present.
Newborns diagnosed with chlamydial conjunctivitis are usually treated with oral erythromycin, administered at 50 milligrams per kilogram of body weight per day, divided into four doses, for 14 days. An alternative for newborns is oral azithromycin, given as a single 20-milligram per kilogram dose daily for three days.
It is important to treat any sexual partners of infected adults as well, to prevent reinfection and further spread of the bacterium.
Potential Complications
Leaving chlamydial conjunctivitis untreated can lead to persistent and chronic infection. Over time, this ongoing inflammation can result in significant damage to the eye’s structures.
A notable complication is the development of pannus, where blood vessels and fibrous tissue grow onto the cornea. This vascularization can lead to corneal scarring, which impairs the clarity of vision.
In severe or prolonged cases, the scarring can become extensive, potentially resulting in permanent vision loss or even blindness.
For newborns, an untreated eye infection poses a risk of the bacteria spreading beyond the eyes to other areas, most notably the lungs. This can cause chlamydial pneumonia, a serious respiratory infection that affects between 10% and 20% of infected infants.