Ophthalmologic Manifestations of Chlamydia

Updated: Jan 04, 2023
Author: Mounir Bashour, MD, PhD, CM, FRCSC, FACS; Chief Editor: Hampton Roy, Sr, MD 



Chlamydiae are obligate intracellular organisms from bacteria that now comprise 3 species. They include the following: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae.

C trachomatis, which is almost exclusively a human pathogen, includes the agents of classic trachoma (ie, serotypes A, B, Ba, C). It also includes the agents of inclusion conjunctivitis or paratrachoma (ie, serotypes D-K). The latter organisms infect the epithelium of mucoid surfaces and were once identified as the trachoma-inclusion conjunctivitis agents (TRIC). Serotypes L1, L2, and L3, the agents that infect tissues deeper to the epithelium and cause lymphogranuloma venereum, also are included.[1]

C trachomatis is the most common cause of chronic follicular conjunctivitis (ie, follicular conjunctivitis lasting for >16-28 d). The organism also causes 3 clinical syndromes, which include the following: trachoma, adult inclusion conjunctivitis, and neonatal conjunctivitis. Trachoma and neonatal conjunctivitis are discussed in other chapters so this discussion is restricted to adult inclusion conjunctivitis.[1]

Adult inclusion conjunctivitis results from C trachomatis serotypes D-K, causing chronic follicular conjunctivitis that can occur in adults or in the neonate. The adult disease is transmitted sexually or from hand-to-eye contact. Gonorrhea is the most common co-infection with adult inclusion conjunctivitis. Rarely, the adult disease is transmitted from eye-to-eye contact (eg, sharing mascara).[1, 2]

This image reveals a close view of a patient's lef This image reveals a close view of a patient's left eye with the upper lid retracted in order to reveal the inflamed conjunctival membrane lining the inside of both the upper and lower lids, due to what was determined to be a case of inclusion conjunctivitis, a type of conjunctival inflammation caused by the bacterium, Chlamydia trachomatis. Inclusion conjunctivitis, also known as chlamydial conjunctivitis, is more common in newborns. Symptoms include redness of the eye(s), swelling of the eyelids, and discharge of pus, usually 5 to 12 days after birth. Image courtesy of Susan Lindsley, Centers for Disease Control and Prevention.

Also see the Medscape Reference article Chlamydial Genitourinary Infections.


The epidemiology of this disease revolves around sexual contact. Modes of transmission include orogenital activities, hand-to-eye spread of infective genital secretions, and even direct ejaculate into the eye.[3] Although rare, eye-to-eye contact spread has been reported (eg, sharing mascara). The incubation period is 4-12 days.



United States

It is estimated that 1 in 300 patients who have genital chlamydial disease develop adult inclusion conjunctivitis.


No difference in frequency of disease between the sexes has been reported.


Usually, this condition is observed in the young sexually active population. It is most common in persons aged 15-35 years.


Prognosis is excellent with treatment.

Patient Education

Educate patients about the risks of sexually transmitted diseases and safe sexual practices.

For patient education resources, see the Sexually Transmitted Diseases Center, as well as Sexually Transmitted Diseases and Chlamydia.




Adult inclusion conjunctivitis presents as a unilateral (or less commonly bilateral) red eye with mucopurulent discharge, marked hyperemia, papillary hypertrophy, and a predominant follicular conjunctivitis.

Women often have a concomitant vaginal discharge secondary to chronic vaginitis and/or cervicitis. Men may have symptomatic or nonsymptomatic urethritis.

Conjunctivitis often is chronic and may last for many months.

Inquire about duration of symptoms, prior treatment, and recent and not-so-recent sexual exposure.


Inferior tarsal conjunctival follicles are obvious, and a tender enlarged preauricular lymph node is common.

Keratitis may develop during the second week after onset.

Corneal involvement includes a superficial punctate keratitis, small marginal or central infiltrates, epidemic keratoconjunctivitis (EKC)–like subepithelial infiltrates, limbal swelling, and a superior limbal pannus.[4] The subepithelial infiltrates tend to be more peripheral than after EKC.

Untreated disease has a chronic remittent course, and keratitis and possibly iritis occur more commonly in the late stage of disease.


Adult inclusion conjunctivitis is a sexually transmitted disease.





Laboratory Studies

Laboratory studies include the following:

Diagnosis of chlamydial eye infection is based on clinical appearance and laboratory tests.

Giemsa staining: Basophilic intracytoplasmic epithelial inclusion bodies are seen with Giemsa staining of conjunctival scrapings.

Chlamydial cultures of conjunctiva

Direct immunofluorescent (DFA) staining of the conjunctival scrapings is also useful (Syva MicroTrak).

Enzyme-linked immunosorbent assay[5]

  • MicroTrak (Syva Company)

  • Chlamydiazyme (Abbott Laboratories)

  • EIA (Pharmacia)

  • Kodak SureCell Chlamydia Test Kit (Kodak)

Serum immunoglobulin G (IgG) titers to Chlamydia species may be obtained.

Other Tests

Complete sexually transmitted disease workup of patient and partners is indicated.

Histologic Findings

Basophilic intracytoplasmic epithelial inclusion bodies are seen with Giemsa staining of conjunctival scrapings.



Medical Care

Simultaneous treatment of all sexual partners is important to prevent reinfection. It also is prudent to examine all sexual partners for other venereal diseases, such as gonorrhea, syphilis, and HIV. It may be wise to treat all members of the household with antibiotics.[6]

Treatment consists of systemic antibiotics; topical antibiotics are relatively ineffective in the treatment of this eye disease. Recommended treatment, which is given for 3-6 weeks, includes oral tetracycline (500 mg qid), oral doxycycline (100 mg bid), or oral erythromycin stearate (500 mg qid). An alternative that is less recommended than in previous years due to increasing resistance is azithromycin given as a single dose of 1 g, which can be increased to 2 g if Neisseria gonorrhoeae is suspected. Tetracyclines are avoided in children younger than 7 years and in women who are pregnant or breastfeeding.

Conclusions from a 2013 study show single-dose azithromycin should be considered as reliable as long-term alternative regimens for adult inclusion conjunctivitis. Patients should wait for 1 week until the first signs of significant regression become obvious and should consider approximately 1 month to total relief. Follicles could be reasonably used as a key sign for clinical assessment of treatment success[7]  as written above the increasing resistance makes this not a first choice at present.

Also see the clinical guideline summary, Conjunctivitis, from the American Academy of Ophthalmology,[8] and one from the US Preventive Services Task Force, Behavioral counseling to prevent sexually transmitted infections: U.S. Preventive Services Task Force recommendation statement.[9]


Infectious disease specialist or sexually transmitted disease clinic as necessary


No sexual activity until the course of treatment is complete.


Patients should follow safe sexual practices, including the use of condoms.

Long-Term Monitoring

Patients should be observed 2-6 weeks after initiation of treatment, depending on the severity of the initial symptoms.



Medication Summary

The goals of pharmacotherapy are to reduce morbidity and to prevent complications.


Class Summary

Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.

Tetracycline (Sumycin)

Mainly bacteriostatic; inhibits bacterial protein synthesis by binding to 30S and to some extent 50S ribosomal subunits. They also may alter cytoplasmic membrane leading to leakage of intracellular components such as nucleotides from the cell.

Erythromycin ethylsuccinate (E.E.S., EryPed)

Macrolide antibiotic; inhibits protein synthesis by binding reversibly to 50S ribosomal subunits of susceptible microorganisms. Effect may be either bacteriostatic or bactericidal depending on sensitivity of the microorganism and concentration of the drug.

Clarithromycin (Biaxin)

Exerts antibacterial action by binding to 50S ribosomal subunit of susceptible bacteria and suppressing protein synthesis.

Azithromycin (Zithromax)

Azalide subclass of macrolide antibiotics, derived from erythromycin. Acts by binding to 50S ribosomal subunit of susceptible microorganisms and, thus, interferes with microbial protein synthesis. Nucleic acid synthesis is not affected.

Doxycycline (Doryx, Bio-Tab, Vibramycin)

Inhibits protein synthesis and thus bacterial growth by binding to 30S and possibly 50S ribosomal subunits of susceptible bacteria. Usual doses of doxycycline may be used in patients with impaired renal function.