How STIs Can Become Eye Diseases

Sexually transmitted infections (STIs) typically affect the genitals, rectum, and throat but can also spread to the eyes and any other part of the body where there are mucosal surfaces. These are tissues that produce mucus, typically located within canals of the body (such as the nostrils, mouth, lips, urethra, inner foreskin, anus, and vagina).

Mucosal surfaces are also found in and around the eye—including the inner eyelid and surface of the eye known as the conjunctiva—making them easy targets for STI infection.

Mucous membranes are all similar, but not identical, in structure. What they share is a porous structure that allows microorganisms like bacteria and viruses easier access into the body.

Incidence

Eyes can be particularly dangerous sites for sexually transmitted infections and in severe cases can cause eye injury and permanent vision impairment. Even today, eye diseases caused by STIs are a major cause of blindness in some countries.

In the United States, it is relatively uncommon for STIs to cause eye disease in adults. However, they are far more often seen in infants. This is because newborns may be exposed to their mother's STI when they pass through the vaginal canal during birth.

However, as the treatment can cause eye problems, some healthcare providers prefer to test and treat pregnant people for STIs before they give birth to limit antibiotic exposure to the baby.

Types

Not all STIs can become eye diseases. For example, HIV is not transmitted to the eyes, although the virus can sometimes make people more susceptible to eye problems.

Instead, the STIs that can cause eye diseases are the ones that more directly infect the skin and mucous membranes. The four most common types include three bacterial STIs and one viral STI.

Chlamydia

Chlamydia infections of the eye are sometimes referred to as trachoma. This common infection, caused by the bacterium Chlamydia trachomatis, is one of the leading infectious causes of blindness in the developing world. Less severe infections can lead to reduced vision.

Most of the eye problems caused by chlamydia are due to conjunctival inflammation and scarring. Early treatment can prevent the more severe manifestations of chlamydial eye infections. The treatment generally involves antibiotics taken either by mouth or applied directly to the eyes.

In areas where trachoma is common, increasing focus has been placed on facial cleanliness to better prevent eye chlamydia.

Gonorrhea

Gonorrhea of the eye is primarily seen in newborns. In adults, most eye diseases caused by gonorrhea are caused by autoinoculation (when a person touches their own eyes after touching infected fluid or secretions).

Eye disease caused by the bacteria Neisseria gonorrhoeae is also treated with antibiotics, usually delivered by injection. If not treated appropriately, gonorrhea eye disease can lead to vision loss or blindness.

Syphilis

Syphilis of the eye, also known as ocular syphilis, is less common than eye diseases caused by chlamydia or gonorrhea. It is caused by a bacterium known as Treponema pallidum.

However, in 2015, an unusually large number of eye infections caused by syphilis were seen in the United States. These were mostly seen in men who have sex with men, around half of whom were HIV-positive.

Eye infections caused by syphilis can cause redness, blurry vision, and blindness. The recommended treatment is intravenous aqueous penicillin G. This is also the treatment recommended for people with neurosyphilis (syphilis of the central nervous system).

Herpes

Herpes simplex is a virus that can cause eye disease as well as lesions on the face and genitals. Because herpes is not curable, people with herpes eye infections often recur over time, significantly decreasing a person's quality of life.

Vision problems tend to be worse during active outbreaks but can also persist when no lesions are present. Some research suggests that herpes eye diseases are more likely to occur in people who are HIV-positive or have diabetes.

Although eye diseases aren't particularly common with herpes, they can become serious if left untreated. The antiviral drug Zovirax (acyclovir) is typically the first-line course of treatment. It can also reduce the risk of herpes recurrence if used prophylactically.

Acyclovir can also be used to treat eye infections caused by the varicella-zoster virus (VZV), the virus that causes chickenpox and shingles. 

A Word From Verywell

These days, eye diseases caused by STIs are relatively rare in the United States. This is largely due to healthcare providers using preventative measures to prevent transmission at the time of birth.

To avoid transmission in adults (including autoinoculation), avoid rubbing your eyes during or after sex. If you must do so, make certain to wash your hands before touching your face.

And, don't forget to check in with your healthcare provider if you start to have unusual eye symptoms or discharge. Eye infections aren't fun, but they're usually quite treatable with the proper medication.