The eyes are the window to the soul — and to a host of travel-related illnesses, according to a new report in a medical journal.
In an article published by Travel Medicine and Infectious Disease, doctors said patients' eye problems could provide important clues to ailments that might be affecting other parts of the body.
"A lot of infectious diseases can cause eye problems," said Dr. Susan Lightman, professor of ophthalmology at Moorfields Eye Hospital in London and lead author of "The Wandering Eye: Eye Infection in the Returning Traveler," which appeared Nov. 30 online.
Some travelers return home with a systemic illness and what seems like an unrelated eye problem, and "the doctor doesn't link the two," said the report's co-author, Dr. William Lynn, infectious disease specialist at Ealing Hospital in London.
"What we are saying is: Don't ignore eye symptoms," Lynn said. "It may be related to something going on in the rest of you."
Dengue fever, for instance, a mosquito-borne illness, often causes fever and muscle pain. But, Lynn said, some travelers also report eye pain, blurred vision or the appearance of halos and "floaters" (semi-transparent or cloudy specks) — symptoms that could help a doctor make a correct diagnosis.
The incidence of dengue fever has risen in the last decade, Lynn said. It's common in Southeast Asia but also has been reported recently in Brazil and the Caribbean, among other areas. Describing all symptoms as well as outlining recent travel destinations could help a patient receive proper treatment.
Toxoplasmosis is another condition that may involve eye problems, Lynn and Lightman said of the parasitic infection that sets in after humans ingest food or water contaminated with cat waste.
Most infected people are not aware of their condition because their immune system keeps the parasite from causing illness, according to the U.S. Centers for Disease Control and Prevention. Often, treatment is not needed; symptoms, which may include muscle aches and pains, disappear in a few weeks or months. For pregnant women and people with weakened immune systems, however, toxoplasmosis can destroy retinal cells or damage the brain and other organs, according to the CDC.
Leptospirosis is a bacterial disease usually caused by swallowing or touching water contaminated with the urine of infected cattle, pigs, horses, dogs, rodents and other animals. Symptoms include muscle aches, fever, chills and vomiting. Sometimes, though, the primary infection is so slight that it goes unnoticed and untreated.
Two years may pass before the disease manifests itself in the eyes, Lightman said. The eyes can become jaundiced, red or inflamed. Treatment involves antibiotics taken orally or, in severe cases, intravenously.
Most eye problems can be attributed not to exotic diseases but to poor hygiene, allergies or other mundane sources. Exposure to pollution or wearing contact lenses too long, for example, can lead to inflammation and infection, said Dr. John Cahill, an emergency physician and director of the tropical and travel medicine clinic at St. Luke's- Roosevelt Hospital in New York.
In all cases, prompt medical attention is key, travel medicine experts said. The bottom line, according to Cahill: "If you come back with irritation to the eye, whether it is red eye, yellowing of the eye or a change of vision, you should seek care with either a tropical disease specialist or an ophthalmologist."
Healthy Traveler appears every other week. Kathleen Doheny can be reached at kathleen firstname.lastname@example.org.