May 2018


Navigating the red eye
Perspectives on pink eye

by Liz Hillman EyeWorld Senior Staff Writer

Bacterial conjunctivitis (left) presents with a more oozy discharge that can crust over, while viral conjunctivitis (right) is characterized by a more watery discharge and severe inflammation.
Source: Francis Mah, MD

Diagnosing, treating, and preventing spread of viral and bacterial conjunctivitis

Apatient comes into the clinic with red, irritated eyes. Perhaps there is a goopy or watery discharge and some swelling. It seems like the patient has pink eye, but what kind?
At least among the general public, the term “pink eye” has become synonymous with infectious conjunctivitis, either viral or bacterial, said Francis Mah, MD, director of corneal and external disease and co-director of refractive surgery, Scripps Clinic, La Jolla, California. He acknowledged, however, that there are a lot of different conditions that could cause redness or inflammation of the eye beyond a bacterial or viral infection.
For the purposes of this article, experts focused on the diagnosis and treatment of the more common bacterial and viral infectious conjunctivitis.

Differentiating between the two

A big symptom that differentiates bacterial from viral conjunctivitis is the discharge. Dr. Mah said bacterial conjunctivitis is associated with a thicker, goopy discharge that can cause the eyelids, in some cases, to stick together, while viral conjunctivitis causes a more watery, teary discharge.
In addition, he said that inflammation is more prevalent and pronounced with viral infections. Other factors to consider, according to Dr. Mah, are the patient’s age and whether the infection is binocular or monocular.
“In general, children are associated more with bacterial conjunctivitis, whereas older patients [10 years or older] are associated more with viral conjunctivitis,” Dr. Mah said, explaining that he thinks this is likely due to a more developed immune response.
Viral conjunctivitis is also generally more contagious and thus more likely to spread to the other eye.
“Normally what happens with viral is one eye starts it off and because it’s so contagious, a day or two later, it goes to the second eye, and generally the second eye’s reaction is not as severe,” Dr. Mah said.
If the patient experiences chronic or recurrent conjunctivitis, David Verdier, MD, Verdier Eye Center, Grand Rapids, Michigan, recommended consideration of herpes simplex virus (HSV), noninfectious dry eye, acne rosacea, or exposure and/or neurotrophic involvement as the possible cause.

Knowing when it’s EKC

Epidemic keratoconjunctivitis (EKC) is an extremely contagious and more severe form of viral conjunctivitis, which presents with even more severe inflammation and other hallmark features.
While Dr. Mah said any virus that can cause an infection in humans could cause a case of conjunctivitis, there are specific types of adenoviruses that are associated with EKC.
“With EKC, you have a lot more inflammation around the eyes, a lot more symptoms, but one of the key factors that differentiates EKC from others, besides the severe nature of inflammation, is people can develop membranes. Membranes are this tenacious exudate that’s on the conjunctival surface, usually the palpebral conjunctival surface, or the under surface of the eyelids,” Dr. Mah said.
EKC can also cause corneal subepithelial infiltrates (SEIs). Dr. Mah said SEIs usually appear after the infectious period while membranes appear earlier in the disease process.
Christopher Starr, MD, director of refractive surgery and director of the cornea, cataract, and refractive surgery fellowship program, Weill Cornell Medical College, New York-Presbyterian Hospital, New York, said he uses AdenoPlus (Quidel, San Diego), a testing kit that can confirm adenoviral conjunctivitis, on all patients suspected of having acute viral or bacterial conjunctivitis.
“When positive, it confirms the diagnosis and allows me to be confident that not prescribing an antibiotic is appropriate,” Dr. Starr said.

Treatment plans

Treatment of pink eye depends on its etiology, Dr. Verdier said, noting that one should be sure to not overlook possibilities of dry eye, blepharitis, acne rosacea, lagophthalmos or lid anomalies, or neurotropic conditions, which should be treated appropriately in accordance with the condition.
Dr. Mah said when it’s clear it’s a bacterial infection, he is quick to prescribe antibiotics. Research has shown that antibiotics are often inappropriately prescribed in some conjunctivitis cases.1 Other research has shown that bacterial conjunctivitis is self-limiting and antibiotics could be avoided in those cases, too, but antibiotics can at least shorten the duration of the infection.2
“I think it’s prudent for the patient to begin antibiotic eye drops, and generally what I’ll prescribe is a fluoroquinolone,” Dr. Mah said, explaining that he’ll start patients on a drop every hour or two, then taper to 3–4 times a day over a 5- to 7-day period.
Viral conjunctivitis, without a specific medical therapy, is more supportive in nature. This to Dr. Mah means encouraging the use of artificial tears and lubricating eye drops and educating the patient on appropriate hygiene to avoid spread (washing linens frequently, not sharing towels, keeping common items like a TV remote disinfected, and avoiding touching one’s eyes). If there is inflammation, a steroid drop could be used, but Dr. Mah cautioned that while it could help the symptomatology, studies have shown steroid drops can prolong the viral shedding, making the infectious process worse.
Dr. Mah’s treatment plan for EKC depends on the stage the patient is at. If the condition is relatively mild at the time without membranes, he tells the patient that, unfortunately, the symptoms will likely get worse before they get better. Patients need to be cognizant of their hygiene to prevent an epidemic within their home, school, or workplace, and should stay away from public places for about a week while the virus runs its course.
If the patient is already presenting with membranes, Dr. Mah thinks it is important to remove them because they could cause scarring of the conjunctiva. “Most of the time when you remove the membranes, it’s uncomfortable in the office, but [patients] go home and feel a lot better,” he said.
Patients with membranes often have severe inflammation, for which Dr. Mah will prescribe steroids, along with a recommendation for off-label use of ganciclovir gel. Ganciclovir is approved by the U.S. Food and Drug Administration for HSV keratitis, but there have been studies that show its efficacy against adenoviral conjunctivitis.3
Overall, Dr. Mah said the course for infectious EKC is about 7–10 days; after that timeframe is when SEIs might appear. SEIs, which can cause a foreign body sensation and blurred vision, are the result of the body’s cells getting rid of dead virus particles, Dr. Mah said. He said the normal course of treatment is observation, but if the SEIs are visually significant, steroid drops like loteprednol can be effective.
“The tough part is tapering off the steroids; you have to do a slow taper, otherwise the SEIs come right back,” he said.
Dr. Starr said he will remove membranes if they are causing a foreign body sensation or corneal staining. Doing this, however, often strips goblet cells and leads to post-viral ocular surface disease, which Dr. Starr said leads him to start patients on topical anti-inflammatory medications, such as Lotemax (loteprednol, Bausch + Lomb, Bridgewater, New Jersey) in the short term and Restasis (cyclosporine, Allergan, Dublin, Ireland) or Xiidra (lifitegrast, Shire, Lexington, Massachusetts) in the long term. Dr. Starr also said these latter medications can be used off-label for long-term suppression of visually significant SEIs, in addition to steroid pulses.
Dr. Verdier said povidone iodine could be considered for EKC treatment. It doesn’t carry much risk or expense, and it has shown promise against EKC infections in some studies.4 Dr. Verdier tends to leave pseudomembranes alone in EKC patients, treating them with topical steroids instead. He will treat post-EKC dry eye with ocular lubricants and will consider off-label use of cyclosporine or tacrolimus for SEIs.

Preventing spread in the office

Given the highly infectious nature of these conditions, hygiene and disinfection at the clinic is just as important as actions taken at home to prevent nosocomial spread.
“In our clinic we treat anyone who is suspicious for an infection in the same way,” Dr. Mah said. “The rooms get shut down. You can’t put another patient in that room until it has been cleaned. We clean them with disinfecting wipes and clean anything that the patient could have touched in the room.”
If there are epidemics of adenovirus EKC, Dr. Mah said patients coming in with red eye won’t even stop in the waiting room but will be transferred straight to a “red eye room,” which allows staff to isolate infectious agents. This practice has been shown to be effective. For example, in 1985 a quarter of the patients with EKC seen at the Illinois Eye and Ear Infirmary within a 6-month timeframe had acquired the infection at a clinic.5 According to a retrospective report about the epidemic, initial strategies to prevent nosocomial spread were not successful. After the clinic initiated a triage effort where rooms and staff were designated only to infectious patients, nosocomial transmission stopped.

Not to be confused with …

There are a few other conditions that should not be confused for a case of viral or bacterial conjunctivitis. In terms of severity and the potential for vision loss, these include HSV and herpes zoster ophthalmicus (HZO).
HSV, Dr. Mah said, is usually monocular and presents with an ulcerative blepharitis, which can help differentiate it from conjunctivitis.
“The eyes might be red, eyelids red and swollen, but if you have an ulcerative blepharitis, if it’s been treated for awhile and it’s not getting any better, you might want to think of HSV. You don’t necessarily have to have the corneal findings,” he said.
HZO related to shingles would be harder to miss, Dr. Mah said, due to the patient likely having a history of a rash or still presenting with a rash.
“It’s harder to miss, but you don’t want to miss either of these because both can cause permanent vision issues,” Dr. Mah said.
Blepharitis and allergic conjunctivitis could be confused with a bacterial or viral infection as well, Dr. Mah added.
Dr. Verdier also listed several conditions that shouldn’t be confused as bacterial or viral conjunctivitis including fungal infections, Acanthamoeba, microsporidia, and neoplasia (including squamous cell or sebaceous carcinoma).


1. Shekhawat NS, et al. Antibiotic prescription fills for acute conjunctivitis among enrollees in a large United States managed care network. Ophthalmology. 2017;124:1099–1107.
2. Sheikh A, et al. Antibiotics versus placebo for acute bacterial conjunctivitis. Cochrane Database Syst Rev. 2006:CD001211.
3. Yabiku ST, et al. Ganciclovir 0.15% ophthalmic gel in the treatment of adenovirus keratoconjunctivitis. Arq Bras Oftalmol. 2011;74:417–21.
4. Pelletier JS, et al. A combination povidone- iodine 0.4%/dexamethasone 0.1% ophthalmic suspension in the treatment of adenoviral conjunctivitis. Adv Ther. 2009;26:776–83.
5. Warren D, et al. A large outbreak of epidemic keratoconjunctivitis: problems in controlling nosocomial spread. J Infect Dis. 1989;160:938–43.

Editors’ note: Dr. Mah has financial interests with Shire, Okogen (San Diego), IVIEW Therapeutics (Doylestown, Pennsylvania), Bausch + Lomb, and Allergan. Dr. Starr has financial interests with Allergan, Shire, Bausch + Lomb, Alcon (Fort Worth, Texas), and Rapid Pathogen Screening (Sarasota, Florida). Dr. Verdier has no financial interests related to his comments.

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