Pink eye, or conjunctivitis, is the inflammation of the conjunctiva, which is the thin, invisible membrane lining the surface of the eye. Ordinarily, the tiny vessels that supply blood to this membrane aren’t visible unless there is inflammation, in which case they become visibly enlarged. Conjunctivitis is not to be confused with a blown pupil, which is when a blood vessel bursts and bleeds visibly within that space.
Types, Causes and Symptoms of Pink Eye
Bacterial conjunctivitis is very infectious and is spread from direct contact with secretions from the affected eye. Keep in mind that bacteria can live on surfaces or contaminated objects for quite some time. Outbreaks are common in military barracks, college campuses, and individual family homes.
- Typically begins in one eye and eventually spreads to both eyes
- People often complain of their affected eye being “stuck shut,” especially in the morning
- Discharge from the eye continues throughout the day
Viral conjunctivitis is also very infectious and similarly to bacterial conjunctivitis, it is spread from direct contact with secretions from the affected eye. Viruses can also live on surfaces or contaminated objects, albeit for less time than most bacteria. Outbreaks are common in schools and among children.
Symptoms can be difficult to distinguish from allergic conjunctivitis.
- Patients will often complain of a bumpy, gritty, sandy, or burning sensation in the affected eye.
- There is often discharge, but it’s thinner than that of bacterial conjunctivitis.
Allergic conjunctivitis is not caused by a virus or bacteria but rather by airborne allergens (i.e. pollen, dust, dander, etc.).
- It’s often difficult to distinguish between allergic conjunctivitis and viral conjunctivitis because the symptoms are so similar.
- People will often have the symptoms for months and months in conjunction with allergy symptoms, such as sinus congestion, runny nose, sneezing, and/or wheezing.
The common cause of toxic conjunctivitis is from a preservative in regularly used eye drops (more common) or an allergic reaction to the active ingredient in the eye drop itself, leading to long-term inflammation. Talk to your doctor about switching to an eye drop that doesn’t contain the irritating preservative.
Symptoms can be difficult to distinguish from other conjunctivitis.
- Patients will often complain of a dry or gritty sensation in the affected eye.
- There will be no discharge from the eye. This is the predominant different between the infectious types of conjunctivitis.
- Patients will often complain that they use eye drops for their dry eyes but it just seems to make it worse or it has no effect at all. This is a sign that the patient might be reacting to the preservative.
How Is Pink Eye Diagnosed?
In order to diagnose and distinguish your pink eye from rare and more serious conditions (not listed in this article), speak with your physician.
The questions that your doctor will ask to diagnose your conjunctivitis include:
- Do you have morning crust, daytime redness, or discharge?
- Is your eye itchy or painful?
- Do you use contact lenses?
- What eye drops do you use?
- Do you have a history of auto-immune diseases or glaucoma?
Alarm symptoms that should prompt urgent evaluation include:
- Severe headaches with nausea
- Significant light sensitivity
- Severe foreign body sensation that prevents you from keeping your eye open
- Pupils not changing in size when a light is shined on it (the black center should get smaller when exposed to light)
Treatment for the Various Types of Pink Eye
Antibiotic eye drops are routinely prescribed to patients with bacterial conjunctivitis. Patients can choose between ointments and drops.
Ointment vs Drops
- Ointment (bacitracin vs Bacitracin-polymyxin B) is best for children or those who have difficulty with drops.
- Drops (Erythromycin vs Trimethoprim polymyxin B) may cause 30 minutes of blurry vision following administration, so they should be avoided by adults who have to read, drive, or perform tasks that require clear vision immediately after dosing.
Viral conjunctivitis will go away on its own and doesn’t require antibiotics. Ask your doctor to make sure you don’t have allergic conjunctivitis and miss out on effective therapy for this diagnosis (see below).
There are numerous therapies available for allergic conjunctivitis, including topical eye drops: Naphazoline-Pheniramine, Ketotifen, and Olopatadine, just to name a few. These are the most common and effective options. Be careful that you don’t inadvertently develop toxic conjunctivitis from a preservative in one of the aforementioned eye drops.
The treatment for toxic conjunctivitis is as simple as discontinuing the use of the agent. Your first step should be to stop using topical agents that aren’t absolutely necessary. Under no circumstance, however, should you stop using eye drops for glaucoma without first discussing it with your ophthalmologist or primary care physician. Make sure all your over-the-counter topical drops are preservative-free.
Keep in mind that it can take up to four weeks after discontinued use of an offending agent for the redness to clear up. Some eye drops cause a brief rebound redness when you stop taking them. This will go away, but it might temporarily look worse. If this is the case, ask your doctor to make sure this is what’s happening. Otherwise, wait it out until the redness goes away.