Red Eye

We commonly think of “Red Eye” as a main symptom, whereas we’ d be less likely to miss serious eye disease if we thought instead of “Painful Eye” vs. Red Eye without real pain.

To skim through the clinician’s thought-process, scroll through first the non-serious causes, looking for clues like types of discharge, etc. Then we’ll discuss the serious causes. For more in-depth discussion & explanations, see Red Eye — Full Text. See also Diagrams — Eye Anatomy.

Causes of Red Eye(s)

xxxxxxxxNo Eye Pain	xxxxxxxxPainful  !!!
• Viral Conjunctivitis (“pink-eye”) • Bacterial Conjunctivitis • Herpes Conjunctivitis • Allergies (Airborne & Contact allergies) • STD Causes (Gonorrhea, Chlamydia) • Foreign Body on Conjunctiva • Episcleritis • Pterygium (inflamed) • Subconjunctival Hemorrhage x	• Corneal Abrasion / Foreign Body • Corneal Ulcer / Keratitis • Scleritis • Iritis / Uveitis • Optic Neuritis (eye often not red) • Acute Closed-Angle Glaucoma • Corneal Abrasion (recurrent) • Contact Lens Wearer xxxxxxSee also Diagrams — Eye Anatomy

Painful Red Eye  =  Very Serious !!!

• True Eye Pain!  Worse than a scratchy, gritty, itchy, irritating sensation like “something-stuck-in-eye”
• Except for the Corneal Abrasion, we send all other truly painful red eyes to an ER which has an ophthalmologist on-call, or to an ophthalmologist if same-day appointment available

New Vision Changes (measured formally) → urgent ophthalmology evaluation

• Be sure apparent vision deficit is real, by Pinholing

RED EYE(S)  —   WITHOUT TRUE EYE PAIN

Thin, Watery Discharge:  Most likely Viral or Allergic Conjunctivitis

1.  Symptoms present under 3 weeks, No other diagnosis below likely

            >>  Viral Conjunctivitis

2.  Both Eyes Red, PLUS any of following:

• Other Hay Fever symptoms (runny nose, sneezing); OR
• Symptoms present over 3 weeks; OR
• Frequent recurrent bouts

            >> Allergic Conjunctivitis

3.  History of recent eye-drop use; OR Lots of eye cosmetics

            >> Contact Allergy

4.  Follicles inside lining of lower lid; Symptoms present several wks (esp. if recent genital STD)

            >> Chlamydia Conjunctivitis [picture in link]

5.  Groups of blisters on an eyelid.  Only one eye involved.

            >> Herpes simplex Conjunctivitis

6.  One-sided red eye, and Foreign Body noted (may need to look under upper lid)

            >> Foreign Body on Conjunctiva

6a. If symptom of Foreign Body began where people were cutting or hammering steel

            >> refer to an Ophthalmologist (see link Foreign Body)

7.  Local Redness, only the eye, & NOT the inside lining of lower lid.  Often NO tearing or discharge

            >> Episcleritis  [picture in link]

Thick Discharge

1.  Profuse discharge, wipe it away & more recurs within minutes (white / yellow / green):

            >> Bacterial Conjunctivitis

2.  Discharge horrible, covers the entire eye (esp. if genital STD symptoms)’; Swelling of conjunctiva

            >> maybe Gonorrhea [picture in link].  Send to ER (may need IV antibiotics)

No Discharge

1.  Localized Redness in just one part of eye, with NO redness inside lining of lower eyelid

• Episcleritis (tufts of blood vessels noted, slight itchy sensation)  [picture in link]
• Subconjunctival Hemorrhage (no abnormal sensation; just blood, no vessels) [picture in link]
• Inflamed Pterygium (typical location between iris & bridge of nose)  [picture in link]

2.  Conjunctiva Red, both over eye(s) & also lining of the eyelid(s)

• Usually an itchy sensation
• Symptoms less than 3 weeks, and no other diagnosis above likely

            >> Viral Conjunctivitis

TRULY PAINFUL RED EYE

1. Vomiting, Severe Eye Pain, Cloudy Cornea

            >> Acute Closed-Angle Glaucoma:  send straight to ER for surgery

2. Spot on Cornea (might only see by staining)

            >> Keratitis:   send right to ophthalmologist, via ER if specialist available

3. Severe pain, worse with eye movement

• Bluish hue to sclera
• Tender eyeball (by gently wiggling it through the closed eyelid)

            >> Scleritis:  send right to ophthalmologist, via ER if specialist available

4. Non-reactive pupil (usually tiny) &/Or Pain in red eye when light shined in other eye

            >> Iritis:  Call ophthalmologist

5. Abnormal pupils by Swinging Flashlight Test (see Afferent Pupillary Defect)

• Pain maybe worse with eye movement.
• Eye may not look red.

            >> Optic Neuritis:  Call ophthalmologist

6. Contact Lens Wearer with new eye pain →  Beware early Corneal Ulcer

• If lens has been out for a day, & still painful, send right to ophthalmologist, via ER if specialist available
• If lens recently out, and pain getting worse, won’t let up, send right to ophthalmologist, via ER if specialist available
• If spot noted on cornea, send right to ophthalmologist, via ER if specialist available
• If lens still in, question sanity. Remove lens ASAP !!!

7. Same-day trauma, and fluorescein staining shows a Corneal Abrasion

• If pain in eye when light shined in other (non-painful) eye: send right to ophthalmologist, via ER if ophthalmologist available
• If a topical anesthetic didn’t relieve the pain for a few minutes, the injury is also deeper than the cornea:  send right to ophthalmologist, via ER if specialist available there
• If neither of above (temporary pain relief obtained by topical anesthetic):
  • No Eye Patch (studies show it delays healing)
  • Pain medicine (even narcotics) for 1 day
  • If not all better in 24 hours, send right to ophthalmologist (this is rare)

See also Red Eye — Full Text for more in-depth explanations and discussions.