This document discusses the differential diagnosis and approach to evaluating red eye. It begins by listing conjunctivitis, scleritis, ocular foreign body, and angle closure glaucoma as possible causes of red eye. For acute onset painful red eye, common unilateral causes include corneal abrasion, foreign body, and trauma, while bilateral causes include chemical injury, contact lenses, dry eyes, and allergies. Acute painless unilateral red eye may be viral conjunctivitis or subconjunctival hemorrhage, while bilateral causes are blepharitis and allergies. Chronic red eye may result from blepharitis, dry eye, conjunctivitis, contact lenses, or thyroid eye disease.

1. Approach to Red Eye
Dr.Mohammad Dmour , M.D
Ophthalmology Department.
Islamic Hospital.

2. Pre-lecture Question
Which is/are in the differential diagnosis for red
eye?
A) Conjunctivitis
B) Scleritis
C) Ocular foreign body
D) Angle Closure Glaucoma
E) All of the Above

3. Pre-lecture Question
Which is not associated with pre- orbital/pre-
septal cellulitis?
A) Decreased visual acuity
B) Lid erythema and edema
C) Ptosis
D) Fever
E) Full ocular motility

4. Pre-lecture Question
Which of the following has no role in treating HSV
epithelial keratitis?
A) Superficial debridement
B) Topical ganciclovir (Zirgan)
C) Topical steroids
D) Oral Antivirals (acyclovir)
E) Topical trifluridine

7. Which Category Applies?
• Acute onset, painful :
1. Unilateral
2. Bilateral
• Acute onset, painless :
1. Unilateral
2. Bilateral
• Chronic
1. Unilateral
2. Bilateral

8. ACUTE ONSET, PAINFUL, UNILATERAL
• Common Causes
1. Corneal abrasion
2. Corneal foreign body (FB)
3. Subtarsal foreign body (FB)
• Less Common Causes
1. Trauma
2. Acute glaucoma
3. Uveitis
4. Corneal ulcer
5. Scleritis/episcleritis
6. Orbital cellulitis

21. ACUTE, PAINFUL, BILATERAL
1. chemical injury – alkali or acid
2. contact lens wear
3. dry eyes
4. Allergic conjunctivitis
5. dysthyroid eye disease

26. ACUTE, PAINLESS, UNILATERAL
1. Viral Conjunctivitis
2. Subconjunctival hemorrhage
3. Allergic reaction

29. ACUTE, PAINLESS, BILATERAL
1. Blepharitis
2. Allergic reactions
3. Thyroid eye disease – rare

31. CHRONIC, UNILATERAL OR BILATERAL
1. Blepharitis
2. Dry eye
3. Chronic conjunctivitis
4. Contact lens wear
5. Dysthyroid eye disease