Ophthalmology Quiz: Acanthamoeba and Glaucoma

Red Eye - Chapter 4

• A red eye is a troubling symptom, potentially indicating acute or chronic conjunctivitis
• Injection is the dilation and engorgement of blood vessels in the conjunctiva, sclera, or episclera
• Conjunctival injection is associated with conjunctival pathology (e.g., conjunctivitis).
• Ciliary injection is a more serious sign, indicating inflammation of the cornea, iris, or ciliary body.
• Acute red eye can range from easily treatable conditions (like subconjunctival hemorrhage) to serious underlying conditions needing referral.
• Conjunctivitis is inflammation of the bulbar and/or palpebral conjunctiva, often caused by bacteria, viruses, or chlamydia, or allergies (e.g., vernal keratoconjunctivitis).
• Key symptoms of conjunctivitis are inflammation and discharge.
• Classifying Conjunctivitis discharge can aid in diagnosis:
  • Purulent/mucopurulent: indicates bacterial/chlamydial infection.
  • Mucoid: suggestive of allergic disease or dry eye.
  • Watery: likely viral conjunctivitis.
• Acute bacterial conjunctivitis is caused by gram-positive (Staphylococci, Streptococcus pneumoniae, viridans) and gram-negative (Hemophilus influenzae, Neisseria gonorrhoeae, Pseudomonas aeruginosa, Moraxella) bacteria.
• Standard infection control measures are crucial when dealing with bacterial conjunctivitis due to its contagious nature.
• Treatment usually involves antibiotic eye drops or ointments.
• Systemic antibiotics are considered only exceptionally in cases like gonorrhea or chlamydia.
• Neonatal conjunctivitis (ophthalmia neonatorum) should be addressed urgently.
• Acute viral conjunctivitis is typically caused by adenoviruses. Other common viral causes include herpes simplex and herpes zoster, or acute viral illnesses.

Clinical Picture and Symptoms

• Symptoms of acute conjunctivitis can include lid edema, hyperemia, mucopurulent or purulent discharge, foreign body sensation, and possible complications.
• Spontaneous recovery is often seen within 1-2 weeks without treatment, this recovery time is shorter with treatment.
• Possible complications of acute bacterial conjunctivitis include chronic bacterial conjunctivitis (if untreated) and development of secondary keratitis with corneal ulceration.
• Viral conjunctivitis is often self-limiting.
• Acute allergic conjunctivitis involves an allergic reaction to exogenous antigens.
• Symptoms can include itching, redness, lid puffiness, and conjunctival edema.

Acute Non-Infective Conjunctivitis

• Allergic conjunctivitis is categorized as an eye inflammation due to allergic reaction to various agents (pollen, dust, mites, or medications.)

Management, Prevention, and Treatment of Different Types

• Prevention and management of conjunctivitis involve measures to prevent infection spread.
• Mild cases often resolve without treatment, but proper diagnosis is crucial.
• Systemic antibiotic use is limited to severe or complicated infections.
• Topical antibiotics are used frequently for local treatment.
• Antiviral and topical corticosteroid use can address viral and severe/allergic infections.
• General measures like avoiding touching the eyes or proper hygiene should be observed.

Corneal Ulcer and Keratitis

• Corneal ulceration involves loss of epithelium, and can range from simple abrasions to more severe ulcers involving deeper corneal layers.
• Bacterial keratitis includes infections from gram-positive and gram-negative organisms.
• The causative bacterial organisms of corneal ulceration vary widely.
• Infection control is critical, and appropriate antibiotic treatment is often necessary.

Other Types of Conjunctivitis and Related Conditions

• Phlyctenular keratoconjunctivitis is a hypersensitivity reaction in children/young adults involving the cornea and conjunctiva.
• Herpes simplex keratitis (HSV) is a common viral infection.
• A corneal ulcer may be infectious or non-infectious.
• Herpes zoster ophthalmicus results from reactivation of the varicella-zoster virus in the ophthalmic branch of the trigeminal nerve.
• Protozoal keratitis (Acanthamoeba) is a significant, serious cause of corneal damage, usually from exposure to contaminated water sources (e.g., swimming pools).
• Treatment involves vigorous topical and/or systemic anti-parasitic treatment.
• Acute angle closure glaucoma and cavernous sinus thrombosis are severe conditions requiring immediate medical attention.
• Symptoms include severe headache, pain, nausea, vomiting and various visual disturbances.
• Diagnostic investigations like MRI/MRV are necessary to confirm diagnosis.
• Treatment of infectious conditions and acute angle closure glaucoma must be managed aggressively.

Other Relevant Conditions

• Endophthalmitis is intraocular inflammation requiring urgent treatment due to potential vision loss.
• Orbital cellulitis involves inflammation of the soft tissues in the posterior orbit, commonly due to sinus infections.
• Cavernous sinus thrombosis is a rare but serious condition in which blood clots form within the cavernous sinus, frequently due to infection.
• Subconjunctival hemorrage is the collection of blood between the conjunctiva and sclera.
• Keratoconjunctivitis sicca (dry eye) is characterized by tear deficiency.
• Vernal keratoconjunctivitis (VKC) is a chronic inflammatory condition of the conjunctiva.
• Toxic conjunctivitis is caused by contact with an irritating agent.
• Episcleritis relates to inflammation of the episclera often sectoral and usually not threatening to vision.
• Scleritis is inflammation of the sclera, often accompanied by pain and may indication systemic disease.
• Photophthalmia: inflammation of cornea and conjunctiva due to exposure to intense light.