Ocular Disorders: Trichiasis and Trachoma

Trichiasis

• Misdirection of eyelashes towards the globe, different from entropion
• Causes include: aging, congenital, scarring of posterior lid lamella, blepharitis, epiblepharon, herpes zoster, trachoma, ocular cicatricial pemphigoid, Stevens-Johnson syndrome, vernal keratoconjunctivitis, chemical burns
• Signs include conjunctival injection, pain, foreign body sensation, tear film abnormalities, posterior lamellar scarring, involutional entropian, punctate epitheliopathy, microbial keratitis, scarring
• Management involves epilation (lash removal), addressing underlying conditions (e.g., taping the eyelid, therapeutic contact lenses, or ocular lubricants)

Trachoma

• Caused by Chlamydia trachomatis infection, endemic in Africa, Middle East, and Asia
• Incubation period is 5-12 days
• Initially conjunctivitis, progressing to scarring of tarsal conjunctiva, entropion and trichiasis
• Leading cause of preventable blindness
• Causes eye ulcers, further scarring, and vision loss

Entropian

• Inversion of the eyelid margin inward towards the globe
• Types include involutional, cicatrical, and spastic
• Involutional: age-related, typically lower lid, affecting more women, smaller tarsal plates, lax lids, often resolves spontaneously
• Cicatrical: scarring, often from trauma, burns, infections, or medication, leads to lid margin being pulled inward
• Spastic: involuntary muscle contractions, less common, causes irritation, inflammation or trauma
• Congenital: rare, results from improper development of lower eyelid retractor insertion, eyelid instability

Symptoms of Eyelid Disorders

• Redness
• Irritation
• Eye discomfort and pain (from eyelashes rubbing against the cornea/conjunctiva)
• Corneal and/or conjunctival epithelial disturbance by lashes
• Conjunctival hyperemia (redness of the conjunctiva)
• Corneal exposure
• Tearing
• Mucous discharge

Pre-septal Cellulitis

• Common infection of eyelid and periorbital soft tissue, primarily in children
• Common causes are Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus, Anaerobes, bacterial infection of upper respiratory tract.
• Signs and symptoms include acute pain, swollen eyelids, redness, blurred vision, conjunctivitis, and tearing.
• May be preceded by upper respiratory tract infections, such as sinusitis.
• Differential diagnosis should include insect bites, allergic conjunctivitis, trauma, contact dermatitis, hordeolum.

Bacterial Orbital Cellulitis

• Infection of tissues behind the septum
• Commonly spreads from adjacent sinuses, such as the ethmoid sinus
• Possible causes include Haemophilus influenzae, Staphylococcus aureus, Streptococcus pneumoniae, Beta-hemolytic streptococci
• More severe than pre-septal cellulitis
• Progresses rapidly, may compress optic nerve
• Symptoms include pain with eye movement, chemosis (swelling of conjunctiva), proptosis (eye bulging), ophthalmoplegia (eye muscle paralysis), restricted EOM's (extraocular movements), reduced vision

Management of Eyelid Disorders

• Confirmation of diagnosis
• Treatment of underlying conditions (e.g., addressing pre-disposing conditions like upper respiratory tract infections, diabetes, or other medical conditions)
• Appropriate use of antibiotics (IV in more severe cases)
• Considering CT scans for no improvement following antibiotics.

Tumors (Basal Cell Carcinoma, Squamous Cell Carcinoma)

• Basal cell carcinoma: most frequent eyelid malignancy (80-90% of all eyelid cancers); slow growing, destructive, locally invasive, pearly borders, ulcerative center
• Squamous cell carcinoma: aggressive, 2nd most common (5%), elderly, fair-skinned individuals, more aggressive than BCC
• Management includes surgical removal, skin grafting where needed, cryotherapy, radiation therapy. Early diagnosis is crucial for successful outcomes.

Benign Eyelid Lesions

• Cysts of Zeis, cysts of moll
• Molluscum contagiosum: contagious skin lesion, usually presents as small, dome shaped, waxy nodules
• Thyroid eye disease: most common in middle-aged women; symptoms include proptosis, lid retraction, lid lag, irritation due to corneal dryness, lid edema, conjunctival chemosis, and possible optic nerve compression (rare)

This quiz explores two significant ocular disorders: trichiasis and trachoma. Learn about their causes, signs, and management options. Test your understanding of how these conditions affect eye health and contribute to vision impairment.