Conjunctival Diseases
The conjunctiva is the first line of ocular defence, making conjunctival disease one of the most frequent presentations in primary eye care. Red eye, discharge, irritation, and chemosis are hallmarks of conjunctival pathology — ranging from self-limiting infections to vision-threatening neoplasia. This section covers infectious, allergic, degenerative, and neoplastic conjunctival conditions with fast access to clinically focused summaries.
Last updated: March 2026
Conjunctival conditions often present with overlapping features: injection, discharge, papillae, follicles, or subconjunctival changes. Key clinical differentiators include discharge character (purulent vs. watery vs. mucoid), laterality, itch, pain, lymphadenopathy, and corneal involvement. Contact lens wear, atopic history, sexual history, and immunocompromised status are important risk modifiers. Urgent referral is required for suspected neoplasia, severe allergic disease with corneal involvement, or any features of scleritis.
Conjunctival disease index (A–Z)
Bacterial Conjunctivitis
Mucopurulent discharge with diffuse conjunctival injection; usually unilateral at onset and self-limiting, though topical antibiotics shorten duration.
View conditionViral Conjunctivitis
Watery discharge, follicular response, and preauricular lymphadenopathy; EKC produces subepithelial infiltrates and is highly contagious.
View conditionAllergic Conjunctivitis
Bilateral itch, chemosis, and papillary reaction driven by IgE-mediated mast cell degranulation; managed with antihistamines and mast cell stabilisers.
View conditionVernal Keratoconjunctivitis
Severe atopic disease in young males; cobblestone papillae and limbal Horner-Trantas dots are pathognomonic, with corneal shield ulcers as a sight-threatening complication.
View conditionAtopic Keratoconjunctivitis
Chronic bilateral disease in adults with atopic dermatitis; lid eczema, fornix scarring, and corneal neovascularisation carry risk of permanent visual loss.
View conditionGiant Papillary Conjunctivitis
Mechanical irritation from contact lenses or prostheses produces large upper tarsal papillae with mucus and lens intolerance; responds to lens holiday.
View conditionChlamydial Conjunctivitis
Chronic follicular conjunctivitis with superior pannus from Chlamydia trachomatis; trachoma remains the leading infectious cause of preventable blindness worldwide.
View conditionEpiscleritis
Sectoral or diffuse episcleral redness that blanches with phenylephrine; usually benign and self-limiting, but systemic associations should be excluded.
View conditionScleritis
Deep boring pain with violaceous injection that does not blanch; associated with systemic autoimmune disease and requires urgent referral to exclude necrotising disease.
View conditionPinguecula
Yellowish interpalpebral elastotic degeneration of the bulbar conjunctiva; usually asymptomatic but may become inflamed, warranting UV protection and lubricants.
View conditionPterygium
UV-related fibrovascular ingrowth from the nasal limbus onto the cornea; Stocker's iron line marks the leading edge, with surgery indicated for visual axis encroachment.
View conditionConjunctival Nevus
Benign melanocytic lesion with characteristic intralesional cysts; serial photodocumentation is essential to detect the rare malignant transformation to conjunctival melanoma.
View conditionOcular Surface Squamous Neoplasia
Spectrum from intraepithelial neoplasia to invasive SCC presenting as a gelatinous limbal mass; UV exposure and HPV are risk factors requiring prompt biopsy and referral.
View conditionConjunctival Lymphoma
Salmon-pink subconjunctival mass typically representing extranodal marginal zone B-cell lymphoma; systemic staging is mandatory and treatment includes local radiotherapy.
View conditionSubconjunctival Hemorrhage
Sharply demarcated bright-red extravasation beneath the bulbar conjunctiva; usually benign and spontaneous, resolving in 1–3 weeks without treatment.
View conditionRed Flags — When to Refer Urgently
Most conjunctival conditions can be managed in primary eye care, but the following features warrant same-day or urgent ophthalmology referral:
- Reduced visual acuity not explained by discharge or surface irregularity alone
- Severe deep ocular pain or pain unrelieved by topical anaesthetic (suggests scleritis or keratitis)
- Ciliary flush with photophobia — raises concern for anterior uveitis or corneal involvement
- Corneal shield ulcer or significant epithelial defect in VKC — sight-threatening complication
- Suspected OSSN or conjunctival lymphoma — any unexplained limbal or subconjunctival mass
- PAM with atypia or rapidly changing pigmented conjunctival lesion
- Gonococcal conjunctivitis — hyperacute purulent discharge, risk of corneal perforation within hours
- Neonatal conjunctivitis (ophthalmia neonatorum) — any discharge in a newborn requires urgent assessment
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