Traumatic, iatrogenic (e.g., intraocular surgery or laser), iris neovascularization, herpes simplex or zoster iridocyclitis, blood dyscrasia or clotting disorder (e.g., hemophilia), anticoagulation, Fuchs heterochromic iridocyclitis, intraocular tumor (e.g., juvenile xanthogranuloma, retinoblastoma, angioma).

Infectious corneal ulcer, endophthalmitis, severe iridocyclitis (e.g., HLA-B27 associated, Behçet disease), reaction to an intraocular lens (sterile hypopyon), retained lens particle, device contaminant after cataract surgery (toxic anterior segment syndrome), intraocular tumor necrosis (e.g., pseudohypopyon from retinoblastoma), retained intraocular foreign body, tight contact lens, chronic corneal edema with ruptured bullae, severe inflammatory reaction from a recurrent corneal erosion, drugs (e.g., rifampin).

Compression of episcleral vessels by a gonioprism (iatrogenic), Sturge–Weber syndrome, arteriovenous fistula (e.g., carotid–cavernous sinus fistula [c-c fistula]), superior vena cava obstruction, hypotony.

Allergy, any ocular or periocular inflammation, postoperative, drugs, venous congestion (e.g., c-c fistula), angioneurotic edema, myxedema.

Vitamin A deficiency, postcicatricial conjunctivitis, Stevens–Johnson syndrome, ocular cicatricial pemphigoid, exposure (e.g., lagophthalmos, absent blink reflex, proptosis), radiation, chronic dacryoadenitis, Sjogren syndrome.

SEE 4.14, CRYSTALLINE KERATOPATHY.

Underlying uveal neoplasm, arteriovenous fistula (e.g., c-c fistula), polycythemia vera, leukemia, ophthalmic vein or cavernous sinus thrombosis, extravascular blockage of ophthalmic/orbital venous outflow.

Most Important. Multiple endocrine neoplasia type IIb (medullary carcinoma of the thyroid
gland, pheochromocytoma, mucosal neuromas; may have marfanoid habitus).

Others. Acanthamoeba keratitis, chronic keratitis, keratoconus, neurofibromatosis, Fuchs endothelial dystrophy, Refsum syndrome, trauma, congenital glaucoma, failed corneal graft, leprosy, ichthyosis, idiopathic, normal variant.

SEE 5.1, ACUTE CONJUNCTIVITIS AND 5.2, CHRONIC CONJUNCTIVITIS.

(Classic teaching is that removal of the membrane is difficult and causes bleeding). Streptococci, pneumococci, chemical burn, ligneous conjunctivitis, Corynebacterium diphtheriae, herpes simplex virus, ocular vaccinia. (Compare with “Pseudomembranous Conjunctivitis.”)

(Classic teaching is that removal of the pseudomembrane is easy without bleeding.) See earlier for causes of membranous conjunctivitis, as well as adenovirus (rarely causes true membrane formation), ocular cicatricial pemphigoid, Stevens–Johnson syndrome, superior limbic keratoconjunctivitis, gonococci, staphylococci, chlamydia in newborns, and others.

Congenital glaucoma, birth trauma (forceps injury), congenital hereditary endothelial or stromal dystrophy (bilateral), PPMD, developmental abnormality of the anterior segment (e.g., Peters anomaly), metabolic abnormalities (bilateral; e.g., mucopolysaccharidoses, mucolipidoses), interstitial keratitis, herpes simplex virus, corneal ulcer, corneal dermoid, sclerocornea.

Ocular rosacea, tight contact lens or contact lens overwear, phlyctenule, chlamydia (trachoma and inclusion conjunctivitis), superior limbic keratoconjunctivitis (micropannus only), staphylococcal hypersensitivity, vernal keratoconjunctivitis, herpes simplex or zoster virus, chemical burn, ocular cicatricial pemphigoid, aniridia, molluscum contagiosum, leprosy.

SEE 5.1, ACUTE CONJUNCTIVITIS AND 5.2, CHRONIC CONJUNCTIVITIS.

Racial melanosis (perilimbal), nevus, primary acquired melanosis, melanoma, ocular and oculodermal melanocytosis (congenital, blue-gray, not conjunctival but episcleral), Addison disease, pregnancy, radiation, jaundice, resolving subconjunctival hemorrhage, conjunctival or subconjunctival foreign body, pharmacologic (e.g., chlorpromazine, topical epinephrine), cosmetic (e.g., mascara/makeup deposits, tattoo).

Ocular cicatricial pemphigoid, Stevens–Johnson syndrome, chemical burn, trauma, drugs, long-standing conjunctival or episcleral inflammation, epidemic keratoconjunctivitis, atopic conjunctivitis, radiation, congenital, iatrogenic (postsurgical).

Amiodarone, chloroquine, Fabry disease and carrier state, phenothiazines, indomethacin.

SEE “EYELID SWELLING” in Chapter 1, Differential Diagnosis of Ocular Symptoms.

SEE 6.11, MALIGNANT TUMORS OF THE EYELID.

SEE 6.1, PTOSIS.

SEE 11.28, RETINITIS PIGMENTOSA AND INHERITED CHORIORETINAL DYSTROPHIES.

Age-related macular degeneration (ARMD), Stargardt disease or fundus flavimaculatus, albinism, cone dystrophy, rod-cone dystrophy, chloroquine or hydroxychloroquine retinopathy, adult-onset foveomacular vitelliform dystrophy, Spielmeyer–Vogt syndrome, central areolar choroidal dystrophy. SEE 11.32, CHLOROQUINE/HYDROXYCHLOROQUINE TOXICITY.

Orbital or choroidal tumor, idiopathic orbital inflammatory syndrome, thyroid eye disease, posterior scleritis, hypotony, retinal detachment, marked hyperopia, scleral laceration, papilledema, postoperative.

More Common. ARMD, ocular histoplasmosis syndrome, high myopia, idiopathic polypoidal choroidal vasculopathy, angioid streaks, choroidal rupture (trauma).