ABNORMALITIES OF THE EYE STRUCTURES
Pupils and iris
Coloboma of iris
Often autosomal dominant
Defect of lid, iris, lens, retina, or choroid
Always inferior—keyhole appearance of iris; in lid, manifests as cleft
Possible CHARGE association
Leucokoria—white reflex
Retinoblastoma
Cataract
Retinopathy of prematurity
Retinal detachment
Larval granulomatosis
Lens
Cataracts—lens opacities; the most important congenital etiologies:
Prematurity (many disappear in a few weeks)
Inherited—most autosomal dominant
Congenital infection—TORCH (especially rubella); also, measles, polio, influenza, varicella, vaccinia
Galactosemia
Chromosomal (trisomies, deletions and duplications, XO)
Drugs, toxins, and trauma (steroids, contusions, penetrations)
Ectopia lentis—instability or displacement of lens; edge of displaced lens may be visible in pupillary aperture
Differential:
Trauma—most common
Uveitis, congenital glaucoma, cataract, aniridia, tumor
Systemic causes
} Marfan syndrome (most with superior and temporal; bilateral)
} Homocystinuria—inferior and nasal
} Ehlers-Danlos
Ocular muscles
Strabismus
Definition—Misalignment of the eyes from abnormal innervation of muscles
Diagnosis—Hirschberg corneal light reflex—most rapid and easily performed;
light reflex should be symmetric and slightly nasal to center of each pupil
Patch the good eye to eliminate amblyopia, the eye muscle surgery
Pseudostrabismus
Epicanthal folds and broad nasal bridge
Caused by unique facial characteristics of infant
Transient pseudostrabismus; common up to age 4 months
Conjunctiva
A 12-hour-old newborn is noted to have bilateral conjunctival injection, tearing, and some swelling of the left eyelid. Physical examination is otherwise normal.
Ophthalmia neonatorum
Redness, chemosis, edema of eyelids, purulent discharge
Causes:
Chemical conjunctivitis most common in first 24 hours of life
From silver nitrate and erythromycin
- gonorrhea—2–5-day incubation; may be delayed >5 days due to suppression from prophylactic eye treatment
} Mild inflammatory and serosanguineous discharge, then thick and purulent
} Complications—corneal ulceration, perforation, iridocyclitis
- trachomatis—5–14-day incubation; most common
} Mild inflammation to severe swelling with purulent discharge
} Mainly tarsal conjunctivae; cornea rarely affected
Diagnosis—Gram stain, culture, PCR (polymerase chain reaction) for chlamydia
Treatment:
- gonorrhea: ceftriaxone ´ 1 dose IM + saline irrigation until clear
Chlamydia: erythromycin PO ´ 2 weeks + saline irrigation until clear (may prevent subsequent pneumonia)
The red eye
Bacterial conjunctivitis
General conjunctival hyperemia, edema, mucopurulent exudate (crusting of lids together), and eye discomfort
Unilateral or bilateral
- pneumonia, H. influenza (non-typable), S. aureus, other strep
Treatment—warm compresses and topical antibiotics
Viral conjunctivitis
Watery discharge, bilateral, usually with URI
Adenovirus, enterovirus
Epidemic keratoconjunctivitis = adenovirus type 8
Good hand-washing
Allergic
Chemical
Household cleaning substances, sprays, smoke, smog
Extensive tissue damage, loss of sight
Keratitis—corneal involvement
- simplex, adenovirus, S. pneumoniae, S. aureus, pseudomonas, chemicals
Foreign bodies → corneal abrasion (pain, photophobia)
Anterior uveitis = iridocyclitis (from ciliary body to iris)
Periorbital versus orbital cellulitis (see below)
Dacryocystitis (S. aureus, H. influenza, S. pneumoniae), dacroadenitis (S. aureus, streptococci, CMV [cytomegalovirus], measles, EBV [Epstein-Barr virus], trauma)
Treatment—underlying cause and topical steroids
Retina and vitreous
Retinopathy of prematurity (ROP)
Prematurity, hyperoxia, and general illness
From mild to severe progressive vasoproliferative scarring and blinding retinal detachment
Treatment—cryosurgery or laser photocoagulation
Retinoblastoma
Most common primary malignant intraocular tumor
Recessive-suppressive gene—13q14 → family members need to be screened
Average age of diagnosis = 15 months for bilateral and 25 months for unilateral
Rarely discovered at birth
Initial sign in most = leucokoria
Appears as white mass
Second most common—strabismus
Diagnosis—CT scan to confirm; no biopsy (spreads easily)
Need to consider enucleation—radiation, chemotherapy, laser therapy, cryotherapy
Prognosis poor if extends into orbit or optic nerve
EYE INJURIES
Corneal abrasions
Symptoms—pain, tearing, photophobia, decreased vision
Diagnosis—first anesthetize eye, then fluorescein and blue-filtered light (Wood’s lamp)
Treatment—pain relief and topical antibiotics
Foreign body
Topical anesthetic and irrigation to remove
If embedded, send to ophthalmologist
PERIORBITAL VERSUS ORBITAL CELLULITIS
Periorbital cellulitis
Inflammation of lids and periorbital tissue without signs of true orbital involvement; insidious onset; low-grade fever; no toxicity
Causes—trauma, infected wound, abscess of lid, sinusitis, bacteremia (H. influenza
nontypable, S. pneumoniae, S. aureus)
May be first sign of sinusitis that may progress to orbital cellulitis
Physical exam: inflammation with intact eye movements; normal vision; no proptosis
Diagnosis—clinical (blood culture unlikely to be positive)
Treatment—oral or IV (depending on severity) antibiotics (cover for S. aureus and gram positive resistant strains)
Orbital cellulitis
A 7-year-old boy presents with swelling around the eye 2 days after suffering an insect bite to the eyelid. There is edema, erythema, and proptosis of the eye. Marked limitation of eye movements are noted. He has a low-grade fever.
Infection of orbital tissue including subperiosteal and retrobulbar abscesses
Physical examination
Ophthalmoplegia (eyeball does not move)
Chemosis
Inflammation
Proptosis
Toxicity, fever, leukocytosis, acute onset
Causes: paranasal sinusitis, direct infection from wound, bacteremia
Organisms nontypable H. influenza, S. aureus, beta hemolytic strep, S. pneumoniae, anaerobes
Diagnosis—CT scan with contrast of orbits and surrounding area (best initial test)
Treatment—Intravenous antibiotics (again, cover for S. aureus) and may require sinus and/or orbital drainage (will give you culture and sensitivities) if no improvement