(See also Introduction to Corneal Disorders Introduction to Corneal Disorders Symptoms that suggest corneal involvement (eg, rather than simple conjunctivitis) include unilateral involvement, pain (foreign body sensation and ache—not just a gritty sensation), particularly... read more .)
Superficial punctate keratitis is a nonspecific finding. Causes may include any of the following:
Symptoms include photophobia, foreign body sensation, lacrimation, redness, and slightly decreased vision. Slit-lamp Slit-lamp examination The eye can be examined with routine equipment, including a standard ophthalmoscope; thorough examination requires special equipment and evaluation by an ophthalmologist. History includes location... read more or ophthalmoscope examination of the cornea reveals a characteristic hazy appearance with multiple punctate speckles that stain with fluorescein. With viral conjunctivitis Viral Conjunctivitis Viral conjunctivitis is a highly contagious acute conjunctival infection usually caused by an adenovirus. Symptoms include irritation, photophobia, and watery discharge. Diagnosis is clinical... read more , preauricular adenopathy is common and chemosis may occur.
Keratitis that accompanies adenovirus conjunctivitis resolves spontaneously in about 3 weeks. Blepharitis Blepharitis Blepharitis is inflammation of the eyelid margins that may be acute or chronic. Symptoms and signs include itching and burning of the eyelid margins with redness and edema. Diagnosis is by history... read more , keratoconjunctivitis sicca Keratoconjunctivitis Sicca Keratoconjunctivitis sicca is chronic, bilateral desiccation of the conjunctiva and cornea due to an inadequate tear film. Symptoms include itching, burning, irritation, and photophobia. Diagnosis... read more , and trachoma Trachoma Trachoma is a chronic conjunctivitis caused by Chlamydia trachomatis and is characterized by progressive exacerbations and remissions. It is the leading cause of preventable blindness worldwide... read more require specific therapy. When caused by overwearing contact lenses, keratitis is treated with discontinuation of the contact lens and an antibiotic ointment (eg, ciprofloxacin 0.3% four times a day), but the eye is not patched because serious infection may result. Contact lens wearers with superficial punctate keratitis should be examined the next day. Suspected causative topical drugs (active ingredient or preservative) should be stopped.
Ultraviolet (UV) B light (wavelength < 300 nm) can burn the cornea, causing keratitis or keratoconjunctivitis. Arc welding is a common cause; even a brief, unprotected glance at a welding arc may result in a burn. Other causes include high-voltage electric sparks, artificial sun lamps, and sunlight reflected off snow at high altitudes. UV radiation increases 4 to 6% for every 1000-ft (305-m) increase in altitude above sea level, and snow reflects 85% of UVB.
Symptoms are usually not apparent for 8 to 12 hours after exposure and last 24 to 48 hours. Patients have lacrimation, pain, redness, swollen eyelids, photophobia, headache, foreign body sensation, and decreased vision. Permanent vision loss is very rare.
Diagnosis is by history, presence of superficial punctate keratitis, and absence of a foreign body or infection.
Treatment consists of an antibiotic ointment (eg, bacitracin or gentamicin 0.3% ointment every 8 hours) and occasionally a short-acting cycloplegic drug (eg, cyclopentolate 1% drop every 4 hours). Severe pain may require systemic analgesics (eg, acetaminophen 500 mg every 4 hours for 24 hours). The corneal surface regenerates spontaneously in 24 to 48 hours. The eye should be rechecked in 24 hours. Dark glasses or welder’s helmets that block UV light are preventive.