CASE 4 The answer is A: anterior uveitis.
Uveitis is often associated with systemic disease or infection, and diagnosis is typically suspected based on a history of conditions such as sarcoidosis, juvenile idiopathic arthritis, Kawasaki’s disease, Sjögren’s syndrome, toxoplasmosis, human immunodeficiency virus (HIV), tuberculosis (TB), syphilis, herpes simplex, and herpes zoster.26
Signs and symptoms
Signs and symptoms vary depending on the part of the uveal tract that’s involved. Anterior uveitis, or iritis, is associated with pain, photophobia, redness, and a varying degree of vision loss. Posterior and intermediate uveitis are less likely to be associated with pain, but can be accompanied by decreased visual acuity and floaters.27
Physical findings
Visual acuity in patients with uveitis can range from normal to varying degrees of vision loss. Redness around the iris can be seen; conjunctival infection is most marked around the circumference of the corneal limbus rather than more peripherally, as seen in conjunctivitis. On slit lamp examination, the beam of light can be seen in the aqueous humor due to protein and leukocyte accumulation—a phenomenon known as “flare.” The pupillary light reflex may be abnormal, and the pupillary opening may be irregular rather than round due to anterior and posterior synechia.28
Management
Patients should be referred to an ophthalmologist for management of the immediate condition and to prevent or treat complications such as vision loss, optic nerve damage, and glaucoma. Acute management includes topical steroids, such as prednisolone acetate ophthalmic 1% 2 to 4 times daily, as well as treatment of the underlying condition. Long-term management varies, depending on the cause of the uveitis.26,29
If the etiology is unknown, a workup should be considered to identify inflammatory and infectious disorders that might be causing uveitis. Chest radiograph is a good beginning to look for evidence of sarcoidosis or TB; serologic testing for syphilis, HIV, and lupus may also be considered.26,29
CASE 5 The answer is D: Provide an urgent referral to an ophthalmologist.
This patient has viral keratitis caused by herpes. While the pain and foreign body sensation are the same for bacterial and viral keratitis, herpesvirus is distinguishable by the branching opacity that develops on the cornea.
Varicella zoster is the most common cause of viral keratitis, although it can also be caused by herpes simplex and adeno-virus. Because a person who is infected with herpes has the virus for life, however, multiple attacks are possible. Reactivation is associated with stress and a weakened immune system, but may occur spontaneously, as well. Patients who wear contact lenses are no more likely than those who don’t to be infected with the herpesvirus.
Bacterial keratitis is often associated with contact lenses, particularly when they’re continually worn, but also with normal wear.30 Immunosuppression, dry ocular surfaces, and topical corticosteroid use may predispose patients to bacterial keratitis, as well.12 Staphylococcus aureus, Pseudomonas aeruginosa, coagulase-negative Staphylococcus, diphtheroids, and Streptococcus pneumoniae are the most common pathogens.31
Signs and symptoms
Patients with keratitis typically complain of eye pain, a sensation of having a foreign body in the eye, photophobia, tearing, and vision changes; a mucopurulent discharge is sometimes present, as well.3 The condition is easily distinguished from conjunctivitis, which typically does not involve eye pain or vision changes.
Physical findings
Visual acuity may be affected if the lesion or corneal edema involves the visual axis. Physical exam in a patient with bacterial keratitis sometimes shows a gray or white corneal opacity, along with corneal erythema. As already noted, a penlight exam will reveal a branching opacity in patients with herpes keratitis.30
Management
Patients with keratitis should be referred immediately to an ophthalmologist32 for a slit lamp evaluation, treatment, and close follow-up.
Corneal cultures can be difficult to obtain, but before prescribing antibiotics, an attempt to collect samples should be made. This can be done—after the administration of topical anesthesia—with a sterile calcium alginate swab. Gently swab the cornea and then inoculate the appropriate gels or mediums. Avoid contact with lashes and eyelids to prevent culture contamination.32
When herpesvirus is suspected, start the patient on an antiviral agent such as trifluridine ophthalmic (1%) 9 times a day, vidarabine ophthalmic (3%) 5 times daily, or 400 mg oral acyclovir 5 times a day. Patients with bacterial keratitis should be started on antibiotic eye drops with Pseudomonas coverage, such as ofloxacin (0.3%), ciprofloxacin (0.3%), or tobramycin (0.3%), 6 to 8 times a day.9
CORRESPONDENCE Uyen Michelle Le, MD, 967 Galindo Court, Milpitas, CA 95035; mlkala21@aol.com