CLINICAL CHALLENGES
Trust No One
When taking a referral case, start from square one and make your own diagnosis. You may end up with a different answer and solution.
Eric Schmidt, O.D.

Sometimes patients present with a self diagnosis or they come in from someone else's office while being treated for an ocular condition. But just because another doctor initiated therapy for a condition he diagnosed doesn't necessarily mean that his diagnosis or treatment is correct. Here's an example of what I mean.

Tracing the red eye's origin

A mother brought in her 7-year-old daughter, L.T., and said that L.T. woke up with a red eye about two weeks ago that had stayed red since. The mother reported that when the condition first presented, it was "fire red" nasally only and that a mild amount of discharge was present.

She took L.T. to the pediatrician, who prescribed sulfaceta-mide 10% for "pink eye." A physician's assistant told L.T.'s mother to administer the drops five times each day in L.T.'s right eye. After one week of treatment, L.T.'s eye still hadn't improved.

After a return visit to the pediatrician L.T. received a prescription for gentamicin drops to administer q.i.d. OD and oral amoxicillin. The pediatrician said that L.T. had an upper respiratory infection and that it was probably causing the red eye. She also told L.T.'s mother to take L.T. to see an eye doctor if her eye didn't clear up in five days.

Now, 16 days after the initial presentation, L.T. was in my office. Her mother related the history to me and said that if anything, the eye was a little worse. L.T.'s eye remained red in the nasal aspect of the conjunctiva. When she woke up in the morning, she had a small amount of discharge and the eye felt a little irritated. After a day in school, her eye felt worse, which L.T. described as an ache.

L.T. saw no discharge throughout the day and the redness didn't change as the day progressed. When I asked L.T. about her vision she said it seemed "fine." L.T. had no other episodes of red or infectious eyes and was generally healthy. She took no medications chronically nor was she currently taking any medications other than the aforementioned antibiotics.

Performing the exam

L.T.'s visual acuity (VA) measured 20/30- OD, 20/30 OS. Through a pinhole occluder, her VA improved to 20/25+ OU. Cover/uncover test revealed no tropia or phoria and extraocular muscles showed no restrictions. Her pupils measured 6 mm and were equal and responsive to light with no afferent defect.

L.T. passed her color vision test and her random dot stereo test was perfect at 40". A refraction of -0.50 sphere OD and -0.75 -0.50 x 180 OS improved the VA to 20/20 in each eye. The slit lamp exam of her OD revealed that her lids weren't edematous and there was no lid debris or meibomian gland inspissation.

L.T.'s nasal bulbar conjunctiva exhibited a sectoral area of injection that originated at the limbus and proceeded in a wedge shape to the peripheral conjunctiva. I graded this focal injection as 2+. The temporal bulbar conjunctiva was not injected at all. Her inferior palpebral conjunctiva showed 2+ large papillae, but there were just trace papillae on the superior palpebral conjunctiva.

At her limbus, running from 4:00 counterclockwise to 10:00 were seven raised, whitish-opaque nodules. These nodules didn't have any blood vessels around their base and they didn't stain with either sodium fluorescein (NaFl) or Rose Bengal. The peripheral cornea OD, however, did stain with NaFl in a thin band vertically from about 2:00 to 4:00. The anterior chamber was deep and quiet with no cell or flare visible. The slit lamp exam of L.T.'s OS was normal with the exception of trace papillae on her upper and lower palpebral conjunctiva.

Targeting the usual suspects

L.T.'s case was far from your typical childhood red eye. Close inspection of the exam data shows marked differences from "regular" conjunctivitis.

First, L.T.'s case is unilateral. Second, it's asymmetrical affecting the OD sectorally. This case is also recalcitrant to topical antibiotic therapy (even though the antibiotics prescribed for her aren't the standard of care anymore). The papillae that were present were also not typical. They were larger than average and present far more in the OD than OS. The fifth finding that sets this case apart is the limbal nodules, which aren't normally associated with viral or bacterial conjunctivitis.

The causes of a unilateral red eye that's recalcitrant to treatment and accompanied by limbal nodules in a child are few. The differential diagnosis includes pingueculitis, vernal catarrh, epidemic keratoconjunctivitis, corneal ulcer, Staph marginal ulcer or atypical herpes simplex keratitis. In this case, however, the limbal nodules are the key to the diagnosis.

Not your typical bumps

The whitish bumps at L.T.'s limbus are phlyctens, thus making the diagnosis phlyctenular keratoconjunctivitis. Phlyctens arise from an inflammatory response to some irritant or antigen. The phlyctens, or phlyctenulae, are accumulations of lymphoid tissue and have a proclivity for the corneal limbus. In some cases the phlyctens migrate into the cornea, producing a more severe form of keratoconjunctivitis. The focal disruption along with the inflammation that is associated with the phlyctenulae cause the symptoms of irritation, lacrimation, photophobia and mild discharge.

Phlyctenular keratoconjunctivitis is known to have some inciting factors. It's clear that the condition is a delayed hypersensitivity reaction to some foreign proteins. The tuberculin protein has been identified as a major cause of phlyctenulosis. Up until 20 years ago, it was recommend-ed that any patient who had a diagnosis of phlyctenular keratoconjunctivitis receive a purified protein derivative (PPD) test for tuberculosis (TB).

However, with the wane in the prevalence of TB, the more likely etiology of phlyctenulosis is now Staph hypersensitivity. The condition is more common in children and young adults. It occurs more often in spring and summer than in autumn or winter. The phlyctens and the resultant inflammation are manifestations of an antigen/antibody response to the Staph toxins. Although, as in this case, the condition may mimic a classic allergy response, it isn't produced by allergens responsible for atopic conditions.

Ridding the red eye

Treatment for phlyctenular keratoconjunctivitis ranges from artificial tears to topical antibiotics and steroids. L.T. had a rather severe case based on the corneal involvement. This, and the fact that it had been hanging around for two weeks, compelled me to prescribe Tobradex drops q.i.d. for her OD. I also suggested that the mother employ lid scrubs b.i.d. to control the Staph debris. I dictated a letter that was sent to her pediatrician as well.

I re-examined L.T. one week later and the eye was much improved. There was one small phlycten remaining, but the corneal staining and conjunctival inflammation was resolved. Because there was one phlycten still present, I asked that L.T. continue the Tobradex q.i.d. for one more week. She was to continue with the lid scrub regimen every evening. She hasn't had any recurrences in the past year and now sees 20/20 with her new glasses.

Make your own diagnosis

Obviously, as this case proves, it's hard to correctly diagnose a red eye without performing a slit lamp exam. Don't just blindly accept another practitioner's diagnosis -- take an in-depth look and use all of your skills to give your patient the proper treatment.

L.T.'s case also highlights the absurdity that allows other medical practitioners to prescribe eye drops unregulated even though they don't use the proper diagnostic equipment to make an accurate diagnosis.

Contributing Editor Eric Schmidt, O.D., is director of the Bladen Eye Center in Elizabethtown, N.C. E-mail him at KENZIEKATE@aol.