Intriguing Questions from a Corneal Patient's Treatment
BY LEO SEMES, OD, FAAO
A 67-year-old immunocompetent black female presented for retinal consultation regarding epiretinal membrane (ERM). During the course of her work-up, we discovered that she had a small corneal epithelial defect.
The lesion was <1mm in diameter, very superficial and stained with both fluorescein and lissamine green. Best-corrected visual acuity was 20/25 in each eye. Intraocular pressure was 14mmHg in each eye. There was no significant conjunctival injection, and the anterior chamber was free from cells and flare. Dilated fundus evaluation revealed minimal ERM in the right eye and mild lens changes that accounted for the slightly reduced visual acuity.
The retinal specialist advised the patient of the retinal finding and recommended that she be followed for four months, be aware of changes in vision and that she use Zymar (gatifloxacin ophthalmic solution, 0.3%; Allergan, Inc.) drops four times daily and return in one week for follow up.
An Interesting Case
There are several issues of interest in this case. First, the retinal consultation resulted in the observation recommendation based on the relatively good visual acuity.
The severity of the ERM was such that no surgical intervention was warranted.
In the face of posterior vitreous detachment, ERM may form and spontaneously resolve. This may occur in the absence of patient symptoms or decreased vision. We discovered this patent's condition at comprehensive examination.
The next area of interest is the Zymar recommendation as prophylaxis. This fourth-generation fluoroquinolone is FDA-approved for bacterial conjunctivitis caused by susceptible strains of bacteria. Literature reports support such off-label use as in this case.
The Return Visit
We saw the patient one week later. She reported using the drops as directed, but the epithelial defect had expanded. There were four distinct superficial epithelial areas of involvement. There was again staining with fluorescein and lissamine green.
At this point, we decided to discontinue the gatifloxacin and prescribe trifluridine 1% (Viroptic, Monarch Pharmaceuticals) every two hours while she was awake. We asked her to return in three days.
At the follow-up visit, the areas of corneal involvement were nearly completely re-epithelialized. We then discontinued the trifluridine and recommended non-preserved tear supplements four times per day. In one week, the cornea was completely re-epithelialized.
Examining the Treatment Plan
This case raises a number of questions. The patient presented for a retinal problem, but in the course of the comprehensive evaluation was found to have a corneal defect.
Was the Zymar wrong? Not necessarily. Fourth-generation fluoroquinolones represent excellent choices for potentially drug-resistant corneal infections. Was the dendritic lesion correctly interpreted? Perhaps not.
Was the Viroptic necessary? Support for this intervention comes from the fact that the patient responded. The initial treatment may have been the wrong course, but eventually she responded to treatment and had a successful outcome.
This case also emphasizes the importance of appropriate follow up and patient compliance. CLS
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Dr. Semes is an associate professor at the University of Alabama at Birmingham School of Optometry.