Treatment and Clinical Course
The current standard of care for herpetic dendrites in the United States includes topical trifluridine 1% every 2 hours and topical cycloplegia if an anterior chamber reaction is present. Application of trifluridine 1% is not to exceed 9 times/day and is not to be used for more than 21 days. This restriction is related to the mechanism of the drug. Trifluridine 1% targets thymidine kinase using a nonselective mechanism and causes corneal toxicity by affecting both healthy cells and virus-infected cells. It also includes thimerosal as a preservative.
Recently, topical ganciclovir 0.15% became available in the United States. The gel preparation has been available for more than 10 years in Europe and is well tested. This medication offers a convenient dosing regimen as a topical treatment. Ganciclovir's mechanism of action uniquely targets virus-infected cells, decreasing the viral load while sparing normal corneal cells and reducing corneal toxicity.[1,2] Topical ganciclovir 0.15% penetrates the corneal stroma and reaches therapeutic levels in the aqueous humor.
Some practitioners embrace the use of oral preparations alone for treating herpes simplex keratitis epithelial disease, citing favorable compliance and decreased ocular surface toxicity. It has been reported in the literature that oral medications reach therapeutic levels in tears. It is unclear whether these medications work by reducing the viral load in the ciliary ganglion or by reducing viral replication.
The patient in this casewas treated with ganciclovir 0.15%gel in the left eye 5 times/day. Instructions on proper instillation of the gel and known side effects were discussed with the patient. A follow-up appointment was scheduled for the next day to reassess corneal findings. After 5 days of treatment, the dendrite was completely healed and the ganciclovir gel was tapered to 3 times/day for 1 week. Figures 3 and 4 show the resolution of the herpetic dendrite after treatment.
Figure 3. Resolved dendritic lesion under white light. A ghost dendrite is observable.
Figure 4. Resolved lesion with sodium fluorescein dye under cobalt blue filter.
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Cite this: Alissa M. Coyne. A 48-Year-Old Man With Tearing and Photophobia - Medscape - Jul 25, 2013.