From the Guidelines
Ganciclovir 0.15% gel used three to five times per day is the recommended topical option for preventing herpes simplex keratitis. This is based on the most recent evidence from 2024, which suggests that topical ganciclovir is less toxic to the ocular surface compared to trifluridine 1% solution 1. The use of topical antiviral treatment, in addition to oral antivirals, has been effective in preventing the progression of HSV blepharoconjunctivitis and keratitis.
Some key points to consider when using ganciclovir 0.15% gel include:
- It should be used three to five times per day for optimal effectiveness
- Oral antivirals, such as acyclovir (200 to 400 mg five times a day), valacyclovir (500 mg two or three times a day), or famciclovir (250 mg twice a day), may also be prescribed for prevention, especially in patients with frequent recurrences
- Topical corticosteroids should be avoided as they potentiate HSV epithelial infections
- Patients should have a follow-up visit within 1 week of treatment to monitor their condition and adjust treatment as needed 1.
It's also important to note that while these medications can reduce the risk of recurrence, they do not eliminate it, and patients should continue to avoid triggers like excessive UV exposure and stress. Regular ophthalmological follow-ups are essential to monitor corneal health and adjust treatment as needed.
From the FDA Drug Label
ZIRGAN ®(ganciclovir ophthalmic gel) 0. 15% is indicated for the treatment of acute herpetic keratitis (dendritic ulcers). The recommended dosing regimen for ZIRGAN is 1 drop in the affected eye 5 times per day (approximately every 3 hours while awake) until the corneal ulcer heals, and then 1 drop 3 times per day for 7 days.
Ganciclovir ophthalmic gel is used to treat herpetic keratitis, but the label does not provide information on preventing herpes simplex keratitis.
- The label only discusses treatment of the condition.
- There is no mention of prophylactic use to prevent herpes simplex keratitis. 2
From the Research
Eye Drops for Preventing Herpes Simplex Keratitis
To prevent herpes simplex keratitis, several eye drops can be used, including:
- Trifluridine 1% solution 3
- Ganciclovir 0.15% ophthalmic gel 3, 4
- Acyclovir ointment 3% 4
- Interferon alpha-2a 5
Mechanism of Action
These eye drops work by inhibiting the replication of the herpes simplex virus, thereby preventing the development of keratitis.
- Trifluridine and ganciclovir are antiviral agents that selectively target viral thymidine kinase, reducing the potential for toxicity to healthy human cells 4.
- Acyclovir is an antiviral drug that can be given topically or systemically, depending on the level of corneal involvement 6.
- Interferon alpha-2a is an immunomodulatory agent that can be used as an adjunct to antiviral therapy in cases of refractory herpes simplex keratitis 5.
Efficacy and Safety
The efficacy and safety of these eye drops have been evaluated in several clinical trials:
- Ganciclovir ophthalmic gel 0.15% has been shown to be at least as effective as acyclovir ointment for the treatment of HSV keratitis, with better tolerability 4.
- Trifluridine 1% solution and ganciclovir 0.15% ophthalmic gel have been used to treat HSV infectious epithelial keratitis, with resolution of symptoms within 3-10 days 3.
- Interferon alpha-2a has been used to treat refractory herpes simplex keratitis in an immunosuppressed patient, with quick resolution of symptoms 5.