This project is designed to test the hypothesis that acyclovir is clinically useful for patients with refractory viral uveitis.

Approval of the study was obtained from the hospital's ethical committee. The study design and methodology followed the tenets of Declaration of Helsinki. All patients were provided with written informed consent and received a thorough explanation of the study design, aims, benefits and potential risks. This is a prospective non-comparative interventional study.

Aqueous humor samples were collected from participants to virus detection. Participants will take oral acyclovir 100 mg three times a day and data will be collected prospectively with regard to ophthalmologic outcomes. Study participants will be followed for up to 12 months to determine efficacy, and an additional 30 days for safety reports. Descriptive statistics will be gathered on participant demographics, uveitis characteristics, change in immunosuppressive medications, number of responders, ophthalmologic measures and change in corticosteroid dose during the study period.

Inclusion Criteria:

• Age between 18 and above.
• Chronic, vision threatening viral uveitis.
• Patients can't tolerate hormone therapy bacause of drug side effects.
• Consent to undergo anterior chamber tap and give aqueous for the study.
• Able to undergo relevant tests.
• Able to come for subsequent follow-up visits.
• Ability to provide informed consent.

Exclusion Criteria:

• Patients who are allergic to ayclovir.
• Immunocompromised patients
• Positive for HIV, Hep B and Hep C
• Not keen on participating in the study
• Patients who are incapable, either by law or mental state, of giving consents in their own right.
• Patients who are either unable or unwilling to keep scheduled appointments and adhere to the other aspects of the protocol.
• Patients who are pregnant or breastfeeding.
• Any other specified reason as determined by the clinical investigator.

The study protocol,statistical analysis plan,informed consent form and clinical study report are to be shared with other researchers.

The data will become available starting 6 months after publication.

Study protocol, statistical analysis plan and informed Consent form can be shared with other researchers. And researchers will review requests and criteria for reviewing requests.