Leflunomide and Ocular Adverse Effects: Risk Awareness and Clinical Guidance

General Understanding of Leflunomide and Ocular Safety

Post-marketing surveillance has reported ocular events such as conjunctivitis, blurred vision, and keratitis in patients taking leflunomide. However, these events are generally mild, reversible, and infrequent. Pivotal clinical trials showed no significant difference in ocular adverse event rates compared to placebo. There is currently no conclusive evidence linking leflunomide to permanent or severe ocular damage.

Common Ocular Symptoms

Patients may experience conjunctival injection, foreign body sensation, lacrimation, or transient visual blurring. These symptoms usually appear within weeks to months after starting therapy and are often self-limiting or responsive to symptomatic treatment. Persistent vision loss, ocular pain, or photophobia should prompt immediate drug interruption and ophthalmology referral.

Corneal Deposits and Ulceration – Rare Reports

Isolated case reports describe corneal deposits or ulceration in long-term users, but causality remains unestablished. Patients with pre-existing corneal pathology require enhanced ophthalmic surveillance. If corneal deposits are detected, a thorough assessment of drug attribution is warranted.

Comparison with Other DMARDs

Leflunomide carries a significantly lower ocular risk than hydroxychloroquine, which mandates regular visual field and OCT screening due to its irreversible retinal toxicity. Leflunomide does not require routine ophthalmologic monitoring; eye examinations are reserved for symptomatic individuals.

Monitoring Recommendations During Treatment

For patients without baseline ocular disease, no routine eye check is needed. Any new eye discomfort, visual change, or persistent redness warrants timely ophthalmologic evaluation. For those with pre-existing fundus disorders or glaucoma, a baseline eye exam before starting leflunomide and periodic follow-up thereafter is advisable.

Management Upon Ocular Symptoms

When ocular symptoms arise, first consult a rheumatologist to assess drug association. Mild symptoms allow continued therapy with symptomatic relief. Persistent or worsening symptoms necessitate drug hold and ophthalmology workup. If confirmed as drug-related, switching to an alternative DMARD should be considered.

Patient Education and Self-Monitoring

Patients should be educated about red-flag visual symptoms: blurred vision, diplopia, eye pain, or constant tearing. They should proactively report ocular status at each visit. For long-term therapy, an annual routine eye examination can provide objective safety reassurance.