PP8 CLINICAL AUDIT OF VISUAL ACUITY AND ISHIHARA TEST PERFORMED ON NEWLY DIAGNOSED TUBERCULOSIS PATIENTS BEFORE INITIATION OF ETHAMBUTOL TREATMENT

Xiao Rou Tan, Ying Quan Kok, Jia Hui Chong, Jun Cong Low, Chee Yik Chang

Medical Department, Hospital Sultanah Aminah, Johor Bahru, Malaysia

Introduction
Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a significant public health challenge in Malaysia, which is currently classified as having an intermediate TB burden. Ethambutol, a first-line anti-TB drug, is associated with ethambutol-induced optic neuropathy (EON), a potentially irreversible adverse effect that can result in permanent vision loss. Therefore, baseline and periodic visual assessments, such as visual acuity and colour vision tests, are recommended during ethambutol therapy.

Methods
An initial clinical audit was conducted in the isolation ward of Hospital Sultanah Aminah Johor Bahru (HSAJB) from March 1 to April 30, 2024. This involved a retrospective review of case notes for patients newly diagnosed with active TB who were started on ethambutol. A re-audit was carried out from February 1 to March 30, 2025, using the same inclusion and exclusion criteria.

Results
In the initial audit, only 1 out of 20 patients (5%) had a documented baseline visual assessment. To improve this, a Continuous Medical Education (CME) session was conducted in July 2024. Targeted interventions started since January 2025, with implementation of a visual assessment checklist stamp and the placement of Snellen and Ishihara charts in the ward. In the re-audit, compliance improved significantly to 14 out of 25 patients (56%).

Conclusion
This audit demonstrated a substantial improvement in the performance of baseline visual assessments during ethambutol. Nonetheless, the overall compliance rate remains suboptimal. Continued efforts-including the development of structured protocols, regular staff training, and institutional support are crucial to ensure consistent adherence to visual screening practices and enhance patient safety.