Antimalarial-induced maculopathy: accuracy of Amsler grid as a diagnostic tool and risk factors

Abstract

Objective: To determine the sensitivity, specificity, and agreement of Amsler grid (AG) in detecting antimalarial induced maculopathy (AM) compared to combination of dilated ocular examination and Humphrey visual field (HVF) 10-2 and to estimate the risk factors of AM.

Material and method: 20 patients with AM and 20 patients with no AM were included between October 1, 2010 and June 30, 2011 in Siriraj Hospital, Thailand. Sensitivity, specificity and unweighted kappa were used to determine accuracy of AG. Logistic regression was used to explore risk factors associated with AM.

Results: The sensitivity and specificity of AG were 40% and 100%, respectively. The agreement of AG and HVF 10-2 was poor with kappa of 0.4. Creatinine clearance < 60 ml/min/1.73 m2 and bilateral macular abnormality were associated with AM at the same odds ratio of 8.9 (95% confidence interval: 1.3 to 61.2).

Conclusion: AG may be used as an additional test between ocular evaluation visits providing the availability and low cost. Patients with renal impairment and bilateral macular abnormality are associated with AM.