The risk of hydroxychloroquine retinopathy and the role of the multifocal electroretinogram in screening and monitoring retinal toxicity

• Author / Creator

  Beatrice Adamptey

• Background: Hydroxychloroquine sulfate (Plaquenil) is a useful, inexpensive drug with a high systemic safety profile. Prolonged use of Plaquenil however causes toxic effects on ocular structures, including the retina. The aim of this study was to determine the role of the multifocal electroretinogram (mfERG) in screening and monitoring Plaquenil retinal toxicity by determining its sensitivity and specificity, assessing the changes in abnormal mfERG due to Plaquenil retinal toxicity after therapy cessation and identifying risk factors associated with Plaquenil retinal toxicity. Methods: 414 patients on Plaquenil therapy were retrospectively studied. Multifocal ERG, spectral domain-OCT and 10-2 Humphrey visual field chart images were reviewed. Clinical and demographic characteristics of the patients were also collected. COX univariate and multivariate regression analyses were used to determine risk. Relative sensitivity and specificity of mfERG, SD-0CT and 10-2 Humphrey visual field were determined using logistic regression and ROC curve analysis. One way-ANOVA with repeated measure and Post Hoc analysis was applied to assess change in abnormal mfERG response secondary to Plaquenil therapy cessation.
  Results: The most significant predictors of Plaquenil toxicity were cumulative dose >1 kg (cumulative dose >1 kg, odd ratio (OR)= 0.21, 95% CI= 0.047-0.957, cumulative dose >2 kg, OR= 0.33, 95% CI= 0.127-0.875) , daily drug dose >5 mg/kg (OR= 0.19, 95% CI= 0.072-0.506) and duration of therapy >5 years (OR= 2.30, 95%C1= 0.06-0.30, P=0.028). mfERG, SD-OCT and 10-2 VFT share a commonality in their ability to correctly classify non-toxic patients (specificity >90%) but mfERG was the most sensitive of the three (sensitivity= 92%).
  Conclusion: A combination of at least two of these screening tests yields higher sensitivity and specificity. Abnormal mfERG response in Plaquenil retinal toxicity could be recovered if therapy is discontinued before significant reduction in mfERG ring amplitudes (not >50%) occurs.

• Subjects / Keywords

  • Hydroxychloroquine sulfate
  • multifocal electroretinogram
  • cessation
  • sensitivity
  • specificty
  • risk of toxicity

• Graduation date

  Fall 2018

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3BC3TC93

• License

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