Optical Coherence Tomography Minimum Intensity as an Objective Measure for the Detection of Hydroxychloroquine Toxicity

• Published in: Investigative ophthalmology & visual science 2018-04, Vol.59 (5), p.1953-1963
• Main Authors: Allahdina, Ali M, Stetson, Paul F, Vitale, Susan, Wong, Wai T, Chew, Emily Y, Ferris, III, Fredrick L, Sieving, Paul A, Cukras, Catherine
• Format: Article
• Language: English
• Subjects: Adult; Aged; Antirheumatic Agents - toxicity; Case-Control Studies; Electroretinography; Female; Humans; Hydroxychloroquine - toxicity; Male; Middle Aged; Prospective Studies; Retina; Retina - drug effects; Retinal Diseases - chemically induced; Retinal Diseases - diagnostic imaging; Rheumatic Diseases - drug therapy; Sensitivity and Specificity; Tomography, Optical Coherence - methods; Visual Acuity - drug effects; Visual Fields - drug effects
• ISSN: 1552-5783; 0146-0404; 1552-5783
• DOI: 10.1167/iovs.17-22668

As optical coherence tomography (OCT) minimum intensity (MI) analysis provides a quantitative assessment of changes in the outer nuclear layer (ONL), we evaluated the ability of OCT-MI analysis to detect hydroxychloroquine toxicity. Fifty-seven predominantly female participants (91.2% female; mean age, 55.7 ± 10.4 years; mean time on hydroxychloroquine, 15.0 ± 7.5 years) were enrolled in a case-control study and categorized into affected (i.e., with toxicity, n = 19) and unaffected (n = 38) groups using objective multifocal electroretinographic (mfERG) criteria. Spectral-domain OCT scans of the macula were analyzed and OCT-MI values quantitated for each subfield of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid. A two-sample U-test and a cross-validation approach were used to assess the sensitivity and specificity of toxicity detection according to OCT-MI criteria. The medians of the OCT-MI values in all nine of the ETDRS subfields were significantly elevated in the affected group relative to the unaffected group (P < 0.005 for all comparisons), with the largest difference found for the inner inferior subfield (P < 0.0001). The receiver operating characteristic analysis of median MI values of the inner inferior subfields showed high sensitivity and high specificity in the detection of toxicity with area under the curve = 0.99. Retinal changes secondary to hydroxychloroquine toxicity result in increased OCT reflectivity in the ONL that can be detected and quantitated using OCT-MI analysis. Analysis of OCT-MI values demonstrates high sensitivity and specificity for detecting the presence of hydroxychloroquine toxicity in this cohort and may contribute additionally to current screening practices.