Purchase this article with an account.
Katherine Elizabeth Talcott, Atsuro Uchida, Ming Hu, Obinna Ugwuegbu, Sunil K Srivastava, Rishi P Singh, Stephanie Kaiser, Natalia Albuquerque Lucena Figueiredo, Alison Rogozinski, Thuy Le, Leina Lunasco, Jamie L. Reese, Justis P Ehlers; Long-Term Longitudinal Ellipsoid Zone Mapping on Spectral Domain OCT in Eyes with Hydroxychloroquine Use to Evaluate for Subclinical Outer Retinal Alterations: A Possible Early Marker for Toxicity. Invest. Ophthalmol. Vis. Sci. 2019;60(9):1854. doi: https://doi.org/.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Loss of ellipsoid zone (EZ) integrity on optical coherence tomography (OCT) is a hallmark feature of hydroxychloroquine (HCQ) toxicity but early alterations can be subtle. The purpose of this study is to evaluate longitudinal changes on OCT that may precede clinical HCQ toxicity using a semi-automated EZ mapping platform.
This study was an IRB-approved retrospective image analysis of patients currently taking HCQ who had OCTs at two time points. Patients with concurrent macular disease were excluded. The two macular cube scans were exported and analyzed in the EZ mapping platform. Seven outer retinal parameters were utilized to evaluate for subtle alterations over time: mean parafoveal (central 2-mm) ONL-EZ thickness/volume, mean parafoveal EZ-RPE thickness/volume, en face percentage of EZ total attenuation (EZ thickness = 0μm), en face EZ attenuation (EZ thickness < 20μm). Outputs were compared between scans using paired t-tests.
Four hundred one eyes of 401 subjects were included. Mean age was 57.6±0.2 years, mean daily HCQ dose was 367.1±72.6 mg, and mean HCQ dose based on actual body weight was 4.9±1.8 mg/kg. At time of the first OCT, mean duration of HCQ use was 5.8±3.9 years and cumulative HCQ dose was 2.1±1.5 grams. Mean time between the two OCT time points was 3.1±0.9 years. There was a significant increase in en face EZ attenuation from the first OCT (1.4±5.6%) to the second OCT (1.8±6.3%; p=0.01). The increase in EZ loss significantly correlated with age (p=0.04), drug duration (p=0.004), and cumulative dose (p=0.002), but not daily dose (p=0.24) or dose based on actual body weight (p=0.11). There was also an increase in en face EZ total attenuation between the 2 OCTs (0.9±5.0% vs 1.1±5.3%) but this was non-significant (p=0.08). There was no significant longitudinal change in mean parafoveal (central 2-mm) ONL-EZ thickness/volumes or EZ-RPE thickness/volumes (all p>0.09).
Longitudinal assessment of outer retinal integrity revealed a significant increase in EZ attenuation which correlated with age, cumulative dose, and duration on drug. Additional research is needed to further validate these subclinical progressive changes and their impact on identification of HCQ toxicity.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
This PDF is available to Subscribers Only