Abstract
Purpose :
To analyze a single center’s experience with optical coherence tomography angiography (OCTA) in hydroxychloroquine (HCQ) toxicity
Methods :
Prospective single-center cross-sectional study of 16 patients (32 eyes) with past or current HCQ use. Patients with concurrent retinal pathology were excluded. Patients without known HCQ toxicity were placed into groups based on their cumulative HCQ dosage (<720 g into Group 1, 721g-1440 g into Group 2, >1440 g into Group 3), and patients with known HCQ toxicity were placed into Group 4. Patients were screened with 10-2 Humphrey Visual Field (HVF), Spectral-Domain Optical Coherence Tomography (SD-OCT), Fundus Autofluorescence (FAF), and OCTA (RTVue-XR Avanti; Optovue, Fremont, California, USA). OCTA images with blink artifacts or fixation errors were excluded. Testing was reviewed for presence of paracentral HVF defects, IS/OS attenuation, and hypo or hyperautofluorescence on FAF. Additionally, quantitative analysis on OCTA imaging was performed to determine superficial and deep capillary densities in the overall 3x3 mm scan area.
Results :
Of the 32 eyes screened during the study, there were 12 eyes in Group 1, 6 in Group 2, 8 in Group 3, and 6 in Group 4. Eyes in Group 4 demonstrated signs of advanced HCQ toxicity on 10-2 HVF, SD-OCT, and FAF. Among eyes in Groups 1-3, isolated HVF abnormalities were found in 4/12 in Group 1 (33%), 1/6 in Group 2 (16.7%), and 2/8 in Group 3 (25%). One eye in Group 1 had isolated FAF changes.
No eyes were found to have parafoveal nonperfusion on OCTA. Average superficial capillary density was 51.3% (± .067) and average deep capillary density was 42.8% (± .074). Average superficial capillary densities did not vary between eyes with known HCQ toxicity and those without known HCQ toxicity (54.5% vs 50.6% respectively, p=0.229). However, average deep capillary densities varied between eyes with known HCQ toxicity and those without known HCQ toxicity (48.9% vs 41.4% respectively, p=0.02), with a weak trend towards increasing deep capillary density with increasing cumulative HCQ dosage (R=0.235, p=0.89).
Conclusions :
OCTA demonstrates increased deep capillary vascular density in eyes with known HCQ toxicity compared to those without known HCQ toxicity. However, confounding factors such as age and segmentation errors can account for these changes, and so further studies are needed to determine if OCTA remains a valid test for HCQ screening.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.