Hydroxychloroquine (HCQ) retinopathy could result in severe and irreversible vision loss without prompt intervention. With so much at stake, optometrists cannot afford to underestimate the importance of screening and early detection.

 Researchers recently reported on early optical coherence tomography (OCT) abnormalities due to HCQ toxicity that may develop through normal visual field (VF) testing. They found that patients with high-risk HCQ exposure and normal VF testing may develop subtle but characteristic OCT abnormalities.

The team evaluated 10 patients with HCQ-associated OCT abnormalities and normal VF testing, analyzed OCT findings and performed ancillary tests such as color fundus photography, fundus autofluorescence, multifocal electroretinography and microperimetry. 

Seventeen of the 20 total eyes illustrated OCT abnormalities and normal VF testing. These OCT alterations included attenuation of the parafoveal ellipsoid zone and loss of a clear continuous inter-digitation zone. Several eyes went as far as progressing to advanced parafoveal outer retinal disruption and/or paracentral visual field defects.

These findings indicate that “structural alterations may precede functional impairment,” according to the study. Thus, the researchers conclude it is “important to employ a screening approach that includes OCT to assess for these early findings. Ancillary testing should be considered in cases with suspicious OCT changes and normal VFs.”

Garrity ST, Jung JY, Zambrowski O, et al. Early hydroxychloroquine retinopathy: optical coherence tomography abnormalities preceding Humphrey visual field defects. Br J Ophthalmol. February 28, 2019. [Epub ahead of print].