Abstract
Purpose :
Plaquenil (hydroxychloroquine, HCQ) is a highly effective drug which can cause maculopathy even after discontinuance. 2016 AAO guidelines (https://www.aao.org/clinical-statement/revised-recommendations-on-screening-chloroquine-h;) dismiss color vision testing as insensitive and non-specific. We question this assertion with new information exemplifying sensitivity of cone color testing for detecting HCQ toxicity.
Methods :
Three patients referred by retinal specialists were assessed in our Visual Neurophysiology Service (VNS) for HCQ toxicity. Testing included refraction to best VA, Humphrey (HVF) central fields (10-2 SITA-Standard), spectral domain ocular coherence tomography (SD-OCT), multifocal electroretinograms (mfERGs; ISCEV standard www.iscev.org) which provide cone and cone bipolar cell function from multiple retinal sites, fundus autofluorescence (FAF), and cone specific contrast sensitivity (CS, Innova Systems, Inc.).
Results :
An asymptomatic 71-YO HF with Rheumatoid Arthritis was taking 200mg HCQ daily for 20 years (total dose 1,460g). VA: 20/15 OD, OS, FAF: enhanced macular pigment mottling OU, HVF: parafoveal sensitivity loss, SD-OCT: inner retinal thinning OS>OD, mfERGs: reduced foveal & parafoveal >OS, CCT: borderline L cone CS, decreased M cone CS, OS>OD. A 50-YO HF with Systemic Lupus Erythematosus (SLE) took 400mg HCQ per day for 17 years (total dose 2,482g; FAF featured in: https://doi.org/10.3899/jrheum.181375). VA: 20/25 OD, OS, HVF: parafoveal scotomas OS>OD with nasal extension OS, SD-OCT: significant full-thickness macular thinning, foveal sparing OD only, FAF: Bull’s eye pattern of degeneration extending temporally OS consistent with HVF and mfERG results, CCT: significant decrease all cones, >OS. A 73-YO WF with SLE taking 200mg HCQ daily for 20 years (total dose 1,424g) reported decreased color vision for 5 years. VA: 20/30 OD, 20/40 OS, HVF: parafoveal loss OD and central loss OS, SD-OCT: diffuse foveal thinning OU, IS/OS deformities, “flying saucer” OD, FAF: Bull's eye maculopathy OS>OD, mfERGs: decreased centrally OS>OD, increased fovea/ring 2 ratio OU, CCT: severe CS loss all cone types.
Conclusions :
Cone CS can be reduced in various stages of HCQ maculopathy, and its decrease can even constitute the only presenting symptom. We advocate its use for adjunctive testing of HCQ patients and plan prospective and retrospective studies to confirm its efficacy.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.