Retinal Toxicity Screening - An ounce of prevention is worth a pound of cure
Welcome to #ChatJRheum November edition
This month’s article examines the risks of hydroxychloroquine (HQC) and retinal toxicity
among Korean patients on longstanding HCQ for treatment of RA or SLE. Among the 123
participants, 17 patients (13.8%) had evidence of retinal toxicity. Among those patients with
retinal toxicity, the mean daily HCQ dose was 7.2mg/kg and mean duration of HCQ use was
15.2 years. The results of the study confirmed higher mean daily dose and longer duration of
HCQ as being significant risk factors for development of retinal toxicity. Presence of kidney
disease and hypertension were additional risk factors.
What I found most interesting, and worth highlighting, was their Table 2 data on distribution
according to HCQ dose per weight. It showed only 1 patient with retinal toxicity on HCQ dose
below 5mg/kg. This particular patient took HCQ 4.9mg/kg for 18.1 years. There were no
patients with retinal toxicity who took HCQ for <5 years.
There results correspond very nicely to the recent American Academy of Ophthalmology
recommendations on screening for chloroquine (CQ) and hydroxychloroquine (HCQ)
retinopathy.1 Their recommendations are a maximum daily HCQ use of 5.0 mg/kg (based on
real weight). At recommended doses, their data indicate the risk of toxicity is under 1% in
those treated up to 5 years, but this risk rises significantly to 20% after 20 years. Based on
this data, their recommendation are for a baseline exam to rule out preexisting maculopathy,
and for annual screening to begin “after 5 years for patients on acceptable doses and without
major risk factors”. These major factors include concomitant renal disease, or use of
tamoxifen.
This article had me recalculating HCQ doses in my patients this week, and also reflecting on my current practice for HCQ screening, which is to recommend annual screening in all my patients. So I ask you, colleagues, what is your current practice for HCQ screening? Would you would
change your recommendations based on the above data?
Your thoughts and comments are welcome, and I hope you will join in the discussion.
- Sarah Troster, Forum Moderator
1 Marmor, M. F et al. American Academy of Ophthalmology Statement: Recommendations on Screening for Chloroquine and Hydroxychloroquine Retinopathy (2016 Revision) Ophthalmology. 123(6):1386-1394. https://doi.org/10.1016/j.ophtha.2016.01.058
