Quick Reference: Screening for Chloroquine & Hydroxychloroquine (Plaquenil) Retinopathy

by Huda Minhas, OD and Ryan Corte, OD
Dec 16, 2020
3 min read
🔥7.4k views

This guide has been updated for 2020 and provides a quick reference guide based on the AAO's updated screening guidelines for chloroquine and hydroxychloroquine (Plaquenil) retinopathy.

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As optometrists, it is important that we are aware of the possible ocular complications that can occur from the use of high risk medications. Patients starting chloroquine (CQ) or hydroxychloroquine (HCQ; i.e. Plaquenil) should have a baseline examination that serves as a reference point, as well as to rule out any preexisting maculopathies.

While most rheumatologists are now routinely prescribing their patients 400 mg of HCQ (or 250 mg CQ) daily for the management of conditions like systemic lupus erythematosus and rheumatoid arthritis, individuals of short stature often have their dosage determined off of their ideal body weight to avoid overdosing.

Annual screening should begin after 5 years of medication use, unless the patient has risk factors which warrants earlier screening.

Daily Dose and Duration of Use

Early literature suggested that cumulative dosage was indicative of risk factor. However, a more accurate assessment is based on duration AND daily dose/weight factor. The most critical risk factor in the development of HCQ toxicity is excessive daily dose by <5.0 mg/kg weight. There’s no new data for CQ, but older literature suggests using <2.5 mg/kg weight.

Racial Differences in Pattern of Retinopathy

We’ve always learned that toxic damage occurs parafoveal (bull’s eye pattern). But, in Asian patients, there’s a pericentral pattern of damage. This requires an adjustment in screening methods as explained below.

Review:

  • Parafoveal - retinal changes 2-6 degrees from the fovea
  • Pericentral - retinal changes >8 degrees from the fovea

Risk of Toxicity

Dependent on daily dose and duration of use. The risk of toxicity for the first 5 years is <1%, and up to 10 years is <2%. The risk increases to 20% after 20 years, and 4% for every subsequent year.

Other Risk Factors

Major risk factors are high dose, duration of use, renal impairment, tamoxifen use, and macular disease.

Screening for Chloroquine & Hydroxychloroquine (Plaquenil) Retinopathy

  • Eye Examination:
    • Baseline: Complete ocular health examination including a dilated retinal assessment. Fundus examination within one year. May consider baseline VF and OCT (especially if abnormalities are present).
    • Annual Screening: May be started after 5 years of use, or sooner if presence of major risk factors
  • Visual field
    • Non-Asian patients: 10-2
    • Asian patients: 24-2 or 30-2
  • One (or more) of the following tests:
    • OCT of the Macula
      • Concern: Parafoveal thinning of photoreceptor layers and/or loss of the inner-segment/outer-segment junction
      • Concern in Asian patients: extra-macular pattern of disease with abnormalities beyond the visual arcades. Wide-field OCT may be necessary.
    • Multifocal ERG
      • Concern: Decreased parafoveal waveform amplitudes (may need to extend to 20 degrees eccentricity in Asian patients)
    • Fundus autofluorescence
      • Concern: Parafoveal hyperfluorescence (widefield observation may be required for Asian patients to detect extramacular disease)

It's critical to educate your patients on the risk of toxicity and the importance of screening. If early changes and/or visual loss is detected, consult with your patient's prescribing doctor immediately, as they should discontinue the medication and consider alternative therapies.

References:

  1. Marmor MF, Kellner U, Lai TY, Melles RB, Mieler WF; American Academy of Ophthalmology. Recommendations on Screening for Chloroquine and Hydroxychloroquine Retinopathy (2016 Revision). Ophthalmology. 2016 Jun;123(6):1386-94. doi: 10.1016/j.ophtha.2016.01.058. Epub 2016 Mar 16. PMID: 26992838.
  2. “Recommendations on Screening for Chloroquine and Hydroxychloroquine Retinopathy - 2016.” American Academy of Ophthalmology, 20 May 2016, www.aao.org/clinical-statement/revised-recommendations-on-screening-chloroquine-h.
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About Huda Minhas, OD

Huda Minhas, OD is originally from Toronto, Canada. She completed her undergrad at the University of Toronto, and went on to pursue a bilingual Doctorate of Optometry program at the Inter-American University of Puerto Rico. She currently resides in Sacramento, California. Huda's clinical interests are in primary eye care, ocular disease, and pre-post operative management of surgical patients. She is currently part of a vibrant OD/MD group practice. In her spare time, she is passionate about weightlifting, hiking, traveling, and enjoying fine cuisine. 

About Ryan Corte, OD

Ryan Corte attended The Ohio State University College of Optometry and graduated in 2012. He completed an Optometric Residency in Primary Care and Ocular Disease at the Illinois College of Optometry in 2013. He currently splits time between Modern Eye Care and Premier Family Eye Care in metropolitan Charlotte, NC. Ryan is a former Executive President of the American Optometric Student Association. He also serves on the Student and New Graduate Committee of the American Optometric Association.


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