RECOMMENDATIONS - Revised recommendations on screening for chloroquine and hydroxychloroquine retinopathy

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Ophthalmology. 2011 Feb;118(2):415-22.

Revised recommendations on screening for chloroquine and

hydroxychloroquine retinopathy.

Marmor MF, Kellner U, Lai TY, Lyons JS, Mieler WF; American Academy of

Ophthalmology.

Eye Institute at Stanford, Stanford University, Palo Alto, California.

Abstract

BACKGROUND: The American Academy of Ophthalmology recommendations for

screening of chloroquine (CQ) and hydroxychloroquine (HCQ) retinopathy

were published in 2002, but improved screening tools and new knowledge

about the prevalence of toxicity have appeared in the ensuing years.

No treatment exists as yet for this disorder, so it is imperative that

patients and their physicians be aware of the best practices for

minimizing toxic damage.

RISK OF TOXICITY: New data have shown that the risk of toxicity

increases sharply toward 1% after 5 to 7 years of use, or a cumulative

dose of 1000 g, of HCQ. The risk increases further with continued use

of the drug. DOSAGE: The prior recommendation emphasized dosing by

weight. However, most patients are routinely given 400 mg of HCQ daily

(or 250 mg CQ). This dose is now considered acceptable, except for

individuals of short stature, for whom the dose should be determined

on the basis of ideal body weight to avoid overdosage.

SCREENING SCHEDULE: A baseline examination is advised for patients

starting these drugs to serve as a reference point and to rule out

maculopathy, which might be a contraindication to their use. Annual

screening should begin after 5 years (or sooner if there are unusual

risk factors).

SCREENING TESTS: Newer objective tests, such as multifocal

electroretinogram (mfERG), spectral domain optical coherence

tomography (SD-OCT), and fundus autofluorescence (FAF), can be more

sensitive than visual fields. It is now recommended that along with

10-2 automated fields, at least one of these procedures be used for

routine screening where available. When fields are performed

independently, even the most subtle 10-2 field changes should be taken

seriously and are an indication for evaluation by objective testing.

Because mfERG testing is an objective test that evaluates function, it

may be used in place of visual fields. Amsler grid testing is no

longer recommended. Fundus examinations are advised for documentation,

but visible bull's-eye maculopathy is a late change, and the goal of

screening is to recognize toxicity at an earlier stage.

COUNSELING: Patients should be aware of the risk of toxicity and the

rationale for screening (to detect early changes and minimize visual

loss, not necessarily to prevent it). The drugs should be stopped if

possible when toxicity is recognized or strongly suspected, but this

is a decision to be made in conjunction with patients and their

medical physicians.

PMID: 21292109

http://www.ncbi.nlm.nih.gov/pubmed/21292109

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