Plaquenil Maculopathy

Plaquenil Maculopathy
SYMPTOMS Typically asymptomatic in the early stages of the disease but eventually may experience central vision loss and central scotomas
SIGNS Typically bilateral
Initially starts off as granular pigment alterations which will eventually turn into a ring of RPE and photoreceptor atrophy in the parafovea and perifovea region (fovea will typically be spared at first but will eventually be involved as well)
If patient is of Asian descent, RPE and photoreceptor changes may also be noted in other areas of the posterior pole and along the vascular arcades
WORK-UP Full eye exam with dilated retinal exam, Visual field threshold 10-2 (defects present as paracentral scotomas at first but will eventually turn into a ring scotoma with relative sparing of the fovea), Visual field threshold 24-2 or 30-2 if patient is of Asian descent, OCT analysis of the macula (a widefield scan should be done in patients of Asian descent), Fluorescein Angiography, Fundus Autofluorescence, Fundus photos, Infrared retinal imaging, Watzke-Allen test, Macular photostress test, Color vision, Electrodiagnostic testing (multifocal ERG), Amsler grid
TREATMENT Give take home Amsler grid in order to monitor for change
If there is no evidence of plaquenil maculopathy, patient needs to be monitored
If there is evidence of plaquenil maculopathy, the dosage of Plaquenil needs to be lowered or the Plaquenil needs to be completely discontinued (discussion with patient's primary care provider is imperative before lowering dosage of Plaquenil or completely discontinuing Plaquenil)
FOLLOW-UP Baseline testing should be done on all patients taking Plaquenil within the first year
If testing shows no evidence of plaquenil maculopathy and there are no risk factors associated with developing plaquenil maculopathy, the patient should next be seen back in 5 years. After taking Plaquenil for 5 years, the patient should be seen back every year
If testing shows no evidence of plaquenil maculopathy but there are risk factors associated with developing plaquenil maculopathy, the patient should be seen back every year
If testing shows possible evidence of plaquenil maculopathy, the patient should be seen back in 2-4 months (closer to 2 months if there are risk factors associated with developing plaquenil maculopathy)
If testing shows definitive evidence of plaquenil maculopathy, the patient should be seen back in 2-4 months once the dosage of Plaquenil is lowered or the Plaquenil is completely discontinued (closer to 2 months if there are risk factors associated with developing plaquenil maculopathy and/or the dosage of Plaquenil is lowered)
ADDITIONAL LAB | TESTS None
ETIOLOGY Plaquenil has an affinity for the RPE and thus tends to build up in the RPE. This may eventually cause disruption of RPE metabolism and phagocytic activity which leads to a build-up of old photoreceptor outer segments. Subsequently, there will be RPE and photoreceptor damage and loss
DIFFERENTIAL DX Geographic atrophy, Cone dystrophy, Stargardt disease
NOTES Typical dosing of Plaquenil is 200mg BID
Risk factors for developing plaquenil maculopathy include the following: Taking Plaquenil > 5.0mg/kg of real weight per day* (if a patient is taking the typical dosage of Plaquenil that is 200mg bid per day, the threshold weight is 175 pounds), Taking Plaquenil for greater than 5 years*, Renal disease with a low eGFR* (will cause impaired clearance of Plaquenil which will increase toxicity of the drug), Concurrently using Tamoxifen* (increases toxicity of Plaquenil by 5x), The presence of other types of macular disease* (such as age-related macular degeneration), Taking a cumulative dose of Plaquenil that is greater than 1000g, Patient is more than 60 years old (aging changes to RPE will make the RPE more susceptible to toxicity and damage from Plaquenil use), Liver Disease, Obesity. (Risk factors that are marked with a * are the most significant)
If the patient is taking Plaquenil at the typical dosage and there are no risk factors associated with developing plaquenil maculopathy, the chances of getting maculopathy is less than 1% within 5 years, less than 2% within 10 years, and greater than 20% if using for more than 20 years
There is an increased chance of stopping or even reversing plaquenil maculopathy if caught early enough
Toxicity to the macula from Plaquenil can last months to years even after discontinuing the drug (in fact, the toxicity effects of Plaquenil can last up to 3 years due to slow clearance from the body)
Plaquenil Maculopathy: OCT of the macula demonstrating loss of the ellipsoid zone in the parafoveal and perifoveal region. This is also called "Turtle sign" or "Flying saucer sign" https://www.retinalphysician.com/issues/2015/nov-dec/hydroxychloroquine-maculopathy-an-update-on-scree
Posted in Macula, Ocular Conditions