This 67YO female has a known history of Plaquenil toxicity. Her bilateral 20/200 vision and macular findings have been stable since discontinuing this medication 30 years ago.
Triton color imaging and swept-source OCT show classic findings for severe hydroxychloroquine toxicity, including an oval area of foveal pigment loss and outer retinal atrophy.
Most patients will have preserved central foveal pigment giving a bulls-eye appearance, although our patient has loss of outer retina and RPE throughout. Interestingly, choroidal en face imaging shows bilateral dilated choroidal pachyvessels.
On fundus autofluorescence (FAF), the central maculas are hypo-FAF, although an atypical hyper-FAF ring extends around each optic nerve.
Learning Points:
Current screening guidelines should make Plaquenil toxicity, as found in our patient, a thing of the past. Last revised in 2016, the American Academy of Ophthalmology (AAO) recommends that a baseline exam be performed before starting the medication, with annual screenings beginning at least 5 years after initiating treatment, unless major risk factors are present. However, in practice, patients are usually screened yearly once they are placed on this medication.
Optical coherence tomography (OCT) is performed annually to assess outer retinal findings, including ellipsoid zone loss. Humphrey 10-2 visual field testing (24-2 for Asians, since their macular involvement is usually more peripheral) is also needed annually, as about 10% of patients will have field loss despite normal examinations and OCT testing.
Plaquenil dosing should also be based on real, not ideal, weight to better predict the optimal dose. See Marmor et al Ophthalmology 2016;123:1386-1394 for the full screening guidelines.
