A white 49-year-old woman was referred to our office complaining of visual distortion in her right eye present for 2 weeks. Her past medical history included severe Sjogren's syndrome and she was on multiple medications, none of which she brought with her. Her symptoms were loss of central vision and overall blurred vision with visual acuity of 20/25 in the right eye and 20/30 in the left eye; her pupils were normal. Her optometrist and referring ophthalmologist found no abnormalities.

Our initial exam included fundus photography, fluorescein angiography (FA), blue laser fundus autofluoresence (FAF), and spectral-domain optical coherence tomography (SD-OCT) using both the Cirrus HD-OCT system (Carl Zeiss Meditec, Jena, Germany) and SPECTRALIS SD-OCT (Heidelberg Engineering, Heidelberg, Germany).

The fundus photo showed no abnormality and her FA and FAF also appeared normal. The Cirrus shows blunting in the foveal reflex but does not confirm a diagnosis (Figure 1). The SPECTRALIS SD-OCT image shows a “flying saucer” elliptical shape with disruption of the photoreceptors at the inner segment/outer segment junction (Figure 2). On en face SD-OCT an early bull's eye is apparent, suggesting hydroxychloroquine toxicity (Figure 3).

DIAGNOSIS
We learned that this patient had been taking hydroxychloroquine sulfate 200 mg (Plaquenil, Sanofi-Aventis) for 8 years. A 10-2 visual field test with the Humphrey Visual Field Analyzer (Carl Zeiss Meditec) confirmed a toxicity to hydroxychloroquine. In this case, SPECTRALIS SD-OCT provided early detection of hydroxychloroquine toxicity, before any visual acuity loss had occurred.

David M. Brown, MD, is the Director of the Greater Houston Retina Research Center and practices at Retina Consultants of Houston and The Methodist Hospital in Houston, TX. He is on the Retina Today Editorial Board. Dr. Brown can be reached via e-mail at dmbmd@houstonretina.com.