Short Term Fluctuation in 10-2 Visual Field Testing for Hydroxychloroquine Retinopathy
This 75 year old woman with systemic lupus erythematosus takes hydroxychloroquine 400 mg/day and has done so for 19 years. She is 5 feet 3.5 inches tall and weighs 155 pounds. The daily dosing is at the borderline of 6.5 mg/kg/day and the duration places her in a higher risk group for hydroxychloroquine retinopathy. Serial 10-2 visual field testing is not straightfoward, as there is considerable short term fluctuation in local thresholds. For example, compare the red circled locations at the three dates of testing. On 7/9/2009, the thresholds of two adjacent points were elevated, but on 3/10/2011 and 3/12/2012, the thresholds for these same points were not elevated. Similar comments apply to the blue circled and green circled locations. This variability makes interpretation of the visual fields difficult. A case such as this is ideal for use of a more objective test, such as multifocal electroretinography or spectral domain optical coherence tomography.