Birdshot Chorioretinopathy: Treatment Stabilizes Vision

Norra MacReady

December 16, 2013

Visual acuity can remain stable in patients with birdshot chorioretinopathy (BSCR) for 10 years or more, a new study shows.

Best corrected visual acuity (BCVA) remained stable in patients who received short-term corticosteroid treatment and those who received longer-term treatment with corticosteroids plus an immunosuppressive agent, senior author Sue Lightman, PhD, and colleagues write in an article published online December 12 in JAMA Ophthalmology. In fact, long-term therapy was associated with a slight improvement in BCVA."As BSCR is generally considered to be a progressively deteriorating condition with a poor prognosis, this finding was very encouraging: That aggressive treatment with immunosuppression can achieve stabilization of [the patient's] condition," Dr. Lightman told Medscape Medical News.

Dr. Lightman, professor of clinical ophthalmology, University College of London Institute of Ophthalmology and Moorfields Eye Hospital, London, United Kingdom, and coauthors conducted a retrospective study of patients with BSCR seen at Moorfields Eye Hospital between 1993 and 2012. Of 48 patients diagnosed with BSCR, 2 tested negative for the antigen HLA-A29 and were excluded from the study. This analysis included data taken from each patient's initial examination and 1, 2, 6, and 12 months later, with follow-up information gathered at 5 and 10 years, in addition to the final follow-up visit. Visual outcomes were determined using the 6-month visit as the baseline to separate the effects of early, active disease fluctuations from more chronic changes.

For the study population of 46 patients (92 eyes), the change in BCVA, expressed as the logarithm of the minimum angle of resolution (logMAR), was 0.01 (standard error [SE], 0.08) at 10 years. Permanent visual loss occurred in only 11 eyes (12%), and severe visual loss occurred in 3 eyes (3%).

Short-term treatment was indicated for 21 patients, and long-term treatment for 25. "Treatment decisions at our clinic are based on clinical presentation and response to treatment, with the aim of stabilizing patients' inflammation using the lowest possible dose of immunosuppression," Dr. Lightman explains. "In BSCR patients, this means BCVA, clinical examination, visual field, and electroretinography." Of 50 eyes treated with immunosuppression, 43 (86%) received mycophenolate mofetil. Other immunosuppressives used were methotrexate (10 patients; 20%), cyclosporine (6 patients; 12%), and azathioprine (2 patients; 4%).

Mean visual acuity at baseline was 0.14 logMAR in patients receiving short-term treatment and 0.40 logMAR among patients receiving long-term treatment (P = .001). This was the only significant difference between the groups. Their mean ages at baseline were 57 and 54 years, respectively (P = .26).

For eyes in the short-term treatment group, mean baseline BCVA was −0.03 logMAR (SE, 0.04) and −0.03 logMar (SE, 0.03) at 2 years' follow-up (Friedman multivariate analysis of variance, P = .08). Among those receiving long-term treatment, mean BCVA at baseline was 0.1 (SE, 0.04) logMAR and had actually improved at 2 years to −0.11 (SE, 0.04) logMAR (Friedman analysis of variance, P < .001). BCVA remained stable for the duration of the study in both groups.

On multivariate analysis the researchers controlled for factors including anterior chamber cells and flare, vitreous cells or haze, retinal lesion distribution, presence of cataract, foveal leakage on fluorescein angiography, and central retinal thickness. Clinical findings associated with lower transient BCVA included cataracts, foveal leakage on fluorescein angiography, and an increase in central retinal thickness greater than 300 μm.

In the visual field evaluation, eyes in the short-term treatment group showed no progression in mean deviation over time (Spearman correlation, −0.19; P = .21) but did show a worsening of pattern standard deviation (Spearman correlation, 0.57; P = .003). Eyes in the long-term treatment group showed an improvement in mean deviation (Spearman correlation, 0.55; P < .001) and stabilization of pattern standard deviation (Spearman correlation, −0.24; P = .26), suggesting stabilization of visual field with long-term, but not short-term, treatment, the authors write. "The combined changes in [visual acuity and visual field] support an approach toward long-term immunosuppression for the prolonged stability of retinal function—first, central vision, and later, the continued resolution of peripheral retinal disease."

These findings suggest that "with modern treatment approaches, we can preserve visual acuity and visual field in patients with BSCR and even improve the visual field," Douglas A. Jabs, MD, MBA, professor and chairman of the Department of Ophthalmology, Mount Sinai School of Medicine, New York City, told Medscape Medical News. Dr. Jabs, who was not involved in this study, praised it for the length of its follow-up time and for the finding that immunosuppression is often necessary for preservation and even improvement of visual acuity and visual field. Earlier studies have produced similar findings, he said. "This strengthens our confidence" that this is the proper way to manage these patients. He adds that use of a corticosteroid, usually prednisone, plus an immunosuppressive agent such as mycophenolate is a standard treatment approach in the United States as well as the United Kingdom.

"This disease is treatable," Dr. Jabs says. "I estimate that we can preserve visual acuity in about 85% of patients, maybe more, but you need to treat at the appropriate time, before there is permanent [optical] damage. If you do that, you can preserve visual acuity and visual field, and you can actually improve the visual field."

Dr. Lightman has received consultancy fees from Allergan, GlaxoSmithKline, 4Sight, and Paraxcel; is on the advisory boards of Allergan and GlaxoSmithKline; and has received consultancy fees from Allergan. One coauthor was supported by the UK National Institute of Health Research. The other authors and Dr. Jabs have disclosed no relevant financial relationships.

JAMA Ophthalmol. Published online December 12, 2013. Abstract

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