Assessment of Visual Field Abnormalities in Patients with Birdshot Retinochoroidopathy

Abstract

Abstract: : Purpose: Patients with birdshot retinochoroidopathy (BSR) can have multiple visual complaints including dyschromatopsia, nyctalopia, and blurring of vision despite normal Snellen visual acuity. Visual field (VF) analyses have been inconsistently reported for patients with BSR, but some evidence supports the potential utility of VF data in monitoring the status of these patients. The purpose of this study was to evaluate the VF and vision acuity measurements of patients with BSR in order to determine whether VF studies, in addition to vision acuity measurements, add value in providing evidence for decreased visual function. Design: Cross-sectional case series Methods: We evaluated data from 90 eyes of 45 French patients obtained during comprehensive clinical examinations and Humphrey visual field analyses (full threshold program 30-2 with foveal threshold determination) using standard methods. The VF results were graded by one observer (LKG) who was masked with regards to visual acuity measurements and visual complaints. Results: VF abnormalities, when defined as MD > 3.0, were present in 50 eyes (55.6%), but scattered abnormalities in the VF were also noted in 60% of the patients with a MD of < 3.0. The most common VF abnormalities were scattered areas of depression (46.7% of eyes), enlargement of the blind spot (42.2% of eyes), and arcuate defects (20% of eyes). Among eyes with visual acuity > 0.9, 14.4% had substantial VF abnormalities. VF abnormalities increased to 42.2% of eyes with visual acuities of > 0.5. Although the foveal threshold was > 25 in 93.3% of eyes, this value was not related to the MD. Conclusion: VF is an important clinical marker of visual function in BSR and substantial VF abnormalities are a common finding in BSR. These abnormalities may be extensive despite preservation of central visual acuity. It is therefore possible that VF data may represent an important surrogate marker for disease activity and may be an appropriate measure for monitoring patients during therapy. Additional studies are required to determine if VF abnormalities predict additional decline in vision.

Keywords: retina • uvea • visual fields