Purpose
Birdshot chorioretinopathy (BCR) is a rare, bilateral posterior uveitis syndrome that may cause progressive vision loss. Few case series describe spectral domain optical coherence tomography (SD-OCT) findings in BCR. Our study seeks to compare specific SD-OCT findings with visual acuity to help determine the necessity and timing of additional treatments.
Methods
A retrospective chart review was performed on patients with BCR who underwent SD-OCT imaging at the Emory Eye Center. Demographic data, ophthalmic exam findings, and immunosuppressive therapies were reviewed. SD-OCT imaging was evaluated for epiretinal membrane (ERM), external limiting membrane (ELM), IS-OS junction, OS-RPE interdigitation line, cystoid macular edema (CME) and subretinal fluid (SRF). Foveal thickness was also documented and sub-classified into eyes exhibiting foveal atrophy (central subfield thickness [CST] < 150 microns) and cystoid macular edema (CST > 250 microns with intraretinal cysts). SD-OCT findings in eyes with 20/40 or better vision were compared to those with poorer than 20/40 visual acuity. A p-value < 0.05 was considered statistically significant.
Results
Forty-five eyes in 23 patients were included in this study. There were 8 males and 15 females with a mean age of 54 years, range 34-72 years. Mean logMAR visual acuity was 0.34 (Snellen VA 20/60) with 64% of eyes measuring 20/40 or better and 36% worse than 20/40 vision. Commonly identified SD-OCT findings included ERM (89%), IS-OS junction attenuation (58%), OS-RPE interdigitation line disruption (58%), ELM disruption (19%), CME (19%), SRF (5%), and foveal atrophy (2%). Of these changes, CME (p=0.037) and ELM disruption (p=0.009) were statistically associated with Snellen visual acuities worse than 20/40 (Table 1). Visually significant cataracts (6 eyes), optic disc edema (2 eyes), and macular holes (1 eye) also contributed to decreased visual acuity.
Conclusions
SD-OCT abnormalities associated with progressive retinal damage and decreased vision were common in this cohort of BCR patients. While CME and ELM disruption were independently associated with an increased likelihood of vision worse than 20/40, identification of all SD-OCT changes in this study helps determine when treatment should be escalated. Long-term follow-up is needed to evaluate whether anatomic improvements affect visual acuity.
Keywords: 746 uveitis-clinical/animal model •
451 chorioretinitis •
550 imaging/image analysis: clinical