Abstract
Purpose :
To characterize retinal macular microvascular changes and density in individuals with birdshot chorioretinopathy.
Methods :
Fourteen eyes of 7 patients ages 36-69 years, average 57.5 years, diagnosed with HLA-A29 + birdshot chorioretinopathy underwent comprehensive retinal exam and retinal imaging using OCT-angiography (OCT-A) (AngioVue; Optovue, Inc.) where both 3 x3 mm and 6 x 6 mm scans of the macula were acquired. Foveal avascular zone (FAZ) area and vascular density were calculated and compared to an in-house normative OCT-A database of 146 subjects. Vascular density data was then overlaid onto 3x 3 mm superficial macular scans, and areas greater than 2 standard deviations from normative date were highlighted. OCT-A images were also reviewed for microvascular changes in the posterior pole.
Results :
Visual acuity ranged from 20/20 to 20/50 for all eyes. All individuals were on immunosuppressive agents for birdshot chorioretinopathy. Seven of 14 eyes had an epiretinal membrane(ERM) involving the macula, with 5 eyes having only trace ERM. A lamellar hole/ERM was present in one eye and ERM traction of the macula was present in one eye, excluding these eyes from further FAZ area and vascular density analysis. Four eyes had a history of previous cystoid macular edema, although resolved at the time of image acquisition. OCT-A demonstrated irregularities of the FAZ in all eyes, with 12 eyes having irregular shaped and/or enlarged FAZ and 2 eyes of one patient having no defined FAZ. Mean FAZ area of 10 of 14 eyes (0.35mm2) was significant larger when compared to mean FAZ area in the normative database (0.27 mm2 p= 0.02, Mann-Whitney test). Macular vascular density was calculated for 6 of 14 eyes, and showed multiple areas throughout the 3x3 mm image where density was greater than 2 standard deviations from normal. Review of OCT-A images showed capillary dilation and vascular looping in all 14 eyes. Additionally, anomalous vessels were present in 2 eyes.
Conclusions :
Significant retinal microvascular anomalies exist in the macula of patients with birdshot chorioretinopathy that are not appreciated with conventional clinical imaging, even when visual acuity is preserved and inflammation is well controlled.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.