Authors: Keith Perry¹, Mélanie Hébert², Ryan Hendrick¹, Mohammed Al Kaabi³, Anna Polosa³ Marie-Josée Aubin³. ¹Université de Montréal, ²Hôpital Saint-Sacrement, CHU de Québec - Université Laval, ³Centre universitaire d'ophtalmologie, Hôpital Maisonneuve-Rosemont.

Author Disclosures: K. Perry: None. M. Hébert: Funded grants or clinical trials; Name of for-profit or not-for-profit organization(s); Bayer, Fighting Blindness Canada, Vision Health Research Network. Funded grants or clinical trials; Description of relationship(s); Research funding, Research funding, Research funding. R. Hendrick: None. M. Al Kaabi: None. A. Polosa: None. M. Aubin: Funded grants or clinical trials; Name of for-profit or not-for-profit organization(s); Vision Health Research Network. Funded grants or clinical trials; Description of relationship(s); Research funding.

Abstract Body: 

Purpose: To investigate the long-term outcomes in Birdshot chorioretinopathy. 

Study Design: Retrospective cohort study 

Methods: Patients with BSCR diagnosed since 1986 and followed by the uveitis service of the Centre universitaire d’ophtalmologie - Hôpital Maisonneuve-Rosemont were considered for inclusion (n=77). In this retrospective cohort study, patient files were reviewed in a standardized manner and pre-established clinical endpoints were collected at specific intervals. Data compilation was done using RedCap. 

Results: Median [Q1, Q3] duration of follow-up for the 77 patients was of 100 months [53, 163]. Median [Q1, Q3] age of this cohort at diagnosis was 53 [46, 59] years. Most BSCR patients were treated with biologics (87%). Duration of topical corticosteroids for treatment was 14 [6, 62] weeks. Periocular injections were administered in 26% of eYes, while intraocular injections were used in 21%. Cystoid macular edema (CME) defined as central subfoveal thickness (CST) greater than 295 μm occurred in 50% of eYes, while loss of visual field greater than a mean deviation of -12 was seen in 14% of eyes. Vasculitis involving two quadrants or more was reported in 24% of eyes at follow-up. Furthermore, initial CST was 287 [250, 344] μm compared to 245 [223, 288] microns at final follow-up (p=0.009). Retinal nerve fiber layer (RNFL) thickness also decreased from 106 [90, 125] μm to 93 [84, 106] μm between the initial visit and final follow-up (p<0.001). 

Conclusions: In BSCR, a major contributor to loss of vision is CME which should be treated aggressively using periocular and intraocular corticosteroid injections in addition to systemic immunomodulation. With treatment and follow-up, progressive decreases in CST and RNFL thickness are also seen.