Microperimetry findings in patients with birdshot chorioretinopathy

Objective: To assess the role of microperimetry-1 (MP1) as an ancillary tool in patients with birdshot chorioretinopathy (BSCR). Design: Observational cross-sectional study. Participants: Twenty-three eyes of 23 patients. Methods: A review of medical records was conducted of patients with BSCR seen at our institution, from January 2008 to August 2008, on whom MP I had been performed. Of the 23 eyes included in the study, 15 eyes were identified as having HLA-A29 positive BSCR; 8 eyes with no known ocular pathology were used in the analysis as the control group. The clinical status was assessed by biomicroscopy, indirect ophthalmoscopy, and fluorescein angiography. Results: When eyes with active disease were compared with eyes with inactive disease there was a statistically significant difference (p = 0.001) between them in the number of points below 16 dB. The difference was also statistically significant (p = 0.04) when it was adjusted for visual acuity, associated disease, and age. When eyes of patients with inactive disease were compared with control eyes, there was a statistically significant difference (p = 0.01) in the number of points below 16 dB, suggesting that not all patients may recover their full retinal sensitivities. When eyes of patients with active disease were compared with controls there was a statistically significant difference (p = 0.01) between them in the number of points below 16 dB after adjusting for age, visual acuity, and associated disease (macular edema and epiretinal membrane). Conclusions: Microperimetric quantification of macular sensitivity in patients with BSCR may provide an ancillary tool to evaluate activity and may help to assess visual impairment in these patients.