Name

Évaluation de l’atrophie péripapillaire chez les patients atteints de choriorétinopathie de birdshot

To analyze peripapillary atrophy (PPA) in patients with birdshot chorioretinitis. We studied its frequency, extent, and relation with measures of visual function.

Participants were patients included in the CO-BIRD cohort. The areas of the Optic Nerve Head (ONH) and PPA were measured and analyzed based on red-green and autofluorescence fundus images acquired by the ultra-widefield retinal photography. The images from the last visit were used. The disease duration was approximated as the time elapsed since the first symptoms. The other parameters recorded were the patients’ age, best corrected visual acuity (BCVA) and the results of visual field testing (30-2) with the Humphrey perimeter.

A total of 752 eyes from 384 patients with a mean age of 62.4±12.1 years were included. 

The median disease duration was 13.0 (12.0) years. A PPA was observed in 717 (95.4%) eyes. The mean PPA/ONH ratio measured on red-green images was 2.9±2.2 and 3.1±2.2 on autofluorescence images. Measurements with these 2 imaging modalities were highly correlated (R = 0.95, p < 0.0001). The ratio of PPA/ONH increased with the duration of the disease (R = 0.57, p < 0.0001) from 1.6 ± 0.6  in the 0-5 years group, to 5.2±2.9 after 25 years. Age was another parameter correlated with this ratio (R = 0.51, p < 0.0001). PPA was also associated with a worse BCVA (R = -0.42, p < 0.0001), as well as worse visual field results: MD (R = -0.41, p < 0.0001) and PSD (R = 0.42, p < 0.0001). A strong intereye symmetry of the PPA/ONH ratio was observed (R = 0.91, p < 0.0001), which was greater than that of BCVA (R = 0.58, p < 0.0001), MD (R = 0.76, p < 0.0001) or PSD (R = 0.70, p < 0.0001).

We observed PPA in 94% of the patients with BSCR, an almost constant finding in the later stages of the disease. The frequency and the extent of PPA increased with age and disease duration, with a significantly greater impact of the later. Larger areas of PPA were associated both with worse visual acuity and visual field results. The mechanism leading to PPA in BSCR remains to be understood. It could be linked to chronic leakage around the disk from papillitis, but also from a privileged localization of lymphocytic infiltrates in the choroidal area adjacent to the disk. Furthermore, the area of PPA was more symmetrical, than BCVA, MD or PSD.

Almost all patients with BSCR exhibit PPA, which increases over time and is associated with poorer vision.