Abstract
Purpose :
Birdshot chorioretinitis (BSCR) is a chronic posterior uveitis which can lead to different types of retinal tissue damage with consequences on vision. Epiretinal membranes (ERM) are a frequent complication of inflammatory chronic intraocular disorders and we focused our study on their frequency, characteristics and impact in patients with BSCR. Our analyses were based on a prospective, observational, single center, cohort study.
Methods :
The patients from the CO-BIRD study (NCT05153057) imaged by the OCT HRA Spectralis were included. Patients with a history of macular hole or retinal detachment surgery were excluded. Our study’s main outcome measure was the frequency of ERM in patients with BSCR. The patients’ last visit was used for the study purposes. The ERM were classified according to the Govetto classification by two independent observers. Peeled ERM were evaluated separately and classified with to the pre-operative OCT when available. The central minimal thickness (CMT) and foveolar thickness (CFT) were recorded. Comparisons between the OCT findings, the best corrected visual acuity (BCVA) and the foveal threshold (FT) measured by the Humphrey visual field analyzer were also performed. The differences between groups were assessed by the Kruskal-Wallis and Chi-2 tests.
Results :
We studied 428 patients (179 males, 249 females) (852 eyes) with a mean age of 63±13 years and a mean time elapsed since the first symptoms associated with BSCR of 13.7±8.6 years. An ERM was observed in 103 eyes (12.09 %) and 14 (1.64 %) had prior peeling surgery. Govetto stage 1 ERM were observed in 93 eyes (10.92 %) and stage 2 in 10 eyes (1.17%). No Govetto stage 3 or 4 ERM were detected. The mean CMT was 207±57µm in eyes without an ERM and thicker (224±42µm and 383±130µm) in eyes with stages 1 and 2 ERM (p<0,001). Similarly, the mean CFT was 256±63µm, 283±43µm and 422±141µm in the same groups (p<0,001). The mean LogMAR BCVA was 0.24±0.49 in the eyes without an ERM, 0.11±0.29 in stage 1 and 0.20±0.32 in stage 2 eyes (p=0,005). The mean FT was 32.20±4.84 dB, without a significant difference (p=0,3) between the 3 groups.
Conclusions :
Our study showed that ERM are a common complication of BSCR, but none belonged to the advanced 3 or 4 stages of the Govetto classification. The visual impact of ERM associated with BSCR was mild. Whether these ERM require a specific treatment strategy remains to be determined.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.