Purpose
To report progressive posterior choroidal depigmentation during long-term follow-up in patients with birdshot chorioretinopathy (BCR) undergoing implantation with a fluocinolone acetonide containing device despite otherwise excellent control of inflammation.
Methods
Retrospective comparative case series of BCR patients from one university and two private uveitis clinics. Evaluation of baseline vs. follow-up fundus color photographs after a minimum of 30 months were compared in patients treated with the fluocinolone implant or systemic immunosuppression. Available fluorescein angiography, indocyanine green, autofluorescence, and optical coherence tomography were also compared. The primary outcome measure was an “unequivocal” change in background choroidal depigmentation on color fundus photography graded by two masked observers, compared by chi-square. Mean group follow-up time was compared by t-test.
Results
Group 1 included 10 patients (20 eyes) treated with fluocinolone implants and Group 2 included 10 patients (20 eyes) treated with immunosuppression during the study period. Both groups had similar demographics for age, sex, and initial and follow-up visual acuity. Follow-up for Group 1 was median 75 months and mean 69 months. Group 2 was median 57 months and mean 64 months (P=0.29 by t-test). Ocular inflammation in both groups improved based on clinical information and imaging studies. Evaluable photographs demonstrated depigmentation in 10 eyes of 6 patients in Group 1 and 4 eyes of 4 patients in Group 2 (chi-square 3.96, P< 0.05).
Conclusions
Patients treated with the fluocinolone implant had a higher frequency of choroidal depigmentation unassociated with RPE atrophy despite good clinical control of inflammation and preserved vision. The results may indicate a specific effect of corticosteroids on choroidal pigment or a differential effect of intravitreal vs. systemic treatment in BCR, a panuveitis that involves vitreous, retina, RPE, and choroid. Additional follow-up and standardized photographs are needed to confirm this finding and determine if similar changes occur in other types of uveitis.