Prevalence of cystoid macular edema and stability in OCT retinal thickness in eyes with retinitis pigmentosa during a 48-week lutein trial

Purpose: To describe, in a group of patients with moderately advanced retinitis pigmentosa (RP), the prevalence of cystoid macular edema (CME), the variation in foveal thickness over a 48-week period, the correlation of visual acuity (VA) with retinal thickness, and the lack of response of CME to lutein administration. Methods: Optical coherence tomography (OCT) imaging of the macula and clinical examination were evaluated for 77 eyes of 39 patients with RP over 11 months, with a scan done every 6 weeks. Results: The prevalence of CME, defined by cysts visible on OCT, was 49%. Bilateral CME was present in 44% of patients (17 of 39), and an additional two patients had unilateral CME. Central retinal thickness varied little over the 48 weeks. Sixty-six percent of the eyes with CME had VA of 20/40 or better. The eyes with CME with VA worse than 20/40 had either greater degrees of thickening or in fact had lower thickness measures. For the eyes without CME, the eyes with VA worse than 20/40 tended to have lower retinal thickness than the eyes with VA of 20/40 or better. VA was highly concordant between eyes, and did not differ significantly between the groups with and without CME. Lutein did not show a statistically significant effect on retinal thickness in the patients with or without CME, nor was such an effect observed in subgroups of patients with vision better or worse than 20/40. Conclusion: The prevalence rate of CME is higher than in previous reports, perhaps because the patients had some preserved macular vision and because of the use of a definition based on OCT findings. Retinal thickness remains fairly stable over time, both in eyes with CME and in eyes without CME.