Retinal and choroidal microcirculation in fuchs uveitis syndrome after caffeine intake assessed using OCTA

To evaluate the short-term effects of a single oral intake of coffee (250 mL of water containing 200 mg of coffee powder) on retinal and choroidal microcirculation in Fuchs uveitis syndrome (FUS) using OCTA.

This prospective study included 10 FUS patients and 10 matched healthy controls (HC). Eyes were divided into FUS, fellow (FUS-F), and HC groups. All participants underwent 6 × 6 mm OCTA at baseline and 60 min post-caffeine.

A total of 12 eyes from 10 patients with FUS were analyzed, among whom 8 patients (80.0%) had unilateral involvement. Compared with FUS-F and HC, FUS eyes showed significantly reduced vessel density (VD) in the superficial capillary plexus (SCP) and decreased foveal density within 300 µm of the foveal avascular zone (FD-300), along with an enlarged foveal avascular zone (FAZ) in the total capillary plexus (TCP). In addition, FUS eyes exhibited increased retinal nerve fiber layer (RNFL) thickness and reduced choroidal thickness (CT). After caffeine intake, retinal perfusion parameters showed no significant changes except for decreased RNFL VD in the nasal and inferior sectors. In contrast, CT decreased significantly in the fovea, temporal parafovea, inferior parafovea, and temporal perifovea, accompanied by corresponding reductions in the choroidal vascularity index of medium and large choroidal vessels (3D-CVI) in FUS eyes.

FUS eyes exhibit impaired posterior microcirculation, characterized by reduced SCP VD and CT. Choroidal vessels are more sensitive to caffeine than retinal circulation, while vascular reactivity appears blunted in FUS eyes.