Assessment of macular choroidal thickness and microvascular changes in patients with systemic lupus erythematosus by swept-source OCTA

Objective

To observe the characteristics of early changes in choroidal thickness and choroidal microvascular morphology in the macula of patients with systemic lupus erythematosus (SLE) using swept-source optical coherence tomography angiography (OCTA).

Methods

A cross-sectional study was conducted.Thirty-seven patients (37 eyes) who were diagnosed with SLE without obvious ocular symptoms in Hebei General Hospital from January 2022 to July 2022 were enrolled in this study as a SLE group.At the same time, 35 normal adults (35 eyes) matched with age and sex were included as a control group.Swept-source OCT was used to perform a 9 mm×9 mm radial scan of the macular region of subjects to obtain the average choroidal thickness of the macular central concave area, the paracentral concave area (1-3 mm), and the pericentral concave area (3-6 mm). OCTA was used to perform a 3 mm×3 mm scan of the macular region and images of retinal superficial capillary plexus (SCP) and deep capillary plexus (DCP) blood flow density, choroidal capillary plexus (CC) blood flow density, and microvascular blood flow in the macular region were obtained and binarized using ImageJ software (Phansalkar method) to calculate the choroidal capillary flow void area (FDa) and percentage of flow deficits (FD%). The study protocol followed the Declaration of Helsinki and was approved by the Ethics Committee of Hebei General Hospital (No.202310). Informed consent was obtained from all subjects.

Results

The choroidal thickness of the subfoveal region in SLE group was (268.73±81.67)μm, which was significantly higher than (230.14±68.14) μm of control group (t=2.170, P=0.033). The blood flow density of SCP, DCP and CC in the macular central zone area of SLE group were (16.58±3.90)%, (14.25±3.15)% and (51.80±4.27)%, respectively, which were significantly lower than (20.55±4.41)%, (16.57±3.74)% and (54.33±3.41)% of control group (t=-4.043, -2.851, -2.763; all at P<0.05). The FDa and FD% in SLE group were 3.43(3.25, 3.56)mm² and 38.11%(36.13%, 39.52%), which were greater than 3.25(3.21, 3.32)mm² and 36.11%(35.64%, 36.84%) of control group, and the differences were statistically significant (Z=-3.470, -3.476; both at P<0.05).

Conclusions

OCTA can detect an increase in choroidal thickness and a decrease in blood flow density of CC in eyes with SLE without obvious ocular symptoms.

Systemic lupus erythematosus; Choroidal thickness; Flow deficits; Choriocapillaris; Optical coherence tomography angiography