[Macular choroidal volume in patients with highly myopic foveoschisis and its clinical value]

Objective: To study the macular choroidal volume (MCV) of patients with highly myopic foveoschisis and its clinical value. Methods: In this cross-sectional study, 39 outpatients (39 eyes) with highly myopic foveoschisis were included from January 2016 to December 2020 in Peking University People's Hospital, including 18 males and 21 females. Their age was (59.3±6.7) years old. Thirty-nine highly myopic patients (39 eyes) with no macular complications were enrolled as control group. The age, gender, and refractive error were matched between two groups. Medical history information and eye examination information including refractive error, axial length and best corrected visual acuity were recorded. All patients had undergone high-resolution enhanced depth imaging optical coherence tomography to measure the retinal and choroidal thickness of multiple parts of the macular zone. According to the image characteristics, myopic foveoschisis patients were divided into the inner and outer myopic foveoschisis subgroups, and the MCV characteristics were analyzed. The independent sample t test, Pearson correlation analysis and linear regression analysis were used. Results: The subfoveal choroidal thickness was (74.9±59.3) and (155.6±47.1) μm, and MCV was (2.3±0.8) and (5.3±1.0) mm³ in the foveoschisis group and the control group, respectively. The differences were statistically significant (t=-6.649, -15.229; P<0.01). Although no correlation was found between subfoveal choroidal thickness and central foveal thickness in both groups (r=0.103, 0.214; P>0.05), MCV was negatively correlated with macular retinal volume (MRV) in the foveoschisis group (y=-2.90x+18.48; r²=0.47, P= 0.01). In the control group, there was a positive correlation between MCV and MRV (y=0.74x+2.02; r²=0.64, P=0.01). The best corrected visual acuity was positively associated with MCV in patients with foveoschisis (r=0.677, P<0.05). The MCV of inner (19 eyes) and outer (15 eyes) foveoschisis subgroups was (2.80±0.81) and (1.92±0.27) mm³, and the difference was statistically significant (t=4.610, P<0.05). Conclusions: The MCV significantly decreased in patients with highly myopic foveoschisis. The smaller the MCV, the scarcer the blood supply of the outer retina, the more serious the foveoschisis, and the larger the MRV. (Chin J Ophthalmol, 2021, 57:419-425).