Abstract
Purpose :
Swept-source optical coherence tomography (SSOCT) enables a clear measurement of subfoveal CT (choroidal thickness), which is affected by hemodynamic factors. However, the relationship between CT and retinal vessel caliber measurement [central retinal artery/vein equivalent (CRAE/CRVE), arteriole-to-venule ratio (AVR)] remains unclear. The purpose of this study was to examine subfoveal CT in regard to the retinal vascular caliber in glaucoma patients.
Methods :
This study involved 54 primary open-angle glaucoma (POAG) patients (17 males and 37 females; mean age: 54.6±13.3 years) without macular diseases and long axial length (AL) (≥27mm) and no history of diabetes, hyperlipidemia, or hypertension treatment who underwent bilateral SSOCT and retinal imaging at Oike-Ikeda Eye Clinic, Kyoto, Japan from January to February 2016. We calculated the retinal vessel caliber by Interactive Vessel Analysis (IVAN) software (University of Wisconsin, Madison, WI) using the Parr-Hubbard and Knudtson formulas. The patients were divided into two groups based on the existence of laterality [i.e., CT difference between right and left eye; thick CT (CT-Thk) being 1.5-times thicker than thin CT (CT-Thn): 1) Laterality Group (n=7 patients) and 2) Non-Laterality Group (n=47 patients). Moreover, the CT of both eyes of each patient was compared and classified into two groups: 1) CT-Thk Group (i.e., thicker CT), and 2) CT-Thn Group (i.e., thinner CT). Next, retinal vessel caliber, CT, and CVF were compared between the CT-Thk Group and CT-Thn Group in the 13 Laterality-Group patients and the total 54 patients (paired t-test). To examine the differences of each parameter between the Laterality-Group and Non-Laterality-Group patients, and unpaired t-test was then performed. Next, the existence of laterality was used as an objective variable to perform multivariate analyses of patient age, gender, AL, systolic blood pressure/diastolic blood pressure, and retinal vessel caliber in both the CT-Thk Group and CT-Thn Group.
Results :
The paired t-test findings of the total 54patients and the Laterality-Group patients revealed significance only in CT (p<0.001). Multivariate analyses findings revealed CRVE as the significant factor (p<0.05), which was reconfirmed by un-paired t-test (p<0.05).
Conclusions :
Narrower CRVE is a factor related to CT laterality.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.