Abstract
Purpose: :
To describe a method of measuring large retinal blood vessels diameter using spectral-domain optical coherence tomography (SD-OCT).
Methods: :
A prospective study. 29 healthy subjects (58 eyes) with a mean age of 41.45 ±15.53 years, without any prior ocular history underwent SD-OCT exam. Two cube scans composed of seven horizontal scans each, were placed at the superior and inferior borders of the disc (one cube scan superiorly and one cube scan inferiorly) to include the large retinal vessels originating from the disc The diameter of the temporal retinal arteries and veins was measured and an artery to vein ratio (a-v ratio) was calculated at 10 measurement points (480-1440 µm from the optic disc border superiorly and inferiorly).
Results: :
Average retinal artery and vein diameter (µm) was 135.73 µm +/-15.64 and 151.32 µm +/-15.22 at the nearest measurement point at 480 µm with gradual decrease to 123.01 +/- 13.43 and 137.69 +/-13.84 at 1440 µm, respectively. No statistical difference was found in mean arterial diameter between the superior and inferior arteries and between the right and left eyes at all measurement points. No statistical difference was found in mean venous diameter between the superior and inferior veins. Statistical significance between veins diameter in the right and left eyes was found only at 960 and 1200 µm measurements points. The artery-vein ratio (a-v ratio) was ~ 0.9 at all measurement points.
Conclusions: :
This is a novel non invasive method for retinal blood vessels diameter measurement using the SD OCT imaging modality. This method coupled with the infrared image may be useful for accurate evaluation of retinal vascular caliber in retinal as well as systemic vascular diseases. It may serve in the future for diagnosis and follow up of various primary and secondary ocular vascular abnormalities.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical