J Korean Ophthalmol Soc.  2023 Nov;64(11):1001-1008. 10.3341/jkos.2023.64.11.1001.

Novel Method Measuring Conjunctival Microvascular Blood Flow Velocity by Zoom-lens, Ultra-high-speed Camera Attached Slit-lamp Biomicroscope

• Kim HS
• Kim DR
• Yoon YC
• Yang SW
• Yoo YS
• Whang WJ
• Byun YS
• Hwang HB
• Na KS
• Lee HS
• Chung SH
• Kim EC
• Cho YK
• Kim HS
• Hwang HS

• KMID: 2547862
• DOI: http://doi.org/10.3341/jkos.2023.64.11.1001

Abstract

Purpose
To introduce an intuitive method for measuring conjunctival microvascular blood flow velocity by imaging bulbar conjunctival microvessels using a slit-lamp biomicroscope equipped with a zoom lens and an ultra-high-speed camera.
Methods
After obtaining consent from 10 patients (1 male, 9 females) who visited Yeouido St. Mary’s Hospital from August 21, 2020, to June 12, 2021, the patients were examined under a slit lamp microscope equipped with an ultra-high-speed camera and zoom lens. The blood flow in the conjunctival microvessels was photographed. The captured images were analyzed with ImageJ software to measure the blood flow velocity in the conjunctival microvessels, and we investigated whether the blood flow velocity correlated with the vessel diameter and age.
Results
The median age of the subjects was 49.0 years. The mean conjunctival blood flow velocity in 53 microvessels was 0.786 ± 0.468 mm/s. The median conjunctival microvascular diameter was 7.06 μm (interquartile range 5.84 to 9.23 μm). The conjunctival microvascular diameter and blood flow velocity were not significantly correlated (Spearman’s p = 0.177), and the subjects’ age and conjunctival microvascular blood flow velocity were also not correlated (Spearman’s p = 0.669).
Conclusions
In this study, the blood flow velocity in the bulbar conjunctival microvessels could be measured easily by means of image analysis using a slit-lamp microscope equipped with an ultra-high-speed camera with a zoom lens.

Keyword

Blood flow velocity, Conjunctiva, Microvascular, Slit lamp biomicroscope