Hemoglobin Video Imaging Provides Novel In Vivo High-Resolution Imaging and Quantification of Human Aqueous Outflow in Patients with Glaucoma

Autor: Tasneem Z Khatib, Yusuf Mushtaq, Keith R Martin, Ilya Manyakin, Paul A R Meyer, Jed Lusthaus
Rok vydání: 2019
Předmět:
Adult
Male
SLT
selective laser trabeculoplasty
Intraocular pressure
medicine.medical_specialty
CSA
cross-sectional area
MIGS
minimally invasive glaucoma surgery
genetic structures
Minimally invasive glaucoma surgery
Pulsatile flow
Glaucoma
Trabeculectomy
01 natural sciences
Article
Aqueous Humor
Hemoglobins
03 medical and health sciences
0302 clinical medicine
HVI
hemoglobin video imaging
In vivo
Ophthalmology
medicine
Humans
Prospective Studies
0101 mathematics
Vein
Intraocular Pressure
business.industry
010102 general mathematics
General Medicine
Middle Aged
medicine.disease
IOP
intraocular pressure
eye diseases
MD
mean deviation
medicine.anatomical_structure
030221 ophthalmology & optometry
Female
Laser Therapy
sense organs
Apraclonidine
Hemoglobin
Visual Fields
business
Biomarkers
Glaucoma
Open-Angle
medicine.drug
Zdroj: Ophthalmology. Glaucoma
ISSN: 2589-4196
DOI: 10.1016/j.ogla.2019.04.001
Popis: Purpose Noninvasive, detailed measurement of the dynamics of human aqueous outflow is difficult to achieve with currently available clinical tools. We used hemoglobin video imaging (HVI) to develop a technique to image and quantify human aqueous outflow noninvasively and in real time. Design A prospective observational study to describe characteristics of aqueous veins and a pilot prospective interventional feasibility study to develop quantification parameters. Participants Patients were recruited from the Cambridge University Hospitals NHS Foundation Trust Glaucoma clinic. The observational study included 30 eyes, and the pilot interventional feasibility study was performed on 8 eyes undergoing selective laser trabeculoplasty (SLT). Our SLT protocol also included the installation of pilocarpine and apraclonidine eye drops. Methods Participants underwent HVI alongside their usual clinic visit. Main Outcome Measures The change in cross-sectional area (CSA) of the aqueous column within episcleral veins was correlated with intraocular pressure (IOP) reduction and change in visual field mean deviation (MD) before and after intervention. Fluctuations in contrast and pixel intensity of red blood cells in an aqueous vein were calculated to compare the flow rate before and after intervention using autocorrelation analysis. Results Hemoglobin video imaging enables the direct observation of aqueous flow into the vascular system. Aqueous is seen to centralize within a laminar venous column. Flow is pulsatile, and fluctuations of flow through globe pressure or compression of the aqueous vein are observed. There was a significant increase in the aqueous column after the administration of our SLT protocol (n = 13; P < 0.05). This correlated with the degree of IOP reduction (n = 13; Pearson’s correlation coefficient 0.7; P = 0.007) and the improvement in MD observed postintervention (n = 8; Pearson’s correlation coefficient 0.75; P = 0.03). Autocorrelation analysis demonstrated a faster rate of decay in an aqueous vein after intervention, indicating an increase in flow rate. Conclusions Hemoglobin video imaging can be incorporated into a routine clinic slit-lamp examination to allow a detailed assessment and quantification of aqueous outflow in real time. It has the potential to be used to help target therapeutic interventions to improve aqueous outflow and further advance our understanding of aqueous outflow dysregulation in the pathogenesis of glaucoma.
Databáze: OpenAIRE
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