Evaluation of the retinal hemodynamics in patients with primary open angle glaucoma and differing nocturnal blood pressure profiles

Purpose: To evaluate the retinal hemodynamic response to normoxic hypercapnia among patients with primary open angle glaucoma (POAG) and differing nocturnal blood pressure (NBP) profiles, using Doppler spectral-domain optical coherence tomography (SD-OCT). Methods: Doppler SD-OCT retinal blood flow...

Full description

Bibliographic Details
Main Authors:	Yusof, Firdaus, Cheng, Richard, Espahbodi, Nadia, Khuu, Lee-Anne, Buys, Yvonne M, Trope, Graham, Hudson, Christopher, Flanagan, John G
Format:	Conference or Workshop Item
Language:	English
Published:	2014
Subjects:	RE Ophthalmology
Online Access:	http://irep.iium.edu.my/40377/ http://irep.iium.edu.my/40377/1/Abstract_FYA_ARVO_2014.pdf

id	iium-40377
recordtype	eprints
spelling	iium-403772014-12-30T01:58:48Z http://irep.iium.edu.my/40377/ Evaluation of the retinal hemodynamics in patients with primary open angle glaucoma and differing nocturnal blood pressure profiles Yusof, Firdaus Cheng, Richard Espahbodi, Nadia Khuu, Lee-Anne Buys, Yvonne M Trope, Graham Hudson, Christopher Flanagan, John G RE Ophthalmology Purpose: To evaluate the retinal hemodynamic response to normoxic hypercapnia among patients with primary open angle glaucoma (POAG) and differing nocturnal blood pressure (NBP) profiles, using Doppler spectral-domain optical coherence tomography (SD-OCT). Methods: Doppler SD-OCT retinal blood flow (RBF) measurement was acquired using the circum-papillary double circular scan protocol of the RTVue system (Optovue Inc., Freemont, CA). The sample consisted of 17 healthy controls (group mean age 62±7 years; group mean NBP dip 14±8%); 17 POAG with normal NBP dip (age 66±9 years; NBP dip 11±5%), termed “dippers”; and 16 POAG with high NBP dip (age 64±7 years; NBP dip 24±5%), “over-dippers”. The NBP dip magnitude was calculated by taking the difference between mean arterial pressure (MAP) during the day and night while awake and asleep, respectively. Automated gas blender (RespiractTM, Thornhill Research Inc., Toronto) was used to stably provoke normoxic hypercapnia (15% increase in the end-tidal carbon dioxide partial pressure relative to homeostatic baseline). Six Doppler SDOCT RBF scans were acquired, during baseline and also during normoxic hypercapnia. RBF parameters were calculated and ANOVA was used to compare values between groups (p<0.05). Results: Total RBF at baseline was significantly different between the groups with controls being the highest (37.1±4.4mL/min), and over-dippers the lowest (29.6±9.0mL/min). Venous area showed significant differences at baseline between the groups with the lowest value in the over-dipper group, and the highest in the control group (39.9±7.0(x10-3)mm, and 46.6±6.6x(10-3)mm, respectively). Velocity was not significantly different between groups (p=0.27) at baseline. Breathing normoxic hypercapnia provoked an increase in flow that was significantly lower in the over-dipper group (1.0±8.6mL/min) and highest in the controls (8.2±10.8mL/min). Change in velocity was significantly different (p=0.02) between the groups, being highest in the control group (2.4±3.3mm/s) and lowest in the over-dipper group (-0.6±3.1mm/s). Venous area change was not significantly different between groups. Conclusions: Patients with POAG who exhibited an exaggerated nocturnal reduction in MAP also demonstrated lower baseline RBF values and an impeded retinal vascular response to normoxic hypercapnia, indicating greater vascular dysregulation in this group. 2014 Conference or Workshop Item PeerReviewed application/pdf en http://irep.iium.edu.my/40377/1/Abstract_FYA_ARVO_2014.pdf Yusof, Firdaus and Cheng, Richard and Espahbodi, Nadia and Khuu, Lee-Anne and Buys, Yvonne M and Trope, Graham and Hudson, Christopher and Flanagan, John G (2014) Evaluation of the retinal hemodynamics in patients with primary open angle glaucoma and differing nocturnal blood pressure profiles. In: ARVO 2014 Annual Meeting , May 6th, 2014, Orlando, FL, USA.
repository_type	Digital Repository
institution_category	Local University
institution	International Islamic University Malaysia
building	IIUM Repository
collection	Online Access
language	English
topic	RE Ophthalmology
spellingShingle	RE Ophthalmology Yusof, Firdaus Cheng, Richard Espahbodi, Nadia Khuu, Lee-Anne Buys, Yvonne M Trope, Graham Hudson, Christopher Flanagan, John G Evaluation of the retinal hemodynamics in patients with primary open angle glaucoma and differing nocturnal blood pressure profiles
description	Purpose: To evaluate the retinal hemodynamic response to normoxic hypercapnia among patients with primary open angle glaucoma (POAG) and differing nocturnal blood pressure (NBP) profiles, using Doppler spectral-domain optical coherence tomography (SD-OCT). Methods: Doppler SD-OCT retinal blood flow (RBF) measurement was acquired using the circum-papillary double circular scan protocol of the RTVue system (Optovue Inc., Freemont, CA). The sample consisted of 17 healthy controls (group mean age 62±7 years; group mean NBP dip 14±8%); 17 POAG with normal NBP dip (age 66±9 years; NBP dip 11±5%), termed “dippers”; and 16 POAG with high NBP dip (age 64±7 years; NBP dip 24±5%), “over-dippers”. The NBP dip magnitude was calculated by taking the difference between mean arterial pressure (MAP) during the day and night while awake and asleep, respectively. Automated gas blender (RespiractTM, Thornhill Research Inc., Toronto) was used to stably provoke normoxic hypercapnia (15% increase in the end-tidal carbon dioxide partial pressure relative to homeostatic baseline). Six Doppler SDOCT RBF scans were acquired, during baseline and also during normoxic hypercapnia. RBF parameters were calculated and ANOVA was used to compare values between groups (p<0.05). Results: Total RBF at baseline was significantly different between the groups with controls being the highest (37.1±4.4mL/min), and over-dippers the lowest (29.6±9.0mL/min). Venous area showed significant differences at baseline between the groups with the lowest value in the over-dipper group, and the highest in the control group (39.9±7.0(x10-3)mm, and 46.6±6.6x(10-3)mm, respectively). Velocity was not significantly different between groups (p=0.27) at baseline. Breathing normoxic hypercapnia provoked an increase in flow that was significantly lower in the over-dipper group (1.0±8.6mL/min) and highest in the controls (8.2±10.8mL/min). Change in velocity was significantly different (p=0.02) between the groups, being highest in the control group (2.4±3.3mm/s) and lowest in the over-dipper group (-0.6±3.1mm/s). Venous area change was not significantly different between groups. Conclusions: Patients with POAG who exhibited an exaggerated nocturnal reduction in MAP also demonstrated lower baseline RBF values and an impeded retinal vascular response to normoxic hypercapnia, indicating greater vascular dysregulation in this group.
format	Conference or Workshop Item
author	Yusof, Firdaus Cheng, Richard Espahbodi, Nadia Khuu, Lee-Anne Buys, Yvonne M Trope, Graham Hudson, Christopher Flanagan, John G
author_facet	Yusof, Firdaus Cheng, Richard Espahbodi, Nadia Khuu, Lee-Anne Buys, Yvonne M Trope, Graham Hudson, Christopher Flanagan, John G
author_sort	Yusof, Firdaus
title	Evaluation of the retinal hemodynamics in patients with primary open angle glaucoma and differing nocturnal blood pressure profiles
title_short	Evaluation of the retinal hemodynamics in patients with primary open angle glaucoma and differing nocturnal blood pressure profiles
title_full	Evaluation of the retinal hemodynamics in patients with primary open angle glaucoma and differing nocturnal blood pressure profiles
title_fullStr	Evaluation of the retinal hemodynamics in patients with primary open angle glaucoma and differing nocturnal blood pressure profiles
title_full_unstemmed	Evaluation of the retinal hemodynamics in patients with primary open angle glaucoma and differing nocturnal blood pressure profiles
title_sort	evaluation of the retinal hemodynamics in patients with primary open angle glaucoma and differing nocturnal blood pressure profiles
publishDate	2014
url	http://irep.iium.edu.my/40377/ http://irep.iium.edu.my/40377/1/Abstract_FYA_ARVO_2014.pdf
first_indexed	2023-09-18T20:57:55Z
last_indexed	2023-09-18T20:57:55Z
_version_	1777410428785131520

Evaluation of the retinal hemodynamics in patients with primary open angle glaucoma and differing nocturnal blood pressure profiles

Similar Items