Choroidal Blood Flow during Exercise-Induced Changes in the Ocular Perfusion Pressure

Purpose: Several ischemic optic neuropathies that occurred during robotic-assisted laparoscopic radical prostatectomy (RALRP) have been reported to be due to the Trendelenburg position, which lowers ocular perfusion pressure (OPP). We examined changes in pulsatile ocular blood flow (POBF) and its correlation with OPP during RALRP in the steep Trendelenburg position. Methods: Pulsatile ocular blood flow and intraocular pressure (IOP) were measured in 50 patients by the OBF Langham System 5 times during RALRP. The mean arterial blood pressure (MAP), heart rate, plateau airway pressure, and end-tidal CO2 (EtCO2) at each time point were recorded. Ocular perfusion pressure was calculated from simultaneous IOP and MAP measurements. Results: Pulsatile ocular blood flow was 15.53 ± 3.32 µL/s at T0, 18.99 ± 4.95 µL/s at T1, 10.04 ± 3.24 µL/s at T2, 11.45 ± 3.02 µL/s at T3, and 15.07 ± 3.81 µL/s at T4. Ocular perfusion pressure was 70.15 ± 5.98 mm Hg at T0, 64.21 ± 6.77 mm Hg at T1, 57.71 ± 7.07 mm Hg at T2, 51.73 ± 11.58 mm Hg at T3, and 64.21 ± 12.37 mm Hg at T4. Repeated-measures analysis of variance on POBF and OPP was significant (p>0.05). This difference disappeared when the correlation between MAP and POBF, EtCO2 and POBF, and EtCO2 and OPP were considered, while correlation between MAP and OPP confirmed the difference. The regression analysis between POBF and OPP showed a statistically significant difference at T0 and T3 (r = 0.047, p = 0.031 and r = 0.096, p = 0.002, respectively). Conclusions: Pulsatile ocular blood flow and OPP reached the lowest level at the end of surgery.

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Consequences of an Increase in the Ocular Perfusion Pressure on the Pulsatile Ocular Blood Flow

Optometry and Vision Science ◽

10.1097/01.opx.0000144748.65471.e5 ◽

2004 ◽

Vol 81 (9) ◽

pp. 692-698 ◽

Cited By ~ 18

Author(s):

JOHN V. LOVASIK ◽

H??L??NE KERGOAT

Keyword(s):

Blood Flow ◽

Perfusion Pressure ◽

Ocular Blood Flow ◽

Ocular Perfusion Pressure ◽

Ocular Perfusion ◽

Pulsatile Ocular Blood Flow

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Ocular Blood Flow Autoregulation Mechanisms and Methods

Journal of Ophthalmology ◽

10.1155/2015/864871 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 15

Author(s):

Xue Luo ◽

Yu-meng Shen ◽

Meng-nan Jiang ◽

Xiang-feng Lou ◽

Yin Shen

Keyword(s):

Blood Flow ◽

Perfusion Pressure ◽

Ocular Blood Flow ◽

Flow Regulation ◽

Main Function ◽

Ocular Diseases ◽

Ocular Perfusion Pressure ◽

Metabolic Demand ◽

Ocular Perfusion ◽

Sufficient Oxygen

The main function of ocular blood flow is to supply sufficient oxygen and nutrients to the eye. Local blood vessels resistance regulates overall blood distribution to the eye and can vary rapidly over time depending on ocular need. Under normal conditions, the relation between blood flow and perfusion pressure in the eye is autoregulated. Basically, autoregulation is a capacity to maintain a relatively constant level of blood flow in the presence of changes in ocular perfusion pressure and varied metabolic demand. In addition, ocular blood flow dysregulation has been demonstrated as an independent risk factor to many ocular diseases. For instance, ocular perfusion pressure plays key role in the progression of retinopathy such as glaucoma and diabetic retinopathy. In this review, different direct and indirect techniques to measure ocular blood flow and the effect of myogenic and neurogenic mechanisms on ocular blood flow are discussed. Moreover, ocular blood flow regulation in ocular disease will be described.

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