Effects of Different MAP Targets on Ocular Perfusion and Optic Nerve Microvasculature During Rhinoplasty
Effects of Different Mean Arterial Pressure Targets on Ocular Perfusion and OCTA-Derived Optic Nerve Head Microvasculature During Controlled Hypotension in Rhinoplasty: A Prospective Randomized Controlled Trial
This randomized controlled trial aims to evaluate the effects of two different mean arterial pressure (MAP) targets during controlled hypotension on ocular perfusion and optic nerve head microvasculature in patients undergoing elective rhinoplasty or septorhinoplasty.
A total of 60 patients will be randomized in a 1:1 ratio to a target MAP of either 50-60 mmHg or 60-70 mmHg during general anesthesia. Intraocular pressure (IOP) will be measured at predefined perioperative time points, and estimated ocular perfusion pressure (OPP) will be calculated using simultaneous MAP and IOP measurements. Optical coherence tomography angiography (OCTA) will be performed preoperatively and postoperatively to assess changes in peripapillary, optic nerve head, and macular microvascular parameters.
The primary objective is to compare changes in peripapillary vessel density between the two MAP target groups. Secondary objectives include evaluating changes in optic nerve head microvasculature, intraoperative OPP and IOP, and the relationships between the depth and duration of hypotension and OCTA-derived microvascular changes.
Study Overview
Status
Conditions
Intervention / Treatment
Detailed Description
Controlled hypotension is commonly used during rhinoplasty to reduce intraoperative bleeding and improve surgical field visibility. However, reductions in mean arterial pressure (MAP) may also decrease ocular perfusion pressure (OPP), particularly when accompanied by changes in intraocular pressure (IOP). Although perioperative ischemic optic neuropathy is rare, hypotension and other factors that reduce tissue perfusion have been reported as potential contributors to perioperative visual complications. The effects of different controlled hypotension targets on ocular perfusion and optic nerve head microvasculature during rhinoplasty remain insufficiently characterized.
This prospective randomized controlled trial will include 60 patients aged 18-50 years with American Society of Anesthesiologists (ASA) physical status I-II who are scheduled for elective rhinoplasty or septorhinoplasty under general anesthesia. Participants will be randomized in a 1:1 ratio using computer-generated block randomization to one of two intraoperative controlled hypotension strategies: a target MAP of 50-60 mmHg or a target MAP of 60-70 mmHg. Participants and the ophthalmologist performing the postoperative OCTA assessment will be blinded to group allocation, whereas the attending anesthesiologist and surgeon will not be blinded.
All patients will receive standardized general anesthesia. MAP and other standard monitoring parameters will be continuously monitored. IOP will be measured noninvasively in the same eye using tonometry at predefined perioperative time points: before induction of anesthesia, after endotracheal intubation, after achieving the target MAP, 15 minutes after establishment of controlled hypotension, every 30 minutes thereafter during maintained hypotension, at the end of surgery, and during the early post-extubation period. MAP will be recorded simultaneously with each IOP measurement, and estimated OPP will be calculated as MAP minus IOP.
Optical coherence tomography angiography (OCTA) will be performed using the same device before surgery and during postoperative follow-up. Preoperative OCTA will be obtained 1-7 days before surgery, and postoperative assessments will be performed within 24-72 hours, at 1 week, and at 1 month. OCTA-derived parameters will include peripapillary vessel density, optic nerve head vessel density, and superficial and deep macular vascular density.
The primary outcome is the change in peripapillary vessel density from the preoperative measurement to the early postoperative assessment. Secondary outcomes include changes in optic nerve head and macular microvascular parameters, minimum intraoperative estimated OPP, maximum change in IOP, and the relationships between the depth and duration of controlled hypotension and postoperative OCTA-derived microvascular changes.
The study is designed to determine whether different MAP targets used during controlled hypotension are associated with different patterns of ocular perfusion and subclinical optic nerve head microvascular change. The study is not designed to determine the incidence of perioperative ischemic optic neuropathy or other rare postoperative visual complications.
Study Type
Enrollment (Estimated)
Phase
- Not Applicable
Contacts and Locations
Study Contact
- Name: Sibel ÖNEN ÖZDEMİR
- Phone Number: +905442892194
- Email: sibelonen89@gmail.com
Study Locations
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-
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Çorum, Turkey (Türkiye)
- Recruiting
- Hitit university
-
Contact:
- Ozgur Yagan, Professor
- Phone Number: +90 364 222 11 00
- Email: tipfak@hitit.edu.tr
-
-
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- Age 18-50 years
- Scheduled for elective rhinoplasty or septorhinoplasty
- American Society of Anesthesiologists (ASA) physical status I-II
- Willing and able to provide written informed consent
Exclusion Criteria:
- History of glaucoma, retinal disease, optic neuropathy, or other significant ophthalmologic disease
- Previous ocular surgery
- High myopia
- Uncontrolled hypertension, diabetes mellitus, or other serious systemic disease
- ASA physical status III or higher
- Development of severe intraoperative hemodynamic instability
- Massive intraoperative bleeding
- Inadequate OCTA image quality for analysis
- Pregnancy
- Refusal to participate or withdrawal of consent
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Prevention
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Double
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Experimental: Lower MAP Target (50-60 mmHg)
Participants assigned to this group will undergo controlled hypotension during general anesthesia with a target mean arterial pressure (MAP) of 50-60 mmHg. Hemodynamic parameters will be continuously monitored, and the anesthetic regimen will be titrated to maintain MAP within the assigned target range while ensuring clinical safety. |
Controlled hypotension will be maintained with a target mean arterial pressure (MAP) of 50-60 mmHg during general anesthesia. MAP will be continuously monitored, and anesthetic management will be titrated as clinically appropriate to maintain the assigned target range. |
|
Active Comparator: Higher MAP Target (60-70 mmHg)
Participants assigned to this group will undergo controlled hypotension during general anesthesia with a target mean arterial pressure (MAP) of 60-70 mmHg. Hemodynamic parameters will be continuously monitored, and the anesthetic regimen will be titrated to maintain MAP within the assigned target range while ensuring clinical safety. |
Controlled hypotension will be maintained with a target mean arterial pressure (MAP) of 60-70 mmHg during general anesthesia. MAP will be continuously monitored, and anesthetic management will be titrated as clinically appropriate to maintain the assigned target range. |
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Change in Peripapillary Vessel Density at 24-72 Hours After Surgery
Time Frame: Preoperative baseline (1-7 days before surgery) to 24-72 hours after surgery
|
Change in peripapillary vessel density measured by optical coherence tomography angiography (OCTA) from the preoperative baseline to 24-72 hours after surgery. Vessel density will be quantified using the same OCTA device and scanning protocol for all assessments. The primary comparison will be the difference in change from baseline between the two randomized MAP target groups. |
Preoperative baseline (1-7 days before surgery) to 24-72 hours after surgery
|
Collaborators and Investigators
Sponsor
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Estimated)
Study Completion (Estimated)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- 2026-136
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
IPD Plan Description
De-identified individual participant data that underlie the results reported in the published article may be made available upon reasonable request to the corresponding author. Data will be shared for scientifically sound research purposes, subject to approval by the study investigators and in accordance with applicable ethical and institutional requirements. No directly identifiable participant information will be shared.
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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