An interventional study of Lower MAP Target Strategy (50-60 mmHg) and Higher MAP Target Strategy (60-70 mmHg) in Controlled Hypotension for Nasal Surgeries, sponsored by Hitit University. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-14.
Sponsored by Hitit University · Not applicable, Interventional, and Prevention
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.
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.
55 studies on the registry are indexed under Optic Neuropathy, Ischemic; 11 are open to participants now.
This study's planned enrollment of 60 is above the median of 40 across 35 interventional studies indexed under Optic Neuropathy, Ischemic.
Browse Optic Neuropathy, Ischemic studies →Hitit University is the lead sponsor of 87 studies on the registry; 29 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
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You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Other: Lower MAP Target Strategy (50-60 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.
Other: Higher MAP Target Strategy (60-70 mmHg)
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.
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.
Change in Peripapillary Vessel Density at 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.
Time frame: Preoperative baseline (1-7 days before surgery) to 24-72 hours after surgery
Plan to share: No — 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.
No publications or documents are linked to this record.
Started Sep 2026 (actual). Primary completion is estimated for Dec 2026, 2 months after the start.
Start moved once since we started tracking on Sep 25, 2026: Jul 2026 → Sep 2026, on Oct 14, 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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