Completed

NCT Number: NCT02342288

Intraoperative Ocular Pressure in Lumbar Spine Fusion Patients

A rare but terrible complication of vision loss has been known to occur after surgery, including spine surgery. It is commonly thought that increased intraocular pressure (IOP) is one of the reasons for this rare vision loss. It has been shown that the prone position can increase the IOP, and that tilting the patient with the head down can also increase IOP. The investigators will be measuring IOP before, during, and after a posterior spine surgery to see if the investigators can influence the intraocular pressure with elevated head position change. Two groups will be studied: one group of patients will receive standard care with the head in neutral position, while the other group will have the head slightly elevated 10 degrees during prone spine surgery.

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Key information

Conditions

Raised Ocular Pressure

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

About this study

It has been reported that postoperative vision loss after lumbar surgery is increasing. It is an uncommon but devastating complication. One of the risk factors that has been reported is increased intraocular pressure (IOP), which may decrease perfusion pressure to the optic nerve. Intraocular pressure in anesthetized, prone spine patients has been studied with the head in neutral position. The prone position and duration of the procedure did increase the IOP. Our hypothesis is that adjusting the position of the head in space will alter the intraocular pressure, with an extended position decreasing IOP. This study is a, randomized, controlled design: neutral head position (standard care) or extended head position (intervention group). Patients who qualify for spinal fusion surgery and meet the inclusion criteria will be randomized to either the neutral (standard practice) or the intervention group.Randomization of patients will be computer generated.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Patients undergoing elective lumbar spinal fusion surgery; ages 18-80

Exclusion criteria

Less than 18 years of age
Glaucoma, previous eye surgery, eye injury, or eye trauma, cervical myelopathy, prior cervical spine surgery, current neoplasm, patients who have neck pain with 10 degrees active extension.

Treatment and study plan

Head raised 10 degrees

Procedure

Baseline measurement in seated position; anesthetization in the supine position. Prior to turning into the prone position, another measurement was taken. Five minutes after turning prone, a third IOP measurement was obtained. Head was raised to 10 degrees. After 5 minutes a fourth IOP measurement was performed. Repeat measurements were taken every 15 minutes until three sequential measurements were within plus or minus 3 mmHg of one another; thereafter, measurements were obtained every hour until end of case. A final measurement was taken after turning the patient supine and 5 minutes elapsed for equilibration.

Head in neutral position

Procedure

Baseline measurement in seated position; anesthetization in the supine position. Prior to turning into the prone position, another measurement was taken. Five minutes after turning prone, a third IOP measurement was obtained. After 5 minutes a fourth IOP measurement was performed. Repeat measurements were taken every 15 minutes until three sequential measurements were within plus or minus 3 mmHg of one another; thereafter, measurements were obtained every hour until end of case. A final measurement was taken after turning the patient supine and 5 minutes elapsed for equilibration.

Primary outcomes

Change in Intraoperative Ocular Pressure in Lumbar Spine Fusion Patients Head Raised 10 Degrees or Kept in Neutral Position

Time frame: Prone; 5 minutes after head raised to 10 degrees; every 15 minutes; 1 hr until end of surgery

The objective is to determine if slight elevation of the head (10 degrees up from neutral) can decrease the IOP compared to remaining in neutral position (standard of care) for the entire surgery. The mean values for Δ IOP measurements (i.e. two eye average maximum IOP - two eye average baseline IOP obtained at first prone measurement).

Secondary outcomes

Change and Correlations in Intraoperative Ocular Pressure in Lumbar Spine Fusion Patients

Time frame: prone; every 15 minutes; 1 hr until end of surgery

The secondary outcome is to evaluate factors (age, gender, duration of procedure, blood loss, intraoperative fluids, blood pressure, and carbon dioxide levels) looking for correlations with intraocular pressure changes.

Sponsors and collaborators

Lead sponsor

West Virginia University

Other

Registry information

Acronym: IOP

Important dates

Study start: 2008
Primary completion: 2014
Study completion: 2014
First posted: Jan 19, 2015
Registry last updated: Feb 24, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.