Intraoperative Ocular Pressure in Lumbar Spine Fusion Patients
Condition: Raised Ocular Pressure
Study type: Interventional

Summary: 
      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.
    

Detailed description: 
      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.
    

Intervention name(s): Head raised 10 degrees; Head in neutral position
Intervention type(s): Procedure; Procedure
Intervention description(s): 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.; 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.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Keywords: Intraoperative ocular pressure