Blindness
Conditions
Keywords
blindness, ischemic optic neuropathy
Brief summary
This is a study to focus on the feasibility of using a monitor which may signal loss of visual function intraoperatively.
Detailed description
The degree of a relative afferent pupillary defect (RAPD) has been correlated with the severity of an eye injury and has been shown to have prognostic significance as an indicator of retinal ischemia. Therefore light flashed evoked pupillometry (LFEP) may serve as a useful indicator of visual function. LFEP's are not known to be sensitive to anesthetics. We will measure LFEP's using different anesthetic techniques to see if there are measurable differences in the latency, amplitude and constriction velocity of the pupillary reflex. Prior to induction of anesthesia, pupillometer readings will be taken in the supine position in both eyes. The patient will be anesthetised using a standard induction technique. For maintenance of anesthesia a remifentanil infusion will be administered and supplemented by either propofol infusion (at 120 and 160 mcg/kg/min)or sevoflurane (at 1.5 and 2.5% end-tidal in random sequence. The patients will receive muscle relaxants as needed. Pupillometry readings will be taken in both eyes after induction, after steady maintenance has been achieved and every 10 minutes for 30 minutes at each drug dose.
Interventions
DRUGpropofol
Propofol infusion 120 and 160 mcg/kg/min in random sequence during the operative procedure
DRUGSevoflurane
sevoflurane 1.5% and 2.5% end tidal in random sequence
Sponsors
Rutgers, The State University of New Jersey
Study design
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* planned orthopedic surgery on the lower extremities and positioned on the back
Exclusion criteria
* recent bout of conjunctivitis or pink eye * condition which inhibits the normal pupillary function of my eye
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Measure the pupil response using different anesthetic techniques | pupillometry measurements will be taken in both eyes after induction of anesthesia |
Secondary
| Measure | Time frame |
|---|---|
| Measure the pupil response using different anesthetic techniques | When steady maintenance of anesthesia drug is obtained measure pupillometry response at 10 min |
| Measure the pupil response using different anesthetic technique | When steady maintenance of anesthesia drug is obtained measure pu[illometry response at 30 minutes. |
Countries
United States
Outcome results
None listed