Postoperative Visual Postoperative Visual LossLoss

Marybeth A. Grazko MDMarybeth A. Grazko MD

Postoperative Visual LossPostoperative Visual Loss

Impairment or total loss of sight Impairment or total loss of sight following an otherwise uncomplicated following an otherwise uncomplicated surgical anesthetic requiring surgical anesthetic requiring procedure (non-ocular)procedure (non-ocular)

Most commonly associated with spinal Most commonly associated with spinal surgeries.surgeries.

Most common pathophysiology is Most common pathophysiology is posterior ischemic optic neuropathy posterior ischemic optic neuropathy (PION).(PION).

Postoperative Visual LossPostoperative Visual Loss Uncommon,devastating and poorly understood.Uncommon,devastating and poorly understood. UncommonUncommon

– Most often associated with spinal, cardiac, head and Most often associated with spinal, cardiac, head and neck surgeries. Incidence is spine surgery 0.2% (50 neck surgeries. Incidence is spine surgery 0.2% (50 fold higher incidence ) fold higher incidence )

– Posterior ischemic optic neuropathy is by far the most Posterior ischemic optic neuropathy is by far the most common mechanism of permanent visual loss common mechanism of permanent visual loss

– 83/93 cases reported in American Spine Association 83/93 cases reported in American Spine Association registry were due to ischemic optic neuropathy registry were due to ischemic optic neuropathy (ION),(ION),

– 53 P(posterior)ION, 19 A(anterior)ION, 10 53 P(posterior)ION, 19 A(anterior)ION, 10 unspecified ION, 10 central retinal artery occlusionunspecified ION, 10 central retinal artery occlusion

Case 1Case 1

65 year old male underwent65 year old male underwent– Cystocopy, bilateral ureteral stent Cystocopy, bilateral ureteral stent

placementplacement– Laparascopic bilateral pelvic lymph node Laparascopic bilateral pelvic lymph node

dissectiondissection– Laparscopic radical prostatectomyLaparscopic radical prostatectomy– 16.5 hour procedure16.5 hour procedure– Trendelenburg dorso-lithotomy position Trendelenburg dorso-lithotomy position

for most of this timefor most of this time

Pre-Op HistoryPre-Op History

Past Ocular hxPast Ocular hx– Retinal detachment repairRetinal detachment repair– CataractCataract– Primary open angle glaucoma OS with Primary open angle glaucoma OS with

glaucomatous optic neuropathy (had afferent glaucomatous optic neuropathy (had afferent pupillaryt defect OS pre-operatively)pupillaryt defect OS pre-operatively)

– Humphrey 30-2 perimetry pre-operatively Humphrey 30-2 perimetry pre-operatively showed:showed: Normal ODNormal OD Arcuate defect OSArcuate defect OS

– pre-operative visual acuity of 20/20 OD, 20/50 OSpre-operative visual acuity of 20/20 OD, 20/50 OS

Intra-operative CourseIntra-operative Course

After anesthetic induction blood After anesthetic induction blood pressure dropped to pressure dropped to 80/50 80/50 for 30 for 30 minutes but otherwise maintained minutes but otherwise maintained 110-130 mmHg systolic and 70-80 110-130 mmHg systolic and 70-80 mm Hg for the rest of the casemm Hg for the rest of the case

Blood loss 500ccBlood loss 500cc Post op HCT was 38.3Post op HCT was 38.3 No known operative or anesthetic No known operative or anesthetic

complicationscomplications

Post Op examPost Op exam

Patient complained of visual loss OD upon Patient complained of visual loss OD upon awakeningawakening

Visual acuity 20/40 OD, 20/60 OS; no Visual acuity 20/40 OD, 20/60 OS; no afferent pupil defect!afferent pupil defect!

Mild punctate corneal erosions ODMild punctate corneal erosions OD Significant facial and periorbital edemaSignificant facial and periorbital edema Dilated fundus exam was normalDilated fundus exam was normal Humphrey perimetry: OD peripheral Humphrey perimetry: OD peripheral

depression extending to fixation superiorly. depression extending to fixation superiorly. OS unchangedOS unchanged

Case 2Case 2

22 year old female22 year old female Right laparoscopic pyeloplasty for right Right laparoscopic pyeloplasty for right

ureteropelvic junction obstructionureteropelvic junction obstruction 6 hour surgery6 hour surgery Blood pressure 100/45 after induction, 100-Blood pressure 100/45 after induction, 100-

110 over 50-60 mm Hg for duration of the 110 over 50-60 mm Hg for duration of the casecase

Blood loss 50 ccBlood loss 50 cc Post op HCT 34.2Post op HCT 34.2 Significant facial and periorbital edemaSignificant facial and periorbital edema

Post Operative statusPost Operative status

Immediately noted bilateral loss of Immediately noted bilateral loss of vision but attributed it to the anesthesiavision but attributed it to the anesthesia

Post-Op Day 7 Ophthalmology consult:Post-Op Day 7 Ophthalmology consult: Visual acuity 20/20 OUVisual acuity 20/20 OU Relative afferent pupil defect OSRelative afferent pupil defect OS Humphrey perimetry: peripheral Humphrey perimetry: peripheral

depression OD, diffuse depression OSdepression OD, diffuse depression OS Brain and orbit MRI were normalBrain and orbit MRI were normal

Post Operative Visual LossPost Operative Visual Loss

Primary pathophysiologyPrimary pathophysiology– Anterior ischemic optic neuropathyAnterior ischemic optic neuropathy– Posterior ischemic optic neuropathyPosterior ischemic optic neuropathy– Central retinal artery occlusionCentral retinal artery occlusion

Associated surgical proceduresAssociated surgical procedures– Cardiac, thoracic, cerebrovascular, Cardiac, thoracic, cerebrovascular,

abdominal, orthopedic, sinus and neckabdominal, orthopedic, sinus and neck– Majority of the cases are associated with Majority of the cases are associated with

spinal surgeriesspinal surgeries

Majority of perioperative visual Majority of perioperative visual loss has been due to PION (50-loss has been due to PION (50-

71%)71%) Posterior Ischemic Optic NeuropathyPosterior Ischemic Optic Neuropathy

– Sudden painless loss of visionSudden painless loss of vision– Unilateral or bilateral (may or may not have Unilateral or bilateral (may or may not have

associated afferent pupillary defect)associated afferent pupillary defect)– Normal fundus examNormal fundus exam– Nonspecific visual field abnormalityNonspecific visual field abnormality– In the absence of an afferent pupil defect may In the absence of an afferent pupil defect may

need negative neuroimaging to confirm the need negative neuroimaging to confirm the diagnosisdiagnosis

Delay in DiagnosisDelay in Diagnosis

Often most of the bedside objective Often most of the bedside objective exam will be normal.exam will be normal.

Patients often may attribute changes Patients often may attribute changes in their vision to a recovery time in their vision to a recovery time following anesthesia.following anesthesia.

May have other post-operative issues May have other post-operative issues that overshadow these symptoms.that overshadow these symptoms.

Clinical Characteristics of Clinical Characteristics of PatientsPatients

Buono MB, Forrozan R, Surv Ophthalmol 50: 15-26, 2005Buono MB, Forrozan R, Surv Ophthalmol 50: 15-26, 2005Lee et al, Anesthesiology 2006; 105: 652-9Lee et al, Anesthesiology 2006; 105: 652-9

AgeAge– 51.9 average51.9 average– 43.9 spinal surgery, 43.9 spinal surgery, registry average was 50registry average was 50

Degree of visual lossDegree of visual loss– Count fingers or worse in 75.8%Count fingers or worse in 75.8%– No light perception in 53.8% No light perception in 53.8% (56.6%)(56.6%)– Bilateral involvement in 60.9% Bilateral involvement in 60.9% (66%)(66%)

Visual recoveryVisual recovery– Some visual recovery in 37.9% Some visual recovery in 37.9% (42%)(42%)– Patients with poorer vision initially tended to Patients with poorer vision initially tended to

have less improvement and poorer outcomeshave less improvement and poorer outcomes– 54.9% had a final visual acuity of Hand motion or 54.9% had a final visual acuity of Hand motion or

worseworse

Clinical Characteristics of Clinical Characteristics of PatientsPatients

Buono MB, Forrozan R, Surv Ophthalmol 50: 15-26, 2005Buono MB, Forrozan R, Surv Ophthalmol 50: 15-26, 2005

No optic disc cupping noted No optic disc cupping noted Small congenital optic nerve head or Small congenital optic nerve head or

absent phyiologic cupping noted only absent phyiologic cupping noted only in 4% in one seriesin 4% in one series

65.5% had one or more vascular risk 65.5% had one or more vascular risk factorsfactors

34.5% had no vascular risk factors34.5% had no vascular risk factors

Clinical CharacteristicsClinical CharacteristicsLee et al, Anesthesiology 2006; 105: 652-9Lee et al, Anesthesiology 2006; 105: 652-9

Average anesthetic durationAverage anesthetic duration– 9.8 h +/- 3.1 hours9.8 h +/- 3.1 hours– 6 hours or longer in 94%6 hours or longer in 94%

Estimated blood lossEstimated blood loss– 82% was 1000 cc or greater82% was 1000 cc or greater

Blood Pressure widely varied from less Blood Pressure widely varied from less than 20% of baseline to 50% of than 20% of baseline to 50% of baseline or greater, HCT (hematocrit) baseline or greater, HCT (hematocrit) also had wide variations between also had wide variations between patientspatients

PathologyPathology

PION results from infarction of the PION results from infarction of the intraorbital portion of the optic nerveintraorbital portion of the optic nerve

Infarction results due to decreased Infarction results due to decreased oxygen delivery presumably to any oxygen delivery presumably to any number of perioperative number of perioperative hemodynamic derrangementshemodynamic derrangements

PathophysiologyPathophysiologyDecreased oxygenation leading to Decreased oxygenation leading to

infarctioninfarction Decrease in perfusion pressureDecrease in perfusion pressure

– Hypotension (decreased Mean Arterial Pressure)Hypotension (decreased Mean Arterial Pressure)– Disturbed autoregulation (atherosclerosis, Disturbed autoregulation (atherosclerosis,

hypertension)hypertension)– Increase in intraocular pressure ( prone and head Increase in intraocular pressure ( prone and head

down positioning)down positioning)– Increase in Venous pressureIncrease in Venous pressure

Prolonged head down and prone positionProlonged head down and prone position Internal jugular compression or ligationInternal jugular compression or ligation

Decreased oxygen carrying abilityDecreased oxygen carrying ability– AnemiaAnemia– HemodilutionHemodilution

Hemodynamic Hemodynamic derangementsderangements

– Hypotension and blood loss are common in Hypotension and blood loss are common in cardiac bypass surgery. Low incidence of PVL cardiac bypass surgery. Low incidence of PVL seen in cardiac bypass patients suggests that seen in cardiac bypass patients suggests that another mechanism is playing an additional role another mechanism is playing an additional role in the mechanism for permanent visual loss.in the mechanism for permanent visual loss.

– Anatomic variation in blood supply of intraorbital Anatomic variation in blood supply of intraorbital nerve (absent anastomoses)nerve (absent anastomoses)

– Positioning creating either increased intraocular Positioning creating either increased intraocular pressure and/or increased orbital venous pressure and/or increased orbital venous pressurepressure

From: Ozcan : Anesth Analg, Volume 99 (4), Oct 2004. 1152-1158

Blood Supply of the NerveBlood Supply of the Nerve

Facial EdemaFacial Edema

Facial edemaFacial edema– Often data was not provided but in 19 patients Often data was not provided but in 19 patients

where this was commented upon, 17/19 had where this was commented upon, 17/19 had post operative facial edema and in 11 was post operative facial edema and in 11 was considered to be severe. (both of our cases had considered to be severe. (both of our cases had severe facial edema)severe facial edema)

Evidence that positioning can increase Evidence that positioning can increase intraocular pressure (maximal in intraocular pressure (maximal in Trendelenberg)Trendelenberg)

Increased intraocular pressure can lead to Increased intraocular pressure can lead to decreased perfusion.decreased perfusion.

PathogenesisPathogenesis

Hemodynamic derangementHemodynamic derangement– Evidence to date points to prolonged surgery, Evidence to date points to prolonged surgery,

blood loss or combination of bothblood loss or combination of both In a patient with a specific In a patient with a specific

susceptibilitysusceptibility which at this point remains which at this point remains unclearunclear– Incomplete anastomoses, altered anatomyIncomplete anastomoses, altered anatomy

Risks factors of positioning and Risks factors of positioning and periorbital/facial edema may contribute periorbital/facial edema may contribute but at this point are less clearly factorsbut at this point are less clearly factors

Recent Practice AdvisoryRecent Practice AdvisoryAm Soc of AnesthesiologistsAm Soc of Anesthesiologists

Spine procedureSpine procedure Positioned pronePositioned prone Receiving general anesthesiaReceiving general anesthesia Uncommon occurrenceUncommon occurrence

– Less than 0.2% of spine surgeriesLess than 0.2% of spine surgeries– Makes it a difficult thing to study, mostly Makes it a difficult thing to study, mostly

case control studies and case reports in case control studies and case reports in terms of what is in the literature.terms of what is in the literature.

ASA Practice AdvisoryASA Practice Advisory Task force of 12 membersTask force of 12 members

– 4 Anesthesiologists4 Anesthesiologists– 3 Neuro-Ophthalmologists3 Neuro-Ophthalmologists– 1 Orthopedic Spine Surgeon1 Orthopedic Spine Surgeon– 1 Neurosurgeon1 Neurosurgeon– 2 Methodologists from ASA Practice Parameters committee2 Methodologists from ASA Practice Parameters committee– 3 physicians served as liasons from national organizations3 physicians served as liasons from national organizations

NANOSNANOS Am Academy of Orthopedic SurgeonsAm Academy of Orthopedic Surgeons Am Association of Neurologic SurgeonsAm Association of Neurologic Surgeons

Opinions were also solicited from Society for Neurosurgical Opinions were also solicited from Society for Neurosurgical Anesthesia and Critical Care, NANOS, and North American Anesthesia and Critical Care, NANOS, and North American Spine SocietySpine Society

Summary of the available literature, expert opinion, open Summary of the available literature, expert opinion, open forum commentary and consensus surveysforum commentary and consensus surveys

Predictive Risk FactorsPredictive Risk Factors

Vascular risk factors (hypertension, Vascular risk factors (hypertension, diabetes, smoking,obesity,glaucoma, diabetes, smoking,obesity,glaucoma, carotid artery disease)carotid artery disease)

Pre-operative presence of anemiaPre-operative presence of anemia Prolonged procedures (range was 2-Prolonged procedures (range was 2-

12 with average of 6.5 hours)12 with average of 6.5 hours) Substantial blood loss (ranges was Substantial blood loss (ranges was

10-200% with average of 44.7% of 10-200% with average of 44.7% of total blood volume)total blood volume)

Pre-Operative AssessmentPre-Operative Assessment

Task Force was in consensus thatTask Force was in consensus that– There is no evidence that an ophthalmic There is no evidence that an ophthalmic

or neuro-ophthalmic exam pre-operatively or neuro-ophthalmic exam pre-operatively is useful for identifying patients at riskis useful for identifying patients at risk

– Recommendation was to consider Recommendation was to consider informing patients in whom prolonged informing patients in whom prolonged procedures, substantial blood loss or both procedures, substantial blood loss or both are anticipated that there is a small are anticipated that there is a small unpredictable risk of perioperative visual unpredictable risk of perioperative visual loss. loss.

BP,fluid,blood loss BP,fluid,blood loss managmentmanagment

Recommend continual monitoring in Recommend continual monitoring in high risk patients (CVP monitoring)high risk patients (CVP monitoring)

Deliberate hypotensive techniques Deliberate hypotensive techniques have not been shown to be associated have not been shown to be associated with peri-operative visual loss.with peri-operative visual loss.

There is no absolute hematocrit There is no absolute hematocrit number to use a transfusion number to use a transfusion threshold, individually dependentthreshold, individually dependent

Patient PositioningPatient Positioning

Several case reports of direct pressure to Several case reports of direct pressure to the eyes from use of a sheet roll or head the eyes from use of a sheet roll or head rest resulting in central retinal artery rest resulting in central retinal artery occlusion (CRAO) or ION but also in occlusion (CRAO) or ION but also in patients with no headrest (head held by patients with no headrest (head held by pins)pins)

All task force members agreed that direct All task force members agreed that direct pressure on the eye should be avoided to pressure on the eye should be avoided to reduce risk of CRAO and other ocular reduce risk of CRAO and other ocular damage.damage.

Head positioning?Head positioning?

No pathophysiologic mechanism by which facial No pathophysiologic mechanism by which facial edema can cause perioperative IONedema can cause perioperative ION

Eyes of prone patients should be regularly checkedEyes of prone patients should be regularly checked Peri-operative facial edema is common in high risk Peri-operative facial edema is common in high risk

patientspatients Postion the head level or higher than the heart for Postion the head level or higher than the heart for

high-risk patientshigh-risk patients Keep the head in a neutral forward position when Keep the head in a neutral forward position when

possiblepossible Direct pressure on the eye should be avoided to Direct pressure on the eye should be avoided to

avoidavoid CRAO CRAO

TreatmentTreatment

Correction of hemodynamic Correction of hemodynamic derangements, systemic steroids, derangements, systemic steroids, antiplatelet therapy, measures to antiplatelet therapy, measures to lower intraocular pressure or lower intraocular pressure or intracranial pressure.intracranial pressure.

None effective though a few case None effective though a few case reports of improvement with reports of improvement with transfusion and keeping blood transfusion and keeping blood pressure over 140/80pressure over 140/80

Peri-operative Visual loss Peri-operative Visual loss registryregistry

http://depts.washington.edu/asaccp/ehttp://depts.washington.edu/asaccp/eye/index.shtmlye/index.shtml

www.asaclosedclaims.orgwww.asaclosedclaims.org– Established in 1999Established in 1999– Recently published on 93 spine cases Recently published on 93 spine cases

(93/131 cases 72%)(93/131 cases 72%)– Lee et al Anesthesiology 2006, 205:652-Lee et al Anesthesiology 2006, 205:652-

659.659.– Anonymous reportingAnonymous reporting

AdvisoryAdvisory

PION can be seen with a variety of PION can be seen with a variety of surgical procedures but is more likely surgical procedures but is more likely to be seen with spinal proceduresto be seen with spinal procedures

There is no evidence that There is no evidence that compression is a factor in the compression is a factor in the pathophysiology of this entity pathophysiology of this entity although compression is clearly although compression is clearly related to CRAOrelated to CRAO

PION does correlate with prolonged PION does correlate with prolonged surgery (> 6 hours)surgery (> 6 hours)

AdvisoryAdvisory

While PION does correlate with blood While PION does correlate with blood loss, the amount of blood loss loss, the amount of blood loss required is unclear and can still occur required is unclear and can still occur in the absence of significant blood in the absence of significant blood loss as our cases demonstrate.loss as our cases demonstrate.

PION is somewhat more likely with PION is somewhat more likely with prolonged hypotension but again the prolonged hypotension but again the range where this is significant is range where this is significant is likely to be very patient dependant.likely to be very patient dependant.

AdvisoryAdvisory

Patients in a prolonged supine Patients in a prolonged supine position with significant peri-orbital position with significant peri-orbital swelling (our two cases) while swelling (our two cases) while theoretically this could predispose theoretically this could predispose them to PION has yet to be them to PION has yet to be recognized as an independent risk recognized as an independent risk factor.factor.

PrognosisPrognosis

Visual recoveryVisual recovery– Some visual recovery in 37.9% Some visual recovery in 37.9% (42%)(42%)– Patients with poorer vision initially tended to Patients with poorer vision initially tended to

have less improvement and poorer outcomeshave less improvement and poorer outcomes– 54.9% had a final visual acuity of HM or worse54.9% had a final visual acuity of HM or worse

Both of our patients had some Both of our patients had some improvement both in their acuity and visual improvement both in their acuity and visual fields but again were more mildly affected fields but again were more mildly affected than many of the other reported casesthan many of the other reported cases

SummarySummary

Postoperative Visual Loss is a Postoperative Visual Loss is a fortunately rare but devastating fortunately rare but devastating condition that is still poorly understood.condition that is still poorly understood.

Recent reports by the ASA Registry and Recent reports by the ASA Registry and reviews of the literature would suggest reviews of the literature would suggest counseling patients who are counseling patients who are undergoing procedures that are undergoing procedures that are prolonged and/or with expected prolonged and/or with expected substantial blood loss about the substantial blood loss about the potential risk for this condition.potential risk for this condition.