1. Perioperative Visual Loss
Kevin Driscoll
Matt Mitchell
Carolyn Srinivasan

2. Objectives Epidemiology Anatomy Physiology Pathophysiology Treatment
Prevention
Considerations

3. Vision Loss: Epidemiology & Anatomy

4. Vision Loss
Incidence of perioperative visual loss (POVL) after non-ocular surgery
0.002% of all surgeries (Newman, 2008)
0.2% of cardiac and spine surgeries (Newman, 2008)
Any portion of the visual pathway may be involved
Cornea to the occipital lobe
Optic nerve
Most common site of permanent injury
Presumed mechanism is ischemia
Anterior ischemic optic neuropathy (AION)
Cardiac surgery patients
Posterior ischemic optic neuropathy (PION)
Spine and neck procedures.
Age 5 to 81 years

5. Vision Loss: Review of Literature
Roth S, et al. Eye injuries after nonocular surgery: a study of 60,965 anesthetics from 1988 to Anesthesiology 1996;85:1020 –1027.
University of Chicago ( )
60,965 patients undergoing non-ocular surgery
1 patient (0.002%) suffered non-corneal POVL
Warner ME, et al. The frequency of perioperative vision loss. Anesth Analg 2001;93:1417–1421.
Mayo Clinic, retrospective study, excluded cardiac surgeries
501,342 non-cardiac surgeries
4 patients (0.0008%) developed POVL for longer than 30 days
Nuttall GA, et al. Risk factors for ischemic optic neuropathy after cardiopulmonary bypass: a matched case/control study. Anesth Analg 2001;93:1410–1416.
Mayo Clinic, retrospective study
27,915 cardiopulmonary bypass (CABG) procedures
17 (0.06%) patients were identified with peri-operative ION

6. Vision Loss: Review of Literature
Stevens WR, et al. Ophthalmic complications after spinal surgery. Spine1997;22:1319 –1324.
3 centers ( )
3,450 spine surgeries
7 cases (0.2%) with visual loss (2 patients with occipital infarctions, 4 patients with ION, and 1 patient with a central retinal vein occlusion)
Roth S, et al. Postoperative visual loss: still no answers– yet. Anesthesiology 2001;95:575–577.
15 year study of nearly 225,000 surgeries
3 of 3,351 patients (0.09%) developed POVL after spinal surgery
50-fold higher rate compared with all other non-ocular procedures
Chang SH, et al. The incidence of vision loss due to perioperative ischemic optic neuropathy associated with Spine surgery: the Johns Hopkins Hospital Experience. Spine 2005;30:1299 –1302.
20 year retrospective review at Johns Hopkins Hospital
14,102 spine surgeries
ION was identified in four cases (0.028%)

7. ASA POVL Registry
In 1999, the ASA POVL Registry was established in response to concerns that POVL seemed to be increasing
Purpose:
Meaningful analysis
Identify risk factors
Develop preventive measures
The database consists of:
Voluntary, anonymously reported cases
Visual loss within seven days of non-ocular surgery
Standardized form that includes:
detailed demographic, historical, examination, and intraoperative information

8. ASA POVL Registry June 2005 - 131 cases of POVL reported
95 spine cases
12 cardiac cases
6 major vascular cases
5 orthopedic cases
13 miscellaneous cases
2006 ASA Interim Report – in-depth analysis of 93 cases of POVL associated with spine surgery
83 cases of ION
67% were PION
23% AION
10% unspecified ION
10 cases of central retinal artery occlusion
73% of all cases in the setting of spine surgery
Age range: 5 to 81 years
MALES predominated among the spine cases
82% had one pre-existing vascular risk factor
64% had an ASA physical status I or II (healthy)

9. Vision Loss: Anterior Segment
The cornea is the most commonly reported location of ocular injury during anesthesia
Corneal abrasions and or exposure
Usually NOT a cause of permanent visual loss

10. Vision Loss: Retina
Most common retinal cause of visual loss is central retinal artery occlusion (CRAO)
Due to systemic or local arterial embolism
Cardiac and other vascular surgeries
Prone position spine surgeries
external compression of the globe due to malposition of head
ASA POVL Registry
93 spine surgery cases with postoperative visual loss
10 patients had CRAO
all unilateral
7 (of the 10) had additional evidence of peri-ocular trauma, (ipsilateral decreased supraorbital sensation, ptosis, erythema, corneal abrasion, and ophthalmoplegia)

11. Vision Loss: Optic Nerve
Most common site of permanent injury to the visual pathways in the setting of general anesthesia for non-ocular surgery is the optic nerves
Most often presumed mechanism of injury in this location is ischemia
Pupillary reactions are abnormal
ION is the most frequent condition associated with permanent POVL
The most common surgical setting is spine surgery in the prone position
Anterior ION
Acute disk edema
Cardiac Surgery
Posterior ION
Acute fundoscopic appearance: normal
Spinal (Prone) and Radical Neck Surgeries
Incidence increasing

12. Vision Loss: Retrochiasmal Visual Pathways
Homonymous hemianopsia (unilateral) versus cortical visual impairment (bilateral)
Pupillary reactions are normal
Usually ischemic in origin - embolic cerebral infarction (posterior cerebral arteries)
Other mechanisms - neck trauma during intubation
Risk of stroke after general, noncardiac procedures is 0.08% to 0.7%
Resection of head and neck tumors and cardiac and vascular surgeries are associated with higher risks
Most peri-operative strokes are infarctions and are embolic in origin
Incidence of visual loss from retro-chiasmal infarction in the peri-operative period is unknown

13. Physiology and Pathophysiology

14. Review
We don’t see with our eyes but the interpreted visual signal to the cortex (occipital lobe).
Information is transmitted to the brain via the optic nerve.
Each of the optic nerves receives blood supply from branches of the ophthalmic artery within each eye socket. The optic disc has a unique blood supply (the posterior ciliary arteries).

15. A Closer look at the blood supply
Blood supply to the chorid is thru the opthalmic artery (1)
one branches becomes the central retinal artery(2).
2 branches which become the posterior ciliary arteries (3).
These are the main arteries indicated for peri-operative visual loss 3 2 3 1

16. Perioperative Vision loss
Corneal Damage
Central Retinal Artery Occlusion (CRAO)
Ischemic Optic Neuropathy (ION)
Defined by where the lesion occurs on the optic nerve:
Anterior ION
Posterior ION

17. Direct Corneal Damage
Most Common preventable reason for Unilateral Vision Loss

18. Central Retinal Artery Occlusion (CRAO)
Central Retinal Artery Occlusion (CRAO)
The neurons of the retina, like those in the rest of the nervous system, are extremely susceptible to hypoxia.
Central retinal artery occlusions may follow thrombosis of the retinal artery, as in atherosclerosis or giant cell arteritis, or emboli of various types. Intracellular edema, manifested by retinal pallor, is prominent, especially in the macula where the ganglion cells are most numerous.
The vacularized choroid beneath the center of the macula (foveola) stands out in sharp contrast as a prominent “cherry red spot”.

19. Central Retinal Artery Occlusion (CRAO)
Usually caused by external pressure on the globe (positioning)
Common findings are unilateral vision loss with signs of external periorbital swelling or ecchymosis.
Prone position causes increase in intraocular pressure. Coupled with malposition this insult may lead susceptible patient populations to vision loss.
Direct Compression has been implicate. Mimics an accelerated glaucoma. pressure from malposition or direct pressure on the globe is translated from the Optic disk to the Central Retinal Artery.

20. Ischemic Optic Neuropathy (ION)
Etiology is still unclear. But there is a decreased delivery of O2 to the optic nerve.
Procedural dependent factors associated with ION elicited from the ASA closed claims:
Anemia
Prolonged procedures (>6.5hrs)
Sustained blood loss (44.7% of EBV)
Combination of the above
ION is further defined by where the lesion occurs and findings on retinal exam.

21. Ischemic Optic Neuropathy (ION)
Anterior ION:
Occurs in watershed area of Posterior Ciliary Artery (2 branches)
Anterior Optic Nerve supplied by multiple sources
Located in or near optic disk visible on retinal exam as edema.

22. Ischemic Optic Neuropathy (ION)
Posterior ION:
Pial branches from Internal Carotid supply mid-orbital optic nerve
Pial branches are found with variable density and in an unusual T-shaped perpendicular fashion.
This arrangement is characteristic of a low pressure system
Lumbar operations high incidence (LION)

23. Contributing factors to ION
Hypotension
Hypovolemia
Hypoxemia
Hemodilution
Facial edema
Use of Vasopressors
Prone
Head down
Increase in venous pressure

24. Treatment & Prevention

25. Prevention is a good thing
Prevention starts with:
Understanding of etiology
Understanding of Pathophysiology
Understanding of Risk Factors
Understanding the modalities to truly prevent POVL
UTILIZING the modalities to treat POVL

26. How to appropriately prevent POVL
Understanding the risk factors
Procedure dependent risk factors
CABG, prone cases, neck, nose and sinus surgery,
Intra-operative events- large EBL, systemic Hypotension, long duration of procedure (>5 hrs), and anemia

27. How to appropriately prevent POVL
Understanding the risk factors
Patient dependent risk factors
Hypertension
Atherosclerosis
Tobacco use
Diabetes Mellitus
Morbid obesity

28. How to appropriately prevent POVL
Understanding the risk factors
Procedural issues related to decrease oxygen delivery to the optic nerve
large EBL, prolonged Hypotension(52%), anemia, OR (9.9hrs)
ASA POVL registry as of 2000 had 23 incidents of POVL
Prone spine cases most common position (57%)
CABG (22%)
Ischemic optic neuropathy was the chief diagnosis in 20/23 reported cases

29. ASA POVL Registry Patient dependent related risk factors
Variable All Cases (n=23)
Median Age (range) (24-73) years
Obesity (percent cases) (56 percent)
Hypertension (48 percent)
Diabetes Mellitus (22 percent)
Smoking History (52 percent)
Atherosclerosis (52 percent)
Lee, LA: Postoperative visual loss data gathered and analyzed. ASA Newsletter 64(9): 25-27, 2000.

30. ASA POVL Registry 2006 Variables n (% of 83 cases)
Mean age /- 14yrs
Obesity (53%)
Hypertension (41%)
Diabetes Mellitus (16%)
Smoking History (46%)
Atherosclerosis (CAD) (10%)
Cerebrovascular disease ( 4%)
Increased Cholesterol/Lipids (13%)
1 Coexesting diseases (82%)
Lee, L. et al. (2006). The American society of anesthesiologist postoperative visual loss registry. Anesthesiology. 105, Lee, L. et al. (2006). The American society of anesthesiologist postoperative visual loss registry. Anesthesiology. 105,

31. Considerations

32. Current recommendations from ASA Task Force on Peri-operative Blindness
Current recommendations for major spine surgery
Consider risk explanation in consenting process
Use arterial catheters to monitor BP, consider CVP monitoring with CVC
Use colloids along with Crystalloids for replacement of volume
Position Head of Bed so that it is EQUAL or ABOVE the level of the HEART.
Consider staging surgeries. (decrease anesthesia time)
Lee, L. (2008). Solutions to POVL mystery requires research. The Official Journal of the Anesthesia Patient Safety Foundation. 23(1), P.3

33. Prone position Related Devices

34. Anesthesia Related Prone Position Devices

35. Summary Remember the Etiology of POVL
Remember the Case/Anesthetic specific considerations of POVL
Remember the Patient specific considerations
APSF recommendations based on current literature to reduce the incidence of POVL

36. References
Baig M, Lubow M, Immesoete P, et al. Vision loss after spine surgery: review of the literature and recommendations. Neurosurgery Focus. 2007;
Chang SH, Miller NR. The incidence of vision loss due to perioperative ischemic optic neuropathy associated with Spine surgery: the Johns Hopkins Hospital Experience. Spine 2005;30:1299 –1302.
Hayreh, SS. Posterior ischemic optic neuropathy: clinical features, pathogenesis, and management. Eye. 2004; 18:
Lee, LA: Postoperative visual loss data gathered and analyzed. ASA Newsletter. 2000;64:25-27.
Lee, L. Solutions to POVL mystery requires research. The Official Journal of the Anesthesia Patient Safety Foundation. 2008;23:p.3.
Newman, NJ. Perioperative Visual Loss After Nonocular Surgeries. Am J Opthalmol 2008;145:4:
Nuttall GA, Garrity JA, Dearani JA, et al. Risk factors for ischemic optic neuropathy after cardiopulmonary bypass: a matched case/control study. Anesth Analg 2001;93:1410–1416.

37. References
Roth S, Barach P. Postoperative visual loss: still no answers– yet. Anesthesiology 2001;95:575–577.
Roth S, Thisted RA, Erickson JP, Black S, Schreider BD. Eye injuries after nonocular surgery: a study of 60,965 anesthetics from 1988 to Anesthesiology 1996;85:1020 –1027.
Stevens WR, Glazer PA, Kelley SD, Lietman TM, Bradford DS. Ophthalmic complications after spinal surgery. Spine1997;22:1319 –1324.
Warner ME, Warner MA, Garrity JA, et al. The frequency of perioperative vision loss. Anesth Analg 2001;93:1417–1421.