Introduction to Perioperative Visual Loss in Spine Care

Spinal surgery has advanced significantly over the last few decades, offering relief to countless patients with debilitating musculoskeletal and neurological conditions. However, despite these technical advancements, certain rare but devastating complications remain a major concern for both the surgical and anesthesia teams. One of the most feared complications is perioperative visual loss (POVL), an event that can lead to permanent disability and a profoundly diminished quality of life for the patient. Effective perioperative visual loss management requires a deep understanding of the physiological risks, a collaborative approach to patient care, and a transparent consent process. Recent research has highlighted that the perception of POVL risk varies significantly among the medical professionals involved in complex spine care. Specifically, a survey involving members of the Society of British Neurological Surgeons and the Neuroanaesthesia and Critical Care Society revealed distinct differences in how surgeons and anesthetists view the materiality and incidence of this condition. While both groups recognize the gravity of the complication, their approaches to discussing it with patients are not always aligned. Understanding these perspectives is essential for developing standardized protocols that ensure patient safety and autonomy. This article explores the current landscape of POVL in the context of spine surgery, examining the disparities in clinician views and the strategies necessary to mitigate these risks effectively in modern clinical practice.

Pathophysiology of Vision Loss in Prone Surgery

To appreciate the necessity of comprehensive perioperative visual loss management, one must first understand the complex pathophysiology behind this rare complication. POVL typically manifests in three primary forms: ischemic optic neuropathy (ION), central retinal artery occlusion (CRAO), and, less frequently, cortical blindness. In the context of prone spine surgery, ION is the most prevalent cause. Clinicians further categorize this into anterior ischemic optic neuropathy (AION) and posterior ischemic optic neuropathy (PION), with PION being specifically associated with long-duration procedures. The underlying mechanism often involves a combination of factors that compromise the blood supply to the optic nerve. During prone positioning, increased venous pressure and interstitial edema can lead to decreased perfusion pressure in the ocular microvasculature. Furthermore, systemic factors such as intraoperative hypotension, significant blood loss, and hemodilution from excessive crystalloid administration can exacerbate the vulnerability of the optic nerve. Unlike CRAO, which often results from direct pressure on the globe, ION is frequently a result of physiological stressors that occur during the operation. Consequently, clinicians must maintain a high level of vigilance, especially when managing high-risk patients who present with comorbidities like obesity, hypertension, or peripheral vascular disease. Because there are no proven effective treatments for established ION, the focus remains strictly on prevention and the early identification of patients who are at an elevated risk of developing these life-altering visual deficits.

Disparities in Risk Perception and Materiality

A recent study led by Pitsika and colleagues has shed light on the significant discrepancies in risk perception between surgeons and anesthetists regarding POVL. According to their survey results, only about 58% of surgeons considered POVL to be a material risk that must be disclosed to every patient. In contrast, nearly 80% of anesthetists viewed the risk as material. This disparity is particularly striking when considering the potential for litigation and the ethical imperative of informed consent in modern medicine. Furthermore, the estimated incidence of POVL varied widely between the two groups. Anesthetists generally estimated the incidence to be higher, ranging from 0.03% to 0.2%, whereas over half of the surgeons estimated it to be much lower, between 0.0001% and 0.004%. These differing views likely reflect the different roles these specialists play during the perioperative period. Anesthetists are primarily responsible for the physiological stability of the patient, including the management of blood pressure and fluid balance, which are critical factors in the development of POVL. On the other hand, surgeons are focused on the technical and mechanical aspects of the spinal procedure. Despite these differences, most clinicians who had personally managed a patient with POVL reported that the experience led to a profound change in their clinical practice. This suggests that while the complication is rare, its impact on the medical community is substantial and long-lasting.

Implementing Perioperative Visual Loss Management Through Informed Consent

The consent process is a cornerstone of ethical medical practice, particularly when discussing rare but catastrophic risks. In the study by Pitsika et al., a vast majority of both surgeons and anesthetists agreed that the outpatient or pre-assessment clinic is the optimal setting for discussing the risk of POVL. Specifically, 81% of surgeons and 93% of anesthetists felt that these conversations should occur well before the day of surgery. This timing allows patients to process the information without the immediate stress of the impending procedure. Moreover, about 75% of anesthetists believed that both specialists should be involved in the discussion. This collaborative approach ensures that the patient receives a consistent message regarding both the surgical and anesthetic risks. However, despite these views, the survey indicated that a significant number of clinicians still do not routinely discuss POVL. The decision to disclose a rare risk often depends on the clinician's interpretation of materiality—whether a reasonable person in the patient's position would want to know about the risk. Given the permanent nature of visual loss, many experts argue that it should always be considered a material risk for any high-risk spine procedure. Standardizing the consent process through institutional guidelines could help bridge the gap between current practice and the ideal collaborative model, ultimately enhancing patient autonomy and professional transparency.

Intraoperative Mitigation Strategies and Patient Positioning

Effective perioperative visual loss management depends heavily on the implementation of intraoperative mitigation strategies. Since prolonged surgery in the prone position is a primary risk factor, clinicians should strive to minimize operative time whenever possible. When long procedures are necessary, specific attention must be paid to patient positioning. Using specialized frames, such as the Jackson table, can help maintain the head in a neutral position, ideally at or above the level of the heart, to reduce venous congestion in the head and neck. Additionally, avoiding direct pressure on the eyes is paramount to preventing CRAO. From an anesthetic perspective, maintaining hemodynamic stability is crucial. This includes avoiding prolonged periods of hypotension and managing blood loss aggressively to prevent severe anemia. Some guidelines suggest using a higher proportion of colloids rather than crystalloids for fluid replacement to minimize interstitial edema. Monitoring intraocular pressure is another area of interest, although it is not yet a standard practice in most centers. Notably, periodic checks of the patient's head position throughout the surgery can ensure that no accidental pressure is being applied to the globe. By integrating these technical and physiological safeguards, the surgical team can significantly reduce the likelihood of this devastating complication, even in the most complex spinal cases where the inherent risks are significantly elevated.

Collaborative Approaches and National Guidelines

The findings from recent surveys emphasize the urgent need for national guidance from professional societies such as the SBNS, BASS, and NACCS. Standardized guidelines would provide a clear framework for clinicians, encouraging the routine discussion of POVL during the consent process and outlining best practices for intraoperative management. Furthermore, the survey indicated that nearly 20% of surgeons and 24% of anesthetists intended to change their practice based on the shared data. This reflects a growing awareness of the importance of addressing rare complications head-on. Future research should focus on refining risk stratification models to identify which patients are most susceptible to optic nerve ischemia. For instance, incorporating patient-specific vascular profiles into preoperative assessments could help clinicians tailor their management strategies more effectively. Additionally, the development of electronic decision-support tools could remind clinicians to initiate the POVL consent process in the outpatient setting. As the medical community continues to evolve, the emphasis must remain on interdisciplinary collaboration. By working together, surgeons and anesthetists can ensure that patients are not only well-informed but also protected by the highest standards of perioperative care. Ultimately, the goal is to transform POVL from a feared uncertainty into a managed risk, through transparency, education, and clinical excellence across all specialties involved in spine care.

Frequently Asked Questions

What are the primary risk factors for perioperative visual loss in spine surgery?

The primary risk factors include prolonged surgical duration in the prone position, significant intraoperative blood loss, and hypotension. Patient-specific factors such as obesity, male sex, and pre-existing vascular diseases like hypertension or diabetes also increase susceptibility. Maintaining head elevation and minimizing operative time are key strategies for reducing these risks during complex procedures.

Which specialty is responsible for discussing POVL risk with the patient?

While practice varies, a collaborative approach is recommended. Most anesthetists believe both the surgeon and the anesthetist should discuss the risk. This ensures the patient understands both the physiological and technical risks involved. Clear communication between both specialists helps provide a consistent and thorough explanation of this rare but material risk.

When is the best time to obtain consent for the risk of POVL?

Expert consensus suggests that the best time for these discussions is during outpatient or pre-assessment clinics, rather than on the day of surgery. Discussing the risk early allows patients to consider the information carefully without the pressure of an imminent operation, which supports the ethical principle of informed consent and patient autonomy.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or establish a doctor-patient relationship. Clinicians should rely on their professional judgment and refer to the latest local and national guidelines for clinical practice.

References

Pitsika M et al. [object Object] Br J Neurosurg. 2025 Aug. doi: 10.1080/02688697.2023.2275621. PMID: 37943103.

Lee LA, Roth S, Posner KL, et al. The American Society of Anesthesiologists Postoperative Visual Loss Registry: analysis of 93 spine surgery cases with postoperative visual loss. Anesthesiology. 2006;105(4):652-659.

American Society of Anesthesiologists Task Force on Perioperative Visual Loss. Practice advisory for perioperative visual loss associated with spine surgery: an updated report. Anesthesiology. 2019;130(1):12-30.