Avoid Globe Compression: Replacement of the horseshoe headrest with Mayfield pins, tongs, or T-pillows can reduce the risk of central retinal artery occlusion by preventing direct eye pressure.
Positioning: Use the Jackson table to ensure the head is level or slightly elevated to reduce venous congestion and avoid excessive head-down positioning.
Eye Protection: Use tape or ointment to keep the patient’s eyes closed during surgery and prevent corneal abrasions. Avoid external pressure on the eyes to reduce the risk of central retinal artery occlusion.
Hemodynamics Optimization and Blood Loss Management: Maintain a mean arterial pressure (MAP) above 70 mmHg to ensure adequate oxygen delivery. Transfusion should be considered when hemoglobin levels drop below 8-9 g/dL, particularly in older patients or those with comorbidities. Cell salvage and the appropriate blood transfusion help maintain hemodynamic stability. Intraoperative administration of antifibrinolytics, such as tranexamic acid (TXA), can further reduce bleeding.
Monitoring and Resuscitation: Monitoring central venous pressure, performing regular hematocrit checks, and using colloids and crystalloids to maintain euvolemia can reduce the likelihood of optic nerve ischemia. Some evidence suggests that using colloids (e.g., albumin) may help prevent tissue edema, including in the optic nerve, during long surgeries, although this remains a debated strategy.
Preoperative Planning: High-risk patients (e.g., those with significant vascular disease, diabetes, or undergoing long spinal surgeries) should be identified. Preventative strategies include maintaining adequate intraoperative blood pressure, minimizing anemia, and considering staged surgeries for complex, long procedures should be taken.
Preoperative Ophthalmologic Screening: Patients with known glaucoma or suspected glaucoma should undergo a thorough ophthalmologic evaluation preoperatively by an ophthalmologist to determine whether prophylactic treatment (e.g., intraocular pressure-lowering medications) is necessary before surgery, such as in cases of acute angle closure glaucoma.
Postoperative Ophthalmologic Consultation: consultation with ophthalmology for any postoperative visual disturbances can improve outcomes, although vision loss may be irreversible in many cases.
Minimize the Surgery Time: To reduce the risk of optic nerve ischemia, procedures should be staged or shorter. Prolonged surgeries, especially in the prone position, have shown a higher incidence of visual loss.
Avoiding Vasoconstrictors: Catecholamines should be minimized to prevent vasoconstriction, which can impair ocular perfusion.
| Parameter | Value | Why it matters |
|---|---|---|
| Mean arterial pressure | Above 70 mmHg | Recommended in prolonged surgeries to ensure adequate oxygen delivery and prevent optic nerve ischemia |
| Transfusion threshold | Hemoglobin below 8–9 g/dL | Consider transfusion, particularly in older patients or those with comorbidities |
| Surgical duration | Longer than 6 hours | Significant increase in POVL incidence; consider staging long procedures |
| Blood loss | More than 1 liter | Increases ischemic conditions and reduces oxygen delivery to the optic nerve |
| Core temperature | Below 35°C | Hypothermia is associated with impaired perfusion and increased ischemic risk |
| Head elevation (prone) | 10° | Reduces intraocular pressure; keep the head level or slightly elevated to limit venous congestion |
| Patient age | Over 50 | May have age-related loss of optic nerve fibers; more prone to vascular conditions |
