Retinal artery occlusion (RAO) is a rare but devastating complication of spinal fusion surgery. We aimed to determine its incidence and associated risk factors.Methods:
Hospitalizations involving spinal fusion surgery were identified by searching the National Inpatient Sample, a database of hospital discharges, from 1998 to 2013. RAO cases were identified using ICD-9-CM codes. Using the STROBE guidelines, postulated risk factors were chosen based on literature review and identified using ICD-9-CM codes. Multivariate logistic models with RAO as outcome, and risk factors, race, age, admission, and surgery type evaluated associations.Results:
Of an estimated 4,784,275 spine fusions in the United States from 1998 to 2013, there were 363 (CI: 291–460) instances of RAO (0.76/10,000 spine fusions, CI: 0.61–0.96). Incidence ranged from 0.35/10,000 (CI: 0.11–1.73) in 2001–2002 to 1.29 (CI: 0.85–2.08) in 2012–2013, with no significant trend over time (P = 0.39). Most strongly associated with RAO were stroke, unidentified type (odds ratio, OR: 14.33, CI: 4.54–45.28, P < 0.001), diabetic retinopathy (DR) (OR: 7.00, CI: 1.18–41.66, P = 0.032), carotid stenosis (OR: 4.94, CI: 1.22–19.94, P = 0.025), aging (OR for age 71–80 years vs 41–50 years referent: 4.07, CI: 1.69–10.84, P = 0.002), and hyperlipidemia (OR: 2.96, CI: 1.85–4.73, P < 0.001). There was an association between RAO and transforaminal lumbar interbody fusion (OR: 2.95, CI: 1.29–6.75, P = 0.010). RAO was more likely to occur with spinal surgery performed urgently or emergently compared with being done electively (OR: 0.40, CI: 0.23–0.68, P < 0.001).Conclusions:
Patient-specific associations with RAO in spinal fusion include aging, carotid stenosis, DR, hyperlipidemia, stroke, and specific types of surgery. DR may serve as an observable biomarker of heightened risk of RAO in patients undergoing spine fusion.