Oculocardiac reflex in ophthalmic practice: a systematic review and meta-analysis

Background: The oculocardiac reflex (OCR) is a trigeminovagal reflex that is very common during eye surgeries and in particular when the extraocular muscles are manipulated. Usually, the OCR vanishes on its own; however, it can result in serious cases of bradycardia and other cardiac problems if it happens, for instance, in children. Several research works have recorded various degrees of frequency and intensity of OCR, but it is still quite unclear how anesthesia, surgical and preventive factors contribute to it.

Objective: To systematically review and quantitatively synthesize available evidence on the incidence, severity, and modifying factors of the oculocardiac reflex in ophthalmic practice.

Methods: We conducted a systematic review and meta, analysis following the PRISMA guidelines based on pre, established criteria. Eight key studies that assessed OCR in ophthalmic surgical and examination environments were incorporated in the review, covering pediatric, adult, and neonatal populations. Data regarding OCR incidence, severity, anesthetic agents, procedural factors, and preventive interventions were collected. A random, effects meta, analysis was carried out to calculate the combined incidence, and comparative analyses were conducted to evaluate the effect of anesthetic and procedural modifiers.

Results: The combined incidence of OCR in ophthalmic environments was 34.6% (95% CI: 29.140.2), with a large variance between studies. More OCR episodes, as well as their severity, were linked to lighter planes of anesthesia, administration of fast, acting opioids, use of dexmedetomidine, extraocular muscle traction, and re, operative strabismus surgery. On the other hand, ketamine, based anesthesia and topical ocular anesthetics were linked with decreased OCR incidence. Mild bradycardia was the predominant symptom, whereas severe OCR was observed in less than 5% of cases. Retinal examinations on neonates caused a significant heart rate drop that was clinically relevant despite the fact that the stimulus was non, surgical. OCR has also been linked to an increased risk of postoperative nausea and vomiting in pediatric strabismus surgery.

Conclusion:  The oculocardiac reflex (OCR) is still a common and significant clinical event in eye care practice. OCR is very much determined by the type of anesthesia used, the presence of opioids and sedatives, and the nature of the surgery. The implementation of specific measures to prevent OCR, such as well, planned anesthetic methods, minimal opioid use, use of topical ocular anesthesia, and delicate surgical maneuvers, may contribute to lowering the OCR rate and the resulting complications. There is a necessity for agreed, upon OCR criteria and prospective research to advance the OCR management protocols in light of the latest evidence