During manipulation of ocular structures, especially traction on the extraocular muscles during ophthalmic surgery, the well-known trigeminovagal reflex known as the oculocardiac reflex (OCR) takes place. The trigeminal nerve's ophthalmic division serves as the reflex's afferent pathway, and the vagus nerve serves as its efferent pathway [1, 2]. This causes the heart to be parasympathetically stimulated. Clinically, OCR is characterised by an abrupt drop in heart rate, usually defined as a drop of 20% or more from baseline, however it can also manifest as atrioventricular block, arrhythmias, hypotension, or, in rare instances, cardiac arrest [3, 4]. One of the most frequent ocular treatments related to OCR is strabismus surgery. Due to elevated autonomic reactivity and vagal tone, the reflex is especially common in paediatric patients. OCR during surgery is known to be significantly triggered by manipulation of the extraocular muscles, particularly the medial rectus muscle. Severe cases may cause significant haemodynamic instability and necessitate prompt care, even though the majority of episodes are temporary and end as muscle traction is stopped [5, 6]. The incidence and severity of OCR are influenced by various circumstances. Contributing factors include younger age, insufficient depth of anaesthesia, hypoxaemia, hypercapnia, administration of specific anaesthetic drugs, and prolonged or strong extraocular muscle tension. The possibility of developing OCR may also depend on the kind and quantity of extraocular muscles that are operated upon. To anticipate and avoid potentially dangerous cardiovascular problems after surgery, it is crucial to comprehend these risk factors [7]. For strabismus surgery, especially in youngsters, general anaesthesia is frequently used to guarantee immobility, patient comfort, and ideal operative conditions. OCR is still a common occurrence during these surgeries, despite with improvements in anaesthetic methods and intraoperative monitoring. For the early diagnosis and treatment of OCR, continuous contact between the surgeon and anaesthesiologist as well as ongoing electrocardiographic monitoring are consequently essential [8]. Despite the fact that OCR during ophthalmic surgeries has been the subject of several research, reported incidence rates and risk factors vary depending on patient characteristics, surgical techniques, and anaesthetic protocols. Therefore, it is still crucial to keep evaluating OCR in certain clinical contexts in order to improve perioperative care and patient safety [9, 10]. The goal of the current study was to ascertain the prevalence of oculocardiac reflex and pinpoint risk factors in patients having general anaesthesia for strabismus surgery. In order to promote early detection, prevention, and efficient management of this significant intraoperative complication, the study sought to assess the link between patient demographics, surgical factors, and the incidence of OCR.

This prospective observational study was conducted in the Department of Ophthalmology, Kanya Kumari Medical Missions Medical College, Kanyakumari, Tamil Nadu, between July 2024 and June 2025. A total of 30 patients undergoing elective strabismus surgery under general anesthesia were included in the study after obtaining written informed consent from the patients or their guardians. Ethical approval for the study was obtained from the Institutional Ethics Committee prior to commencement. All patients underwent detailed preoperative ophthalmological examination, anesthetic assessment, and routine laboratory investigations before surgery. Methods: Patients' age, gender, weight, strabismus type, number and kind of extraocular muscles operated on, surgery length, and anaesthetic data were meticulously documented. Electrocardiography, heart rate, blood pressure, oxygen saturation, and end-tidal carbon dioxide were monitored during general anaesthesia per institutional recommendations. The patient's baseline heart rate was checked before surgery. The oculocardiac reflex occurs when pressure on an extraocular muscle lowers heart rate by 20%. When, severity, and management of OCR occurrences were recorded during operation. It was recorded which muscles were utilised for OCR, when traction was ceased, when atropine was given, and any haemodynamic alterations. Cardiovascular issues like arrhythmias and hypotension were monitored throughout surgery. Inclusion Criteria: • Patients undergoing elective strabismus surgery under general anesthesia. • Patients aged 5 years and above. • Patients with unilateral or bilateral strabismus requiring surgical correction. • Patients classified as American Society of Anesthesiologists (ASA) Grade I or II. • Patients or guardians willing to provide written informed consent. Exclusion Criteria: • Patients with known cardiac arrhythmias or significant cardiovascular disease. • Patients receiving medications affecting heart rate such as beta-blockers or antiarrhythmic drugs. • Patients with previous strabismus surgery. • Patients with neurological disorders affecting autonomic function. • Patients with uncontrolled systemic illnesses. • Patients requiring emergency ophthalmic surgery. • Patients or guardians unwilling to participate in the study. Statistical Analysis: After entering the data into Excel, we ran the numbers via SPSS version 26.0. Categorical data were represented using frequencies and percentages, whereas continuous variables were shown as mean ± standard deviation (SD). When looking for a correlation between OCR and categorical variables including age, gender, operated muscle type, and total number of muscles, researchers utilised either Fisher's exact test or a Chi-square test. The Student's t-test was used to compare continuous variables. The occurrence of OCR was investigated using multivariate analysis in order to find independent risk factors. A p-value lower than 0.05 was considered statistically significant.

A total of 30 patients undergoing strabismus surgery under general anesthesia were included in the study. The incidence of oculocardiac reflex (OCR), associated risk factors, intraoperative characteristics, and management outcomes were analyzed. Table 1: Demographic Characteristics of Study Participants Variable Number (%) Total Patients 30 Male 18 (60.0%) Female 12 (40.0%) Mean Age (Years) 11.8 ± 5.6 Age <15 Years 20 (66.7%) Age ≥15 Years 10 (33.3%) Table 1 shows that the majority of patients were male and below 15 years of age. Table 2: Incidence of Oculocardiac Reflex Parameter Number (%) OCR Present 11 (36.7%) OCR Absent 19 (63.3%) Table 2 demonstrates that OCR occurred in 11 patients (36.7%), while 19 patients (63.3%) did not develop the reflex during surgery. Table 3: Association of OCR with Age Age Group OCR Present OCR Absent Total p-value <15 Years 10 (50.0%) 10 (50.0%) 20 0.03 ≥15 Years 1 (10.0%) 9 (90.0%) 10 Table 3 shows that OCR was significantly more common among patients younger than 15 years compared to older patients. Table 4: Extraocular Muscle Involved During OCR Episodes Muscle Operated OCR Cases (n=11) Percentage Medial Rectus 6 54.5% Inferior Rectus 2 18.2% Lateral Rectus 2 18.2% Superior Rectus 1 9.1% Table 4 demonstrates that traction on the medial rectus muscle was associated with the highest incidence of OCR. Table 5: Association of OCR with Number of Muscles Operated Surgical Procedure OCR Present OCR Absent p-value Single Muscle Surgery (n=18) 4 (22.2%) 14 (77.8%) 0.04 Multiple Muscle Surgery (n=12) 7 (58.3%) 5 (41.7%) Table 5 shows that OCR occurred significantly more frequently in patients undergoing surgery involving multiple extraocular muscles. Table 6: Management and Outcome of OCR Episodes Management Parameter Number (%) Resolved with Release of Muscle Traction Alone 7 (63.6%) Required Intravenous Atropine 4 (36.4%) Persistent Arrhythmia 0 (0.0%) Severe Hemodynamic Instability 0 (0.0%) Surgery Terminated Due to OCR 0 (0.0%) Table 6 shows that most OCR episodes resolved after temporary cessation of extraocular muscle traction. Four patients required atropine administration for persistent bradycardia. No serious cardiovascular complications were observed.

One of the most common cardiovascular reflexes during ophthalmic surgery is the oculocardiac reflex (OCR), which continues to be a major problem during general anesthesia-assisted strabismus treatments. Bradycardia and other heart rhythm abnormalities are caused by the reflex, which is mediated by the trigeminal-vagal pathway and is usually initiated by traction on extraocular muscles. Severe symptoms can cause haemodynamic instability if they are not identified and treated quickly, even though the majority of episodes are brief and reversible. The current study assessed the prevalence of OCR during strabismus surgery and determined risk factors [11-13]. In the current study, 36.7% of individuals having strabismus surgery experienced OCR. This prevalence is similar to that seen in earlier research, where the incidence of OCR has varied from 20% to 70%, contingent on surgical variables, anaesthetic method, and patient age. Variations in patient groups, perioperative care practices, and the definition of OCR could all contribute to the reported incidence's fluctuation [14, 15]. The prevalence of OCR was found to be significantly influenced by age. Compared to older people, patients under the age of fifteen showed a noticeably higher incidence of the reaction. This result is in line with earlier research showing that children are more vulnerable to OCR during ocular manipulation due to higher vagal tone and autonomic responsiveness. The need for careful cardiovascular monitoring after paediatric strabismus surgery is highlighted by the higher frequency among younger patients [16, 17]. The current investigation showed that the greatest frequency of OCR events was linked to traction on the medial rectus muscle. When this muscle was manipulated, more than half of all reflex events were noted. Due to its tight physical association with the trigeminal nerve pathways and high sensory innervation, the medial rectus has been found in previous studies to be the most powerful activator of OCR. Therefore, especially in high-risk patients, surgeons should be cautious while dissecting and tractioning the medial rectus [18, 19]. The incidence of OCR is significantly influenced by general anaesthesia. While mild anaesthesia may enhance vulnerability, adequate anaesthetic depth has been demonstrated to decrease reflex activity. OCR nevertheless happened in a sizable percentage of patients even if anaesthetic depth was maintained in accordance with institutional norms in the current investigation, suggesting that surgical stimulation is still a significant contributing factor. Thus, early detection and treatment of reflex episodes depend on constant contact between the anaesthesiologist and the surgeon [20, 21]. There are some limitations to the current investigation. The study was carried out at a single tertiary care facility and had a rather small sample size, which may have limited how broadly the results may be applied. Furthermore, individual autonomic responses and differences in anaesthetic drugs were not thoroughly examined. A more thorough understanding of OCR and its determinants might be possible with larger multicenter investigations [22, 23].

With an incidence of 36.7%, the current study showed that the oculocardiac reflex is a frequent intraoperative occurrence during strabismus surgery under general anaesthesia. Medial rectus muscle traction, multiple-muscle surgery, and younger age were found to be important risk factors for its occurrence. A few OCR incidents needed to be treated with atropine, but the most were brief and ended with a brief stop to muscle traction. There were no significant cardiovascular issues found. During strabismus surgery, patient safety and good surgical results depend on careful intraoperative monitoring, sufficient anaesthetic depth, and timely control of OCR.

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