Editor, The oculocardiac reflex (OCR) is defined by the appearance of bradycardic arrhythmia and reduced arterial pressure and may be associated with a symptomatic vagal response consisting of nausea and vomiting. The OCR may be elicited by pressure on the globe – as occurs in acute glaucoma (Faupel & Niedermeier 1970) and extracapsular cataract surgery (Gao et al. 1997) – among other causes. The purpose of this study is to assess the appearance of OCR during phacoemulsification. A prospective, interventional study was performed on 122 consecutive patients who were operated on by uneventful phacoemulsification. Written informed consent was obtained from the patients prior to the procedure and data gathering. The procedures were performed in accordance with the ethical standards of the 1964 Declaration of Helsinki. Three different modalities of anaesthesia [peribulbar blockade (PB), topical anaesthesia (TA) and topical + anterior chamber anaesthesia (TACA)] were used depending on the preferred clinical practice of each of the surgeons. PB was performed by injection of 3 ml 2% lidocaine and 3 ml 0.5% bupivacaine; TA was performed by the instillation of tetracaine 0.5% in the conjunctival cul de sacs. TACA was performed as TA plus 0.1 ml 2% lidocaine in the anterior chamber. The patients were operated on by ‘divide and conquer’ phacoemulsification and were monitored during surgery by chest electrodes. The heart rate (HR) was determined immediately before surgery (basal) and 10 seconds after starting continuous anterior chamber infusion at 95 cm H2O (≈ 70 mmHg). OCR was defined by a decrease in HR greater than 15% from baseline (Karanovic et al. 2006). The concomitant medical treatment given prior to surgery and during surgery was registered. Sixteen patients were operated on under PBA, 39 patients under TACA and 67 patients under TA. The results are shown in Table 1. The HR in the whole group decreased from an average 71.3 ± 11.3 beats per minute (bpm) to 68.9 ± 12.3 bpm (p= 0.0006); a reduction ≥ 15% was observed in 19 patients from an average 71.4 ± 9.4 to 58.4 ± 7.5 bpm (p< 0.001; Student’s t-test for paired data). Considering the different modalities of anaesthesia, OCR appeared in 1/15 patients under PB and in 3/40 patients under TACA, compared with 15/67 patients under TA (t = 2.26, p= 0.03, simple linear regression). OCR appeared more frequently among patients older than 75 years (t = 2.65, p= 0.01, simple linear regression). A symptomatic vagal response in the form of nausea and vomiting did not appear in any case. None of the patients required pharmacological treatment or change in the surgical schedule. Since the first reports on the use of topical anaesthesia for cataract surgery were published (Kershner 1993), a trend towards a widespread indication of topical anaesthesia exists. However, we should be aware that phacoemulsification with TA is more painful than with PBA and that the effect of pain may induce changes in systemic objective parameters such as white blood cell count, cortisol levels and systemic arterial pressure (Gombos et al. 2007). Different combinations of anaesthetic drugs have reported either for PB blockade (Borazan et al. 2008) or as a combination of topical plus peribulbar anaesthesia (Monteiro et al. 2007). Modern cataract surgery involves sudden rises and drops in intraocular pressure (IOP) (95 cm H2O ≈ 70 mmHg), which might be associated with a decreased HR or other vagal signs. Pain may also play a role in the appearance of OCR, and increased analgesia may reduce the frequency of OCR in patients undergoing retinal surgery (Vlajkovic et al. 2007) – although opioids may induce OCR (Snellen et al. 1993). In our study, fentanyl did not seem to influence the changes in HR. Symptomatic OCR was not detected in any patient in our series, which may explain why the appearance of OCR has not been reported during phacoemulsification previously. We would like to alert cataract surgeons of a potential risk of bradycardia in older patients (especially when performing topical anaesthesia in outpatient non-hospital settings). Further studies assessing changes in HR are required in order to determine the effect of IOP rises during phacoemulsification.