Anxiety levels and perceived pain intensity during intravitreal injections.

Abstract

The number of intravitreal anti-vascular endothelial growth factor (VEGF) injections has increased to a point that they are now second only to cataract surgery as the most common treatment in most tertiary ophthalmic centres across Europe and the United States (Holz et al. 2005). The pain endured during the procedure may affect their overall comfort and reduce compliance (Cintra et al. 2009) which may prove critical in diseases require recurring injections. Therefore, the purpose of this study was to evaluate the correlation between pain associated with intravitreal bevacizumab injections and the patient's perceived anxiety level before the injection. The study and data accumulation were carried out with approval from the Meir Medical Center Institutional Review Board and adhered to the tenets of the Declaration of Helsinki. All the patients included in this prospective, consecutive, observational, non-interventional study received intravitreal bevacizumab injections at our Retina Clinic between September 2011 and March 2013. Exclusion criteria were age below 18 years and anterior segment conditions that could affect pain sensation. Patients were asked during the routine preprocedural intake to plot their anxiety level using the visual analogue scale for anxiety (VASA) on a scale from 0 to 10 with ‘no anxiety or fear’ scored as 0 and ‘unbearable anxiety or fear’ scored as 10. Immediately after receiving the injection, the subject was asked to plot their experienced level of pain during the injection using a visual analogue scale (VAS) for pain also on a scale from 0 to 10. Anaesthetic technique was uniform for all participants and included 1 ml of 2% lignocaine gel 5 min prior to injection. All injections were performed using straight injection technique with a 30-gauge needle (Knecht et al. 2009). Overall, 225 eyes of 225 patients were included in the final analysis of this study. The age of the participants was 74.26 ± 12.72 years and 44.4% were male. In 25% (n = 56) of the participants, VASA levels were greater or equal to 6 and in 8.4% (n = 19) VAS levels greater or equal to 6. The results of the univariate correlational analyses between VAS and preprocedural parameters are depicted in Table 1. Only VASA demonstrated a significant positive correlation with VAS (R2 = 0.27, p = 0.005). Tables 2-4 detail the analyses of categorical preprocedural parameters and respective VAS scores. Retired patients had higher VAS scores than those still employed (p = 0.01), and patients who had undergone a previous ocular operation demonstrated significantly lower VAS scores than those who had not (p = 0.03). Significant differences in the VAS scores of the different surgeons (p < 0.001) (Table 3) and of the different diagnoses leading to injections (p = 0.004) (Table 4) were found. Preprocedural VASA score and the surgeon remained significant in stepwise backwards multiple regression analysis, explaining 20.92% of variation in VAS scores (p < 0.001). Women were more anxious than men (p = 0.04), a finding that remained significant in stepwise backwards regression, explaining 1.82% of the VASA score variation (p = 0.04). To the best of our knowledge, this is the first study to report a relationship between preprocedural anxiety and pain in intravitreal injections. The surgeon performing the injection and VASA scores were the only parameters that remained significant in stepwise multiple regression analysis (p < 0.001) demonstrating a correlation between increased preprocedural anxiety and perceived pain in intravitreal injection. As decreased anxiety may perhaps lead to reduced pain, it may be beneficial to explore ways to reduce anxiety in outpatient intravitreal injections. Chen et al. (2012) reported that diversion methods such as listening to classical music before and during intravitreal injections significantly decreased anxiety in patients. The large number of patients worldwide receiving monthly injections for long periods of time, and the fact that one quarter of the patients in this study demonstrated high levels of VASA (>=6) and nearly 10% high levels of VAS (>=6), emphasizes that surgeons should continue to pursue methods of reducing anxiety and pain for intravitreal injections.