Impact of Periocular Vibration on Pain Perceived during Intravitreal Injections
January 2020
Adam MK, Zheng CX, Fineman MS. Impact of Periocular Vibration on Pain Perceived during Intravitreal Injections. Ophthalmol Retina. 2020; 4(1): 113-115.
“Cross my heart and hope to die, stick a needle in my eye…”
While it is unclear if the phrase above originated as a children’s poem from southern England or a pre-reformation oath from the book of Matthew, we can all agree: people don’t like needles in their eyeballs. As intravitreal injections have become increasingly common, sometimes we forget this.
Anti-VEGF agents are the gold standard for treating a number of retinal pathologies, but the pain caused by the injection process causes significant patient anxiety and decreased treatment adherence. We’ve all had patients who either refuse injections altogether or just don’t show up for follow-up visits, leading to vision loss or even blindness. Current methods for local anesthetic include topical drops, gels, pledgets, subconjunctival injections, and even peribulbar injection—but some patients still experience discomfort.
Vibration anesthesia is a well-established method to reduce pain associated with gingival and dermal anesthesia administration and achieves antinociception via inhibition of afferent pain receptors. In a prospective, randomized clinic trial of 80 patients with neovascular age-related macular degeneration, Adam et al. investigated whether a fingertip vibrator (Hello Touch Wearable Vibrator, Jimmyjane) applied to the infraorbital foramen and nerve during intravitreal injection could improve patient comfort. Outcome measurements were perceived patient pain using a standardized 10-point Wong-Baker faces pain scale and the proportion of patients reporting a pain score of 0 at the time of treatment. Both treatment groups received topical anesthetic drops and all patients had previously received intravitreal injections.
Treatment with periocular vibration anesthesia was associated with approximately 40% less pain than standard intravitreal injections (Pain Scale: 1.54 vs 2.49; p=0.01). Impressively, nearly twice as many patients reported a pain score of 0 in the vibration anesthesia group (34.1% vs. 17.9%; p=0.08). No significant adverse events were observed in either treatment group.
The effect of vibration on pain mediation is thought to be related to gate control theory, which hypothesizes that vibratory sensory A-β nerve fibers stimulate inhibitory spinal cord interneurons and reduce pain transmission. The reported 40% pain reduction in this study is similar to prior reports using vibration anesthesia for dermatologic applications (44% reduction) and more effective than other ophthalmic interventions including smaller gauge needles (no significant pain decrease) and manual lid retraction (33% decreased discomfort).
The Hello Touch Wearable Vibrator was not intended for use as a medical device; the authors should be applauded for their creativity as they have found a unique, effective, and low-cost method for improving patient comfort. Far too often, we forget the pain, anxiety, and burden caused by our treatments. While anti-VEGF injections have revolutionized our care and preserved vision in countless individuals with retinal pathology, we must remember the importance of the patient experience as we strive to fight blindness.
