The Pain Relief Effect of Cold Normal Saline Eye Irrigation before Intravitreal Injections: A Double-Blind Randomised Controlled Trial
Nattapon Wongcumchang*, Pulthip Charoenphol
Department of Ophthalmology, Faculty of Medicine, Thammasat University, Thailand; E-mail:
Purpose: This study evaluated the effect of cold normal saline eye irrigation on pain sensation during intravitreal injections. We compared the adjunctive method with the standard intravitreal injection procedure.
Methods: We conducted a randomized, single-centre controlled trial. In this study, 64 patients were scheduled for intravitreal anti-vascular endothelial growth factors (Anti-VEGF) injection. Randomized patient ratio was 1:1 Topical anesthesia of 0.5% tetracaine was obtained in all patients. After a standard aseptic procedure, Cold NSS Eye Irrigation was performed. The pain evaluation was tested immediately and 30 minutes after the injection with the Visual Analogue Scale (VAS) and Short-form McGill Pain Questionnaire. 30 minutes after injection, The area of subconjunctival haemorrhage (SCH) has been recorded.
Result : Sixty-four patients were analysed. Baseline patient characteristics were similar except for previous cataract surgery history. Pain score was analysed during immediate injection by VAS. Mean pain score was 0.97 + 1.06 in the cold NSS Eye Irrigation and 4.53 + 1.50 in the control group (p < 0.001). After 30-minute post- intravitreal injection, the mean pain score in the cold NSS Eye Irrigation was 0.22 + 0.75 and 3.16 + 0.99 in the control group. SCH incidence was 40.6% in the Clod NSS Eye Irrigation group and 90.6% in the control group. Mean area of SCH in the Cold NSS Eye Irrigation group was 0.44 + 0.56 clock-hour and 1.45 + 0.65 clock-hour in the control group (p < 0.001). The differences in pulse rate and oxygen saturation which recorded using pulse oximetry were not statistically significant between both groups.
Conclusion : Cold Normal Saline eye Irrigation could be an effective pain-relief method during intravitreal injections. This adjunctive method can decrease pain intensity and area of subconjunctival haemorrhage after intravitreal injections.
Eye South East Asia ปี 2564, January-June ปีที่: 16 ฉบับที่ 1 หน้า 23-32
pain, pain score, Topical anesthesia, intravitreal injections, cold effect