Effect of Benoxinate Hydrochloride Eye Drops on the Premature Infant Pain Profile Score during Retinopathy of Prematurity Screening

Abstract

Aims: The aim of the study was to evaluate the effects of benoxinate hydrochloride (HCL) eye drops on premature infant pain profile (PIPP) scores in infants undergoing retinopathy of prematurity (ROP) screening. Methods: A randomized prospective double-masked cross-over trial was conducted on infants screened for ROP at least twice. The first fundus examination was done in Group A using the tear substitute eye drops and the second using the benoxinate HCL drops. A reversed order of drops was used for Group B. Video recording of the pulse oximeter monitor, the face and the body of the infant were analyzed by a single neonatology consultant for PIPP scoring 1 min before, during each stage of the first eye examination, i.e., lid speculum insertion, shining of the indirect ophthalmoscope light and the scleral indentation (indicated by the sound of the ophthalmologist on the video), 1 and 5 min after the examination of the second eye. Results: The study included 88 infants. The PIPP scores were similar in both groups during the first and the second examinations. The average PIPP score was higher when using the tear substitute drops than with the benoxinate HCL drops. A higher percentage of infants examined with the tear substitute drops than those examined with the benoxinate HCL drops had a difference ≥4 from baseline PIPP scores (indicating infant stress) or PIPP 7–12 (indicating intermediate pain) but the differences were not statistically significant. Conclusion: Benoxinate HCL drops did not provide a significant reduction of the infant stress during the ROP screening.