Effect of topical anesthesia and age on pain scores during retinopathy of prematurity screening

Abstract

Objective: The efficacy of topical anesthesia during retinopathy of prematurity (ROP) screening has been a controversial issue. To determine the efficacy of proparacaine eye drops (0.5%), we compared the Premature Infant Pain Profile (PIPP) scores in 40 preterm infants undergoing ROP screening.

Study design: Prospective randomized double masked cross-over clinical trial. The study was conducted in the neonatal intensive units for infants undergoing routine ROP screening exams. Baseline PIPP scores and post-examination PIPP scores at 1 and 5 min were compared for: (1) those receiving saline vs proparacaine eye drops (2) first ROP screening vs second ROP screening, regardless of the type of eye drops used. Wilcoxon signed-ranks test was used to pair pain scores.

Result: Forty preterm infants were included in the study. Mean gestational age (GA) at first and second examinations was 33.3 and 35.3 weeks, respectively. Proparacaine use significantly lowered mean PIPP scores (P=0.027) and delta scores (P=0.013) at 1 min after examination, but there was no difference at 5 min after examination. Second examinations showed significantly lower mean PIPP scores after examination (1 min (P=0.003) and 5 min (P=0.025)), regardless of the type of drop used.

Conclusion: Proparacaine eye drops offer significant relief of pain that is apparently short lived. Significantly lower PIPP scores at second ROP examinations suggested that infants of older GA may have a greater ability to tolerate ROP screening. We recommend the use of proparacaine eye drops for the short term, immediate relief of pain during ROP screening in preterm infants of lesser GA.