Lack of evidence and consequential harm caused by mydriatic regimens used in retinopathy of prematurity screening.

Abstract

Approximately 3,500 infants in New Zealand and Australia are screened annually for retinopathy of prematurity (ROP). To view the retina and diagnose ROP, adequate pupil dilation with mydriatic medicines is required.

Although mydriatic drops are in common use in NICUs, there is no established or preferred mydriatic regimen in New Zealand and Australia. A literature review revealed that there is very limited literature involving only pilot studies on which international mydriatic guidelines are based. Results from these pilot studies suggest that there is very little benefit in administering larger doses when smaller doses are effective.

A survey of New Zealand and Australian neonatal nursing staff identified 11 different mydriatic regimens, highlighting the need for robust evidence to guide clinical practice. Within these 11 mydriatic regimens, there was up to a 27-fold difference in total dose. Only 22% of the respondents indicated using a microdrop to reduce the total dose. The larger the total dose of mydriatic medicines, the higher the risk for adverse events. Adverse events that neonatal nurses reported after mydriatic administration were; hypertension, tachycardia, apnoea, feed intolerance, abdominal distension, necrotising enterocolitis, death and periorbital pallor.

The findings indicate the need for further evidence to support the dosing of mydriatics in neonates. There is a need for a RCT to investigate the use of low dose cyclopentolate and phenylephrine by comparing a standard drop to a microdrop. Results from the RCT will provide evidence for international guidelines, and therefore guide clinical practice.