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Randomised controlled pilot trial comparing low dose and very low- dose microdrop administration of phenylephrine and cyclopentolate for retinopathy of prematurity eye examinations in neonates
  1. Lisa Jean Kremer1,2,
  2. Roland Broadbent3,
  3. Natalie Medlicott1,
  4. Mary Jane Sime4,
  5. Frances McCaffrey5,
  6. David M Reith2
  1. 1School of Pharmacy, University of Otago, Dunedin, New Zealand
  2. 2Department of Women’s and Children’s Health, University of Otago, Dunedin, New Zealand
  3. 3Department of Women’s and Children’s Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
  4. 4Ophthalmology, Southern District Health Board, Dunedin, New Zealand
  5. 5Neonatal Intensive Care Unit, Dunedin Hospital, Dunedin, New Zealand
  1. Correspondence to Lisa Jean Kremer, School of Pharmacy, University of Otago, Dunedin 9054, New Zealand; lisa.kremer{at}


Aims To determine if

  • Very low dose mydriatic eye microdrop regimen sufficiently dilates the pupil (above 4.1 mm) compared with the currently used low dose mydriatic eye microdrop regimen.

  • Cardiovascular, gastrointestinal and respiratory adverse effects occur following eye drop instillation.

Methods Seventeen premature infants were recruited into this prospective, randomised controlled pilot trial in January 2017 to November 2018. Data were collected from the single-centre Neonatal Intensive Care Unit, Dunedin Hospital, New Zealand. The inclusion criteria were birth weight less than 1500 g or gestational age less than 31 weeks, or any premature infant requiring red reflex testing. Infants were randomised to receive either phenylephrine 1% or 0.5% and cyclopentolate 0.2% or 0.1%, 1 microdrop in both eyes. Efficacy outcome measures were pupil size at retinopathy of prematurity eye examination (ROPEE) and ophthalmologist rating of ease of screen.

Results All participants had sufficient pupillary dilation for a successful ROPEE. Ophthalmologists rated the ROPEE as easy for 90% of all examinations. Pupil dilation measurements at the time of examination, mean±SD, 4.8±0.2 (95% CI 4.5 to 5.2) mm for treatment A and 5±0.2 (95%CI 4.6 to 5.4) mm for treatment B (p=0.61). There were no statistically significant differences between the groups for safety data.

Conclusions Very low dose microdrop administration of phenylephrine and cyclopentolate appears to be effective at sufficiently dilating the neonatal pupil for ROPEEs. Low dose and very low dose microdrop mydriatic regimens may also reduce the risk of unwanted adverse effects associated with these medicines.

Trial registration number Australian New Zealand Clinical Trials Registry (reference ACTRN12616001266459p).

  • neonatology
  • ophthalmology
  • phenylephrine
  • cyclopentolate
  • retinopathy of prematurity

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  • Contributors RB suggested the topic for the study. DMR, LJK, RB and NM designed the study, wrote the study protocol and obtained ethics. FM facilitated recruitment and provided comments on the publication. LJK collected and analysed the data, and wrote the publication. RB, DMR, MJS and NM provided comments, supervision and support throughout.

  • Funding New Zealand Pharmacy Education Fund for funding the Colvard Pupilometer, and the University of Otago PhD stipend for LJK.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval This study received ethical approval by the Central Health and Disability Ethics Committee, Wellington, New Zealand (reference 16/CEN/135/AM01), and locality approval by Health Research South, Dunedin, New Zealand. Māori consultation occurred with both the Ngāi Tahu Research Committee, University of Otago, and with an Ōtakou Rūnaka representative.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available on reasonable request. IPD and related data dictionaries are available. All non-­identifiable data; individual participant data underlying published results only. Data will be available immediately following publication and until 31 December 2021. Data are available only to researchers who provide a methodologically sound proposal, on a case­-by-case basis, at the discretion of this study's PI. Data will be provided for any type of analyses, only to achieve the aims in the approved proposal, for IPD meta-analyses, as deemed fit by this study's PI. Data can be obtained by access subject to approvals by this study's Principal Investigator, with a requirement to sign a data access agreement. The study protocol, informed consent form and ethical approval are also available if needed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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