Alternative mydriasis techniques for retinopathy of prematurity screening

Mydriasis for retinopathy of prematurity screening in Europe: A cross-sectional online survey

PURPOSE

To compile real-time data on the preferred mydriasis practice patterns for retinopathy of prematurity (ROP) screening in Europe.

METHODS

A cross-sectional online survey was conducted from December 2022 to January 2023, using a self-report online questionnaire which was distributed via email to the members of the European Pediatric Ophthalmological Society and the Greek National ROP Task Force. A six-week period of recruitment was determined, and a reminder email was sent after two weeks. Descriptive statistics were used to explore the data, which was summarized with frequencies and percentages.

RESULTS

Sixty-six responses were recorded (response rate: 29.5%), representing practices in 55 Neonatal Intensive Care Units from 21 European countries. In 94.5%, the applied mydriatic regimen consists of phenylephrine with at least one muscarinic antagonist, either tropicamide or cyclopentolate. The concentration of phenylephrine ranges from 0.5% to 5%, of tropicamide from 0.25% to 1%, and of cyclopentolate from 0.2% to 1%. The most commonly used regimen (43.6%) contains phenylephrine 2.5% and tropicamide 0.5%, administered either combined or separately. About 54.5% of the reported mydriatic solutions are non-commercial, in-house preparations. Systemic adverse events, including oxygen desaturation, bradycardia and cardiopulmonary arrest were reported in 14.5%.

CONCLUSION

There is considerable heterogeneity in the applied mydriatic regimens for ROP screening in Europe, reflecting the absence of universal guidelines. The wide use of in-house preparations underlines the gap in the pharmaceutical industry. Concern should be raised against the wide use of undiluted commercial drugs, that reach adult dose, in the fragile population of preterm infants.

Pathogenesis and prevention of intraventricular hemorrhage

Despite improvements in the mortality rates of preterm infants, rates of germinal matrix intraventricular hemorrhage (IVH) have remained static with an overall incidence of 25% in infants less than 32 weeks. The importance of the lesion relates primarily to the underlying injury to the developing brain and the associated long-term neurodevelopmental consequences. This clinical-orientated review focuses on the pathogenesis of IVH and discusses the evidence behind proposed prevention strategies.

Efficacy and safety of Mydriatic Microdrops for Retinopathy Of Prematurity Screening (MyMiROPS): study protocol for a non-inferiority crossover randomized controlled trial

BACKGROUND

Retinopathy of prematurity (ROP) eye examination screening presupposes adequate mydriasis for an informative fundoscopy of preterm infants at risk, on a weekly basis. Systemic absorption of the instilled mydriatic regimens has been associated with various adverse events in this fragile population. This report aims to present the fully developed protocol of a full-scale trial for testing the hypothesis that the reduced mydriatic drop volume achieves adequate mydriasis while minimizing systemic adverse events.

METHODS

A non-inferiority crossover randomized controlled trial will be performed to study the efficacy and safety of combined phenylephrine 1.67% and tropicamide 0.33% microdrops compared with standard drops in a total of 93 preterm infants requiring ROP screening. Primary outcome will be the pupil diameter at 45 (T45) min after instillation. Pupil diameter at T90 and T120 will constitute secondary efficacy endpoints. Mixed-effects linear regression models will be developed, and the 95% confidence interval approach will be used for assessing non-inferiority. Whole blood samples will be analyzed using hydrophilic liquid chromatography-tandem mass spectrometry method (HILIC-MS/MS), for gathering pharmacokinetic (PK) data on the instilled phenylephrine, at nine specific time points within 3 h from mydriasis. Pooled PK data will be used due to ethical restrictions on having a full PK profile per infant. Heart rate, oxygen saturation, blood pressure measurements, and 48-h adverse events will also be recorded.

DISCUSSION

This protocol is designed for a study powered to assess non-inferiority of microdrops compared with standard dilating drops. If our hypothesis is confirmed, microdrops may become a useful tool in ROP screening.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05043077 . Registered on 2 September 2021.

Efficacy and safety of mydriatic microdrops for retinopathy of prematurity screening: an external pilot crossover randomized controlled trial

OBJECTIVE

To study the efficacy and safety of mydriatic microdrops compared with standard drops for retinopathy of prematurity (ROP) screening.

STUDY DESIGN

Preterm infants undergoing ROP screening received microdrops and standard drops of phenylephrine 1.67% and tropicamide 0.33% in a random allocation sequence at two consecutive weekly examinations. Primary outcome was pupil diameter measured by two masked observers at 45 (T45) and 90 (T90) minutes after instillation.

RESULTS

Twenty-five infants were randomized. No differences observed in mean pupil diameter after either administration technique at all time points (T45 Mean Difference: -0.14; 95% Confidence Interval: -0.38, 0.09; p = 0.23). Heart rate values at T120 were lower after microdrop instillation (p = 0.046). Otherwise, adverse events did not differ after either administration technique.

CONCLUSION

This pilot study provides evidence of microdrops mydriasis efficacy, while justifying a full-scale trial to confirm their non-inferiority compared with standard drops and provide more data about safety.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04623684.