A Phase 4 interventional study of Microdrop administration of phenylephrine 1.67% and tropicamide 0.33% and Standard drop administration of phenylephrine 1.67% and tropicamide 0.33% in Retinopathy of Prematurity, sponsored by Aristotle University Of Thessaloniki. Completed at 1 site in Greece. Open to participants aged 30 Weeks to 36 Weeks. Per ClinicalTrials.gov, last updated 2025-03-18.
Sponsored by Aristotle University Of Thessaloniki · Phase 4, Interventional, and Screening
The purpose is to test the hypothesis that microdrop instillation of combined phenylephrine 1.67% and tropicamide 0.33% eyedrops causes at least equal mydriasis compared with standard drop instillation of the same mydriatic regimen, which constitutes routine care for pupil dilation during retinopathy of prematurity (ROP) screening in our neonatal intensive care unit. Comparison, also, will be made to the subsequent adverse events and the drug concentration in peripheral blood samples.
A non-inferiority, crossover, randomized controlled trial will be conducted for this purpose. Participants will be randomly assigned to receive either a) microdrops on their first and standard drops on their second screening examination a week later (M/S group), or b) standard drops first and microdrops a week later (S/M group). Microdrops (6.5 μL) will be instilled using a calibrated micropipette, while standard drops (28-34 μL) will be instilled directly through the commercially available plastic multi-dose mydriatic dropper bottle.
815 studies on the registry are indexed under Retinal Diseases; 105 are open to participants now.
This study's enrollment of 83 is above the median of 60 across 500 interventional studies indexed under Retinal Diseases.
Browse Retinal Diseases studies →Aristotle University Of Thessaloniki is the lead sponsor of 274 studies on the registry; 56 are open to participants now.
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Preterm infants undergoing screening for ROP, i.e.
Exclusion Criteria:
Mydriasis with microdrops
Drug: Microdrop administration of phenylephrine 1.67% and tropicamide 0.33%
Mydriasis with standard drops
Drug: Standard drop administration of phenylephrine 1.67% and tropicamide 0.33%
1 drop (6.5 μL) for 3 doses with 5-minute intervals
1 drop (28-34 μL) for 3 doses with 5-minute intervals
Mydriatic efficacy: millimeters of horizontal pupil diameter.
Time frame: 45 minutes after the first drop instillation.
Mydriasis sustainability: millimeters of horizontal pupil diameter.
Time frame: 90 minutes after the first drop instillation.
Mydriasis sustainability: millimeters of horizontal pupil diameter.
Time frame: 120 minutes after the first drop instillation.
Pharmacokinetic profile of phenylephrine: area under the whole blood concentration versus time curve (AUC).
Each participant will be sampled once (random allocation to one time-point). Blood sampling will be combined with peripheral blood collection for routine examinations.
Time frame: Blood sampling at 15, 20, 25, 30, 40, 50, 60, 120, and 180 minutes after the first drop instillation.
Pharmacokinetic profile of phenylephrine: maximum (peak) whole blood concentration (Cmax).
Each participant will be sampled once (random allocation to one time-point). Blood sampling will be combined with peripheral blood collection for routine examinations.
Time frame: Blood sampling at 15, 20, 25, 30, 40, 50, 60, 120, and 180 minutes after the first drop instillation.
Pharmacokinetic profile of phenylephrine: time to reach maximum (peak) whole blood concentration (Tmax).
Each participant will be sampled once (random allocation to one time-point). Blood sampling will be combined with peripheral blood collection for routine examinations.
Time frame: Blood sampling at 15, 20, 25, 30, 40, 50, 60, 120, and 180 minutes after the first drop instillation.
Pharmacokinetic profile of phenylephrine: elimination half-life (T1/2).
Each participant will be sampled once (random allocation to one time-point). Blood sampling will be combined with peripheral blood collection for routine examinations.
Time frame: Blood sampling at 15, 20, 25, 30, 40, 50, 60, 120, and 180 minutes after the first drop instillation.
Heart rate values (beats per minute).
Time frame: 45, 90 and 120 minutes after the first drop instillation.
Oxygen saturation (SpO2) values (%).
Time frame: 45, 90 and 120 minutes after the first drop instillation.
Systolic, diastolic, and mean blood pressure values (mmHg).
Time frame: 45, 90 and 120 minutes after the first drop instillation. Hourly blood pressure measurements for the first 24 hours after mydriasis.
Number of participants with systemic adverse events.
Apnea, increased gastric residuals, inhibited duodenal motor activity, delayed gastric emptying, feeding intolerance, abdominal distension, vomiting, paralytic ileus, acute gastric dilatation, necrotizing enterocolitis (NEC).
Time frame: During the 48 hours after mydriasis.
Number of participants with local adverse events.
Periorbital pallor, eyelid swelling, flushing.
Time frame: 45 minutes after the first drop instillation.
Adequacy of judging the presence or absence of treatment-requiring ROP.
Time frame: At the end of the eye examination (fundoscopy).
Plan to share: Yes — Deidentified Individual Participant Data (IPD) that underline published results, along with related data dictionaries, will be available from 3 months to 36 months following article publication, only to researchers who will provide a methodologically sound proposal, for types of analyses to achieve aims in the approved proposal or for individual participant data meta-analysis, and only after acceptance of the proposed protocol by our Institution's IRB. Proposals should be directed to the corresponding author (AM, amatafts@auth.gr) and data requestors will need to sign a data access agreement. The study protocol and statistical analysis plan will also be available, if needed.
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Aristotle University Of Thessaloniki