A concise breakdown of the key points from the MyMiROPS Randomized Clinical Trial published in JAMA Ophthalmology (2025) on mydriatic microdrops for retinopathy of prematurity (ROP) screening:
🧪 Study Purpose
- Goal: Test whether microdrops (6.5 μL) of 1.67% phenylephrine + 0.33% tropicamide are noninferior to standard drops (28–34 μL) for pupil dilation in preterm infants during ROP screening.
- Also assessed safety (cardiorespiratory & gastrointestinal adverse events) and systemic absorption of phenylephrine.
🏥 Design & Participants
- Type: Double-masked, noninferiority, crossover randomized clinical trial.
- Setting: Tertiary neonatal center in Northern Greece (Sept 2021–Jan 2023).
- Participants: 83 preterm infants (<32 weeks gestation and/or <1501 g birthweight, or with comorbidities).
💡 Intervention
- Each infant received both microdrops and standard drops in random order, with a 1-week washout.
- Pupil size measured at 45 min (primary), 90 min, and 120 min after instillation.
📊 Main Findings
Efficacy
- 45 min: Microdrops superior to standard drops (mean diff +0.12 mm).
- 90 & 120 min: Microdrops noninferior.
- All exams achieved adequate dilation for ROP assessment.
Safety
- Oxygen saturation: Lower after standard drops at 45 and 90 min.
- Blood pressure: Higher percentage of 24-hour hypertensive episodes after standard drops.
- Adverse events: Trend toward fewer 48-hour systemic events with microdrops (not statistically significant).
- No eyelid swelling or flushing; periorbital pallor common in both groups.
Pharmacokinetics
- Phenylephrine blood levels variable; both methods produced similar systemic exposure over 3 hours.
- Half-life ~53 minutes; standard drops had slightly faster absorption.
📌 Conclusions
- Microdrops are noninferior to standard drops for mydriasis in preterm infants and may have a better safety profile.
- Potential to reduce systemic side effects in a vulnerable population.
- First study to define phenylephrine pharmacokinetics in this group.
🔍 Implications
- Supports adopting microdrops in NICUs for ROP screening.
- Calls for further research in other regimens, populations, and longer-term systemic exposure.
Here’s the side-by-side comparison of microdrops vs standard drops from the MyMiROPS trial, so you can see the differences in efficacy, safety, and pharmacokinetics at a glance:
📊 Microdrops vs. Standard Drops in ROP Screening
| Category | Microdrops (6.5 μL) | Standard Drops (28–34 μL) | Key Takeaway |
|---|---|---|---|
| Mydriatic efficacy | 45 min: 6.17 mm (superior, +0.12 mm)<br>90 min: 6.09 mm (noninferior)<br>120 min: 5.73 mm (noninferior) | 45 min: 6.05 mm<br>90 min: 6.06 mm<br>120 min: 5.76 mm | Microdrops achieve equal or better dilation, especially at 45 min (primary exam time). |
| Adequacy for ROP exam | 100% adequate visualization | 100% adequate visualization | Both regimens sufficient for screening. |
| Oxygen saturation (SpO₂) | Higher at 45 & 90 min | Lower at 45 & 90 min (−0.66% and −0.58%, both significant) | Microdrops may reduce transient desaturation risk. |
| 24‑h hypertensive episodes | Median 0.10% | Median 0.14% (P = .01) | Standard drops linked to more BP spikes over 24 h. |
| 48‑h systemic adverse events | Trend toward fewer events (OR 1.0 baseline) | 41% higher odds of events (OR 1.41, NS) | Microdrops show a better safety trend. |
| Local adverse events | Periorbital pallor in 53% | Periorbital pallor in 60% | No swelling or flushing in either group. |
| Phenylephrine pharmacokinetics |
Half-life: 53 min Peak conc.: 5.45 ng/mL at 55 min AUC₁₈₀: 658 ng·min/mL |
Half-life: 53 min Peak conc.: 5.03 ng/mL at 37 min AUC₁₈₀: 512 ng·min/mL |
Similar systemic exposure; standard drops absorbed slightly faster. |
| Relative bioavailability | Reference | 116% vs microdrops | Standard drops deliver slightly more systemic phenylephrine overall. |
🔍 Interpretation
- Efficacy: Microdrops are noninferior overall and superior at the key 45‑minute mark.
- Safety: Microdrops show fewer oxygen desaturations, fewer hypertensive episodes, and a trend toward fewer systemic adverse events.
- Pharmacokinetics: Despite the smaller dose, systemic phenylephrine exposure is similar — suggesting efficient ocular absorption.
Seliniotaki, A. K., Lithoxopoulou, M., Virgiliou, C., Gika, H., Dokoumetzidis, A., Bougioukas, K. I., Raikos, N., Diamanti, E., Ziakas, N., Haidich, A.-B., & Mataftsi, A. (2025). Efficacy and safety of mydriatic microdrops for retinopathy of prematurity screening: The MyMiROPS randomized clinical trial. JAMA Ophthalmology, 143(2), 110–116. https://doi.org/10.1001/jamaophthalmol.2024.5462
