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Lower conjunctival fornix packing for mydriasis in premature infants: a randomized trial
Onsiri Thanathanee1, Tanapat Ratanapakorn, Michael G Morley
1Department of Ophthalmology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
Insights
Lower conjunctival fornix packing with phenylephrine and tropicamide achieved significantly greater pupil dilation than conventional eyedrop instillation in premature infants. This packing method is recommended for difficult-to-dilate preterm infant pupils.
Area of Science:
- Ophthalmology
- Neonatal Medicine
Background:
- Ophthalmological examinations in premature infants, particularly for retinopathy of prematurity, require adequate pupil dilation.
- Conventional eyedrop instillation of mydriatics can sometimes be insufficient for achieving optimal dilation in this population.
Purpose of the Study:
- To compare the efficacy of lower conjunctival fornix packing versus conventional eyedrop instillation for mydriasis in premature infants.
- To evaluate the mydriatic effect of phenylephrine 2.5% and tropicamide 1% using two different administration methods.
Main Methods:
- A randomized study comparing lower conjunctival fornix packing with conventional eyedrop instillation of phenylephrine 2.5% and tropicamide 1% in premature infants.
- Pupil diameter was measured 40 minutes post-administration.
- Each infant received one method in one eye and the alternate method in the fellow eye.
Main Results:
- The mean dilated pupil diameter was significantly larger with the lower conjunctival fornix packing method (5.76 ± 1.01 mm) compared to conventional instillation (4.50 ± 1.08 mm).
- The difference in pupil diameter between the two methods was statistically significant (P < 0.05).
Conclusions:
- Lower conjunctival fornix packing provides superior pupil dilation compared to conventional eyedrop instillation in premature infants.
- The packing method is recommended for dilating preterm infant pupils, especially in cases where dilation is challenging.
Objective:
To compare the mydriatic effect of lower conjunctival fornix packing to conventional instillation of eyedrops containing 2.5% phenylephrine and 1% tropicamide in premature infants undergoing examination for retinopathy of prematurity.
Methods:
The patients were randomized to receive either conventional instillation of mydriatic drops or lower conjunctival fornix packing in one eye and the alternate method in the fellow eye. For the eyes receiving lower conjunctival fornix packing (study group), one small piece of the cotton wool soaked with one drop of 2.5% phenylephrine and one drop of 1% tropicamide was packed in the lower conjunctival fornix for 15 minutes. For the eyes receiving the conventional instillation (control group), 2.5% phenylephrine and 1% tropicamide were alternately instilled every 5 minutes for two doses each. Horizontal pupil diameter was measured with a ruler in millimeters 40 minutes later.
Results:
The mean dilated pupil diameter in study group and control group were 5.76 ± 1.01 mm and 4.50 ± 1.08 mm, respectively. This difference was statistically significant (P < 0.05).
Conclusion:
The dilated pupil diameter after receiving the lower conjunctival fornix packing was larger than conventional instillation with a statistically significant difference. We recommended the packing method to dilate the preterm infant pupil, especially if the pupil is difficult to dilate.
