Comparison of the effectiveness of mydriasis by two instillation methods of combined 0.75% tropicamide and 2.5% phenylephrine eye drop in preterm infants.
OBJECTIVE
To compare the effectiveness and safety of two instillation methods of combined 0.75% tropicamide and 2.5% phenylephrine at 0, 5 minutes (min) with the same combined regimen at 0,30 minutes in preterm infants.


METHODS
A prospective, cross-over, randomized controlled trial was performed to compare 0, 5-min instillation (Method A) of combined 0.75% tropicamide and 2.5% phenylephrine with 0, 30-min instillation (Method B) of the same regimen. Forty-two preterm infants scheduled for screening retinopathy of prematurity (ROP) were randomly assigned to two groups. Group 1 was defined as preterms applied by Method A at first examination then by Method B 1-4 weeks apart whereas vice versa in Group 2. Pupil size, heart rate (HR), systolic and diastolic blood pressure (SBP, DBP) were recorded before and after eye-drop instillation.


RESULTS
Mean time to 7-mm pupil size was no statistically significant difference between the two methods (Method A 46.47 min, Method B 46.58 min; p = 0.894). Method B has mean longer time to maintain 7-mm pupil size than Method A (Method A 67.67 min, Method B 75.33 min); but not statistically significant different (p = 0.323). HR, SBP and DBP were not significant change between the two methods.


CONCLUSIONS
Both instillation methods produced consistently sufficient mydriasis and safety for evaluation peripheral fundus. Method B has slight longer mydriatic effect than Method A; thus giving more time to evaluate infant's eye for ophthalmologists.
Department of Ophthalmology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand. pittaya2002@gmail.com
Pittaya
P
Phamonvaechavan
Kanya
K
Chutasmit
Parichat
P
Damrongrak
Supanna
S
Koukiatkul
Tassanee
T
Wongkiatkajorn
Sopapan
S
Ngerncham
D018592:Cross-Over Studies; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007322:Instillation, Drug; D008297:Male; D009184:Mydriatics / Q000008:administration & dosage*; D015997:Neonatal Screening; D010656:Phenylephrine / Q000008:administration & dosage*; D011680:Pupil / Q000187:drug effects*; D012178:Retinopathy of Prematurity / Q000175:diagnosis*; D014331:Tropicamide / Q000008:administration & dosage*
D009184:Mydriatics; D010656:Phenylephrine; D014331:Tropicamide