Cycloplegic effect of 0.5% tropicamide and 0.5% phenylephrine mixed eye drops: objective assessment in Japanese schoolchildren with myopia.
OBJECTIVE
To evaluate the cycloplegic effect of mixed eye drops containing 0.5% tropicamide and 0.5% phenylephrine in myopic children, and to determine whether their efficacy was associated with their clinical characteristics.


METHODS
Eighty-one myopic children (age, mean +/- SD, 11.0 +/- 1.5 years; mean spherical equivalent refractive error, -4.27 +/- 1.41 D; range, -1.57 to -8.66 D) were recruited. One drop of Mydrin-P was administered to each eye twice, with an interval of 5 min between. Twenty-five minutes after the second drop, accommodative responses were measured with an open-view autorefractometer, while the subject was encouraged to accommodate by binocularly looking at a Maltese cross located at a distance of 33 cm. The difference between the refractive reading and that obtained with a Maltese cross at 500 cm was regarded as residual accommodation (RA). The repeatability of this measurement was also evaluated.


RESULTS
The mean RA was 0.21 +/- 0.29 D (range, -0.31 to 0.99 D). There was no association in RA between the right and left eyes, between RA and age, or between RA and sex, but RA was weakly correlated with refractive error (r = 0.274, P = 0.019). The intersubject difference found in RA can be explained mostly by the extent of repeatability (+/-0.71 D).


CONCLUSIONS
The insignificant magnitude of RA indicated that the mixed eye drop is an acceptable and useful cycloplegic agent in Japanese schoolchildren with a wide range of myopic refractive errors.
Hamasaki
Ichiro
I
Department of Ophthalmology, Okayama University, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
Hasebe
Satoshi
S
Kimura
Shuhei
S
Miyata
Manabu
M
Ohtsuki
Hiroshi
H
D000065:Accommodation, Ocular / Q000187:drug effects*; D000293:Adolescent; D044466:Asian People; D002648:Child; D002924:Ciliary Body / Q000187:drug effects; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D009184:Mydriatics / Q000008:administration & dosage*; D009216:Myopia / Q000150:complications* / Q000208:ethnology; D009883:Ophthalmic Solutions / Q000008:administration & dosage*; D010656:Phenylephrine / Q000008:administration & dosage*; D011680:Pupil / Q000187:drug effects; D012029:Refraction, Ocular; D014331:Tropicamide / Q000008:administration & dosage*
D009184:Mydriatics; D009883:Ophthalmic Solutions; D010656:Phenylephrine; D014331:Tropicamide