The purpose of this study is to compare the mydriatic effect of 2.5% phenylephrine and 1% tropicamide by conventional instillation and lower conjunctival fornix packing in premature infants.

Adequate pupil dilatation was needed for screening and treatment of retinopathy of prematurity (ROP) in premature infants.In general clinical practice, mydriatic drugs were instilled many times until the pupil reached the maximum size. However, poor mydriasis were found in many eyes despite maximum instillation was used. From the clinical observation, we found the packing of mydriatic drugs in lower conjunctival fornix was much more effective to dilate the pupil than instillation in some patients. The purpose of this study was to compare the mydriatic effect of 2.5% phenylephrine and 1% tropicamide by conventional instillation and lower conjunctival fornix packing in premature infants.

Inclusion Criteria:

• gestational age of less than 32 weeks and/or the birth weight of less than 1,500 grams
• stable clinical course

Exclusion Criteria:

• history of intraocular surgery or laser treatment
• previous eyedrop instillation that might affect the pupil size
• severe underlying disease or unstable clinical course that mydriatic drugs or the examination could aggravate their conditions