Separate and additive mydriatic effects of lidocaine hydrochloride, phenylephrine, and cyclopentolate after intracameral injection.

PURPOSE

To assess the separate mydriatic effect of lidocaine hydrochloride (Xylocaine), cyclopentolate, and phenylephrine after intracameral injection and evaluate whether intracameral Xylocaine and phenylephrine without cyclopentolate provide sufficient pupil dilation for cataract surgery.

SETTING

Department of Clinical Science/Ophthalmology, Umeå University Hospital, Umeå, Sweden.

METHODS

This prospective randomized double-masked study included 56 patients with age-related cataract scheduled for unilateral phacoemulsification. In 16 patients, Xylocaine 1%, phenylephrine 1.5%, and cyclopentolate 0.1% were injected one after the other. Phenylephrine and cyclopentolate were randomized to switch in order, creating 2 study groups. An additional 40 patients were randomized to receive intracameral Xylocaine 1%, phenylephrine 1.5%, and cyclopentolate 0.1% or intracameral Xylocaine 1% and phenylephrine 1.5% only.

RESULTS

Xylocaine alone caused significant pupil dilation (mean 4.9 +/- 0.6 mm). In the group in which cyclopentolate was injected next, the pupil size increased 1.3 +/- 0.6 mm (P<.001). When phenylephrine was added, the pupil increased an additional 0.7 +/- 0.4 mm (P = .003). In the second group, in which phenylephrine was the second injection, the pupil size increased 2.1 +/- 0.5 mm (P<.001). When cyclopentolate was added, no significant change in size occurred. No statistically significant differences in pupil size were observed between the 40 patients who were given intracameral mydriatics with or without cyclopentolate.

CONCLUSIONS

Xylocaine plus phenylephrine injected intracamerally gave adequate intraoperative pupil dilation in routine phacoemulsification surgery. Cyclopentolate administrated intracamerally had no immediate additive mydriatic effect to intracameral Xylocaine combined with phenylephrine.