Evaluation of a new preoperative ophthalmic solution.

BACKGROUND

Maximum mydriasis and corneal clarity during intraocular surgery are important to ensure operational safety. However, repeated instillation of mydriatic and anti-inflammatory ophthalmic solutions during surgery may affect compliance and may damage the corneal epithelium. We developed an ophthalmic solution containing tropicamide, phenylephrine hydrochloride and diclofenac sodium, and compared the properties and effect on corneal epithelial barrier function and on mydriasis of the solution and of its individual components.

METHODS

We developed the ophthalmic solution by mixing 10 mL of 0.5% tropicamide/0.5% phenylephrine, 10 mL of 5% phenylephrine and 10 mL of 0.1% diclofenac (TPD). We determined the stability of the chemicals in solution using high-performance liquid chromatography immediately, 1 week and 1 month after mixing. Corneal epithelial barrier function was assessed before and after instillation of the solutions in 26 eyes of 17 patients (5 with proliferative diabetic retinopathy or diabetic maculopathy, 8 with cataract and 4 with no eye disease). The fluorescent intensity was measured 10 times at the central cornea 30 minutes after instillation of 3 mL of 0.5% fluorescein solution and the average value calculated. Finally, the pupil diameter of 50 eyes of 38 patients undergoing cataract surgery was measured before and immediately after the operation.

RESULTS

No remarkable changes in the pH or pharmacologic activity of the TPD solution were observed at any time after mixing. In the patients with diabetic retinopathy or cataract, the increase in mean fluorescent intensity was significantly greater with the individual solutions than with the TPD solution (p < 0.01); there was no significant difference in mean fluorescent intensity in the subjects with no eye disease. No statistically significant difference in pupil diameter was observed between the eyes that received the TPD solution and those that received the individual solutions.

INTERPRETATION

TPD ophthalmic solution is simple to prepare and use. The TPD solution had a similar effect on mydriasis as the three individual solutions but was less destructive to the corneal epithelium.