Sir,

We congratulate Tinley and Bates on their excellent safety study on the use of intracameral phenylephrine (PE). Ideally, a drug that is intended for intracameral use should be free of any preservative, but when this is not available, as in our study, a safe and practical alternative must be sought.

The exposure time of intracameral PE is seconds between the instillation of the drug and the injection of viscoelastic. It is extremely unlikely that even the slightly acidic PE solution would cause any endothelial damage. It would be very difficult to quantify the endothelial cell damage as the drug is used just before a surgical procedure that is known to induce endothelial cell loss.

Tinley and Bates have established that our preparation is indeed a safe and viable drug to use in the eye, especially with the low concentration that we have recommended. Until a preservative free PE is available, we continue to recommend our preparation.