An improved method for the delivery of artificial tears using an infusion pump.

Patients with markedly decreased or absent tear duct production require the frequent instillation of artificial tear preparations. Through animal experiments, a new method has been developed for the continuous infusion of these solutions. In this procedure, the canalicular system is intubated with fenestrated silastic tubing, which is subcutaneously tunnelled and then attached to a miniaturized and computerized pumping device. This makes it possible for a predetermined volume of solution to be automatically and continuously delivered. Using this technique, artificial tear solution was instilled at a rate of 1.75 microliter/min, a rate approximately the normal basic tear secretion rate (0.5-2.2 microliters/min). This resulted in a 14% increase in tear flow from preoperative values. This represents a 74% increase in tear secretion rates for patients with keratoconjunctivitis sicca. None of the experimental animals developed subcutaneous infections, dacryocystitis, or corneal ulcers. By utilizing the normal anatomy of the lacrimal drainage system, this new technique: does not compromise the conjunctival cul-de-sac or the salivary system, avoids the inconvenience of previous external devices, and allows for the automatic instillation of predetermined volumes of artificial tear solutions.