[Causes and incidence of short-life keratitis caused by dacryography. Optimization of protective parameters]

This study was aimed at investigating the changes occurring in superficial corneal epithelium (localized or diffuse, dotted or linear) as observed in 300 eyes after macrodacryography with iodate contrast media (iodized oil and water soluble non-ionic agents). In our opinion, the causes of iatrogenic short-life keratitis are: needle injury, the deposition of iodate contrast medium on the cornea and the reduction of palpebral winking, favoring dry eye, due to superficial anesthesia. The pharmacologic protection of the cornea by means of high-viscosity drugs allows both the number and the degree of keratitis to be markedly reduced. Therefore, contrast media must be chosen on the basis of anamnestic and clinical data, as well as of patient's symptoms, focusing mainly on the characteristics of the various agents--i.e., density, concentration, viscosity.