Aligning the Goldmann tonometer tip by means of the "precontact whitish rings"

A set of whitish rings observed before contact is made during Goldmann-type applanation tonometry can help simplify and speed the examination. The ori entation and size of the rings are useful both in aligning the tonometer an d in estimating the distance remaining before contact is made. Relying on t hese whitish rings can also avoid some of the shear-related damage exerted on the corneal epithelium from alignment movements of the tonometer tip aft er contact with the cornea has been made. (C) 1999 by Elsevier Science Inc. All rights reserved.