An evaluation of the efficacy of fluorescein, rose bengal, lissamine green, and a new dye mixture for ocular surface staining

Abstract

Purpose: Sodium fluorescein is considered the premier dye for corneal staining and, similarly, rose bengal (RB) for conjunctival staining. A mixture of 1% fluorescein and 1% rose bengal has been reported as advantageous in daily practice. Mixtures of lissamine green with other ocular stains have not been reported. The purposes of this study were to review the clinical staining characteristics of fluorescein, rose bengal, and lissamine green in controlled dose and concentration and determine whether optimal staining of the cornea and bulbar conjunctiva are possible by using dye mixtures.

Methods: Sixteen 10-microL solutions of fluorescein, rose bengal, lissamine green, and their mixtures were evaluated. Fourteen subjects with a diagnosis of dry eye were tested for staining with various combinations of the dyes. Examination of staining was made by using standard clinical practices.

Results: A mixture of 2% fluorescein and 1% rose bengal was the most efficacious staining mixture for the cornea and conjunctiva, but moderate to marked discomfort was reported. The mixture of 2% fluorescein and 1% lissamine green did not result in discomfort and provided optimal corneal and conjunctival staining with only slightly less efficacy than 2% fluorescein and 1% rose bengal; 2% and 3% lissamine green produced burning and discomfort. The fluorescent characteristics of fluorescein were not significantly altered by the addition of 1% lissamine green. The preferred mixture for simultaneous and efficacious staining of the cornea and conjunctiva without an adverse sensation was 2% fluorescein and 1% lissamine green.

Conclusions: A mixture of 2% fluorescein and 1% lissamine green offers excellent simultaneous corneal and bulbar conjunctival staining and could replace the use of individual dyes for ocular staining and contact lens practice.