Lissamine green, staining patterns vital to early diagnosis of dry eye

Dallas-A few properly placed drops of lissamine green can reveal staining patterns that are key to diagnosing dry-eye syndrome earlier than possible with other methods, according to new research from the University of Texas Southwestern Medical Center.

“What this research showed is that the degree and pattern of staining was a good, objective indicator of the severity of the tear deficiency,” said James McCulley, MD, chairman of ophthalmology at the institution and senior author of the study.

In an article published in the July issue of Eye and Contact Lens (33[4]:177-179), he and colleagues identified three basic patterns indicating progressively dangerous conditions:
• The least severe condition is indicated by stains limited to the white of the eye between the lids toward the nose. This so-called nasal staining doesn’t necessarily predict dry eye; it might be caused by environmental factors, such as pollution.
• The second level appears as stains in the white of the eye between the lids but toward the ear.
• The third and most severe level occurs when the stain also appears on the cornea, indicating a break in the surface cells where bacteria can penetrate.

Researchers examined the stain patterns in 22 patients with varying degrees of dry eye and in 11 patients without ocular disease, who served as control subjects. In addition to revealing the progressive pattern, the research also underscored the value of using lissamine green stain instead of the more commonly used fluorescein stain, which does not easily identify damage until it is more progressed.

“If an ophthalmologist uses the most commonly used stain, which is fluorescein, [then he or she is] going to miss the first two stages of the development of dry eye and, consequently, miss a lot of diagnoses,” said Dr. McCulley, also director of the Theodore and Mary Beasley Laboratory for Ocular Surface Research and the Jean H. & John T. Walter Jr. Center for Research in Age-Related Macular Degeneration.

Early diagnosis of dry eye is important because more treatment options are available in the beginning stages of the syndrome, further progression of the disease can be prevented, and other conditions signaled by dry eye, such as lupus or rheumatoid arthritis, can be identified sooner.

Grants from the National Institutes of Health and Research to Prevent Blindness funded the study.