Article Date: 7/1/2010

Online Photo Diagnosis

Online Photo Diagnosis

By William Townsend, OD, FAAO

The patient whose eye is pictured suffers from severe aqueous tear layer deficiency and meibomian gland dysfunction. Upon presentation, her case history strongly suggested dry eye disease. This initial diagnosis was confirmed with Schirmer (without anesthesia) testing, meibomian gland expression/transillumination, and vital staining of the cornea and conjunctiva with lissamine green.

In 1933, Sjögren described rose bengal staining in individuals who had keratoconjunctivitis sicca syndrome. Feenstra and Tseng (1992) established that cells that stain with rose bengal have lost their protective mucin coating. Machado et al (2009) showed that in patients who have dry eye syndrome, rose bengal and lissamine green demonstrate virtually identical staining characteristics. Lissamine green does not cause the high levels of irritation experienced by patients who are exposed to comparable concentrations of rose bengal.

Lissamine green is very useful in the diagnosis and management of dry eye conditions, but it does have limitations. Korb et al (2008) evaluated staining efficacy of vital dyes on the ocular surface. They found that while lissamine green and rose bengal are good for conjunctival staining, they do not stain corneal tissue well. Conversely, sodium fluorescein stains corneal tissue well, but is a marginally effective agent for staining conjunctiva. They reported optimal staining of both tissues with a combination of 2% fluorescein and 1% lissamine green.

In our practice, we find it beneficial to use vital dyes compounded in sterile form and packaged in 3mm syringes. Each syringe is tipped with a micro filter that effectively prevents contamination of the drops by bacteria or viruses. It eliminates the need to use strips that must be wetted with saline and therefore may not necessarily deliver a consistent concentration with each application. The syringe technology allows us to rapidly deliver the agent to the ocular surface at a consistent concentration every time we stain the eye.

Lissamine green staining is a valuable tool in diagnosing and managing ocular surface disease. Consider using it in conjunction with fluorescein to optimally stain and detect effects in the corneal and conjunctival surfaces.

References



Contact Lens Spectrum, Issue: July 2010