DOWNLOADS
Carnt NA et al. The IER Matrix Study. Contact Lens Spectrum 2007

www.staininggrid.com. Accessed in January 2008

Dillehay SM & Cutter G. A Statistical Analysis of the Staining Grid. Contact Lens Spectrum, November 2007

Snyder C. Solution Interaction with the Ocular Surface: The Significance in Making the Grade. Clinical & Refractive Optometry, 2005; 16:5, 134-140. Copyright Mediconcept 2005.

The Andrasko staining grid
The colour-coded corneal staining grid developed by optometrists, Dr. Gary Andrasko, and Dr. Kelly Ryen with support from Alcon has borne much industry discussion and debate. Specifically around the importance and clinical relevance of statistically significant differences in graded staining.1 The "Andrasko Grid", developed as a reference guide for eye care practitioners to gauge the level of biocompatibility of various contact lens/ multipurpose solutions,1 provoked many questions, including one so fundamental as 'does this data have any statistical or clinical relevance?'1

The fundamental question
Scientific validation through robust clinical trial methodology and statistical analysis is fundamental to confirming a clinical outcome.1 In contemplating the methodology used to develop the Andrasko grid, consider current grading scales, standards for acceptable levels of corneal staining and definitions of clinical significance before giving credence to the findings of Dr. Andrasko.

How useful are these findings?

Internationally accepted clinically significant staining is Grade = 3 coalescent macropunctate4
The Andrasko grid shows that most lens/lens care surface area percentage values represent clinically insignificant Grade 1 micropunctate or Grade 2 macropunctate4
Superficial, transient corneal staining occurs in lens and non-lens wearers and based on scientific data, is not a risk factor for lens related corneal infection5

A number of experts have commented in response to the colour-coded corneal staining grid

'Some of the conclusions may bring about unwarranted fear about corneal staining for patients. History shows that medical scares are nothing new' Milton Hom, OD, FAAO2

'Beyond the stated hypothesis, we must also look at the science behind any given study and its execution to determine its validity' Paul M Karpecki, OD3

'A non-validated instrument such as the 'staining grid' is clearly misleading in terms of risk assessment, as the color coding suggests, and misrepresents the relative risk of a medical device that has been shown to be one of the safest devices in use today' Brian Levy, OD, M.Sc, FAAO4

'We believe the Andrasko and Ryen color-coded staining grid has blinded many practitioners to the reality of the actual implications of the results of their work. The color coding has led many practitioners to believe that there is substantial product differences in cases where none exist, and that there aren't any substantial differences where some do exist.' Dillehay S OD, EdD Long BS, MBA & Cutter G Phd1

'We believe using the grid for assignment of risk is inconsistent with standard measures and is in fact misleading' Levy B, OD, MSc, FAAO & Orsborn G, OD, MSc, FAAO5

References

  1. Dillehay SM et al. A Statistical Analysis of the Staining Grid. Contact Lens Spectrum, November 2007
  2. Carnt NA et al. The IER Matrix Study. Contact Lens Spectrum 2007
  3. www.staininggrid.com. Accessed in January 2008
  4. Snyder C. Solution Interaction with the Ocular Surface: The Significance in Making the Grade. Clinical & Refractive Optometry, 2005; 16:5, 134-140. Copyright Mediconcept 2005.
  5. Levy B & Orsborn G. Clinical Risks: Myths and Truths. Interpreting the evidence-based data about contact lens care. Contact Lens Spectrum, January 2008.
  6. Hom M. The New Math of Corneal Staining. Contact Lens Spectrum, March 2007; 44-46
  7. Karpecki P. Much Ado about Staining. Review of Optometry, November 2006; 135-136
  8. Levy B. Infectious Keratitis: What have we Learned? Eye & Contact Lens, August 2007; 33(6):1-1

www.truthaboutstaininggrid.com is intended as a scientific resource for eye care practitioners developed by Bausch & Lomb