Development of a new grading scale for tear ferning

Area of Science:

• Ophthalmology
• Optometry
• Biomedical Engineering

Background:

• Tear ferning (TF) is a diagnostic method used to assess dry eye disease.
• Existing grading scales, such as the Rolando scale, may have limitations in discriminating between different TF patterns.

Purpose of the Study:

• To develop a novel subjective grading scale for tear ferning patterns.
• To compare the diagnostic performance of the new scale against the established Rolando scale.

Main Methods:

• A library of TF patterns from normal and dry eye subjects was curated.
• Optometrists ranked TF images, leading to the identification of homogeneous subsets.
• A new 7-point scale was developed and tested, with subsequent refinement to a 5-point scale.

Main Results:

• The Rolando scale identified 3 homogeneous subsets of TF patterns.
• The newly developed 7-point scale initially identified 5 subsets.
• A refined 5-point TF grading scale (Grades 0-4) was established.

Conclusions:

• The Rolando scale exhibits limited discriminatory power, particularly between Type I and II grades, impacting its reliability.
• The new 5-point TF grading scale demonstrates enhanced ability to differentiate TF patterns.
• This improved scale offers potential benefits for both research and clinical applications in dry eye diagnosis.