New Software Application for Clarifying Tear Film Lipid Layer Patterns

Abstract

The lipid layer of the tear film limits evaporation during the interblink interval and also affects tear stability. This study was designed to validate a new software application designed to characterize the tear film lipid layer through texture and color pattern recognition. Using the Tearscope-plus (slit-lamp magnification ×200), the lipid layer was examined in 105 healthy young adults, and interference photographs were acquired with a Topcon DV-3 digital camera. The photographs were classified by a clinician experienced in examining lipid layer patterns (LLPs), and these classifications were used as the reference standard (reference examiner). Next, LLPs were graded using the new software and further by 2 observers (observer 1 and observer 2) with experience in examining the ocular surface. Strong correlation was detected between the categories determined by the new application and reference examiner (Cramer V 0.85-0.93, P < 0.001). The classifications made using the new application and by observer 1 and observer 2 were also consistent although correlation was weaker (Cramer V 0.56-0.87, P < 0.001). For thinner LLPs, greatest correspondence with the reference was observed using the new software (96.6%), whereas the 2 observers showed better agreement when grading thicker patterns. Notwithstanding, agreement between the 2 observers and the reference examiner was good with at least 81% matched classifications. Best agreement (96.2%) was noted between the new method and observers 1 and 2 for recognizing meshwork patterns, whereas observers 1 and 2 showed greatest correspondence when classifying color fringe patterns. The new application can objectively categorize LLPs using the Tearscope-plus.