Aqueous-Deficient Dry Eye Increases Lipid Layer Thickness Measured by Dynamic Tear Interferometry

Area of Science:

• Ophthalmology
• Dry Eye Disease Research
• Tear Film Dynamics

Background:

• Dry eye disease (DED) is a prevalent condition affecting millions worldwide.
• Aqueous-deficient dry eye (ADDE) is a subtype characterized by insufficient tear production.
• Accurate measurement of tear film lipid layer thickness (LLT) is crucial for diagnosing and managing DED.

Purpose of the Study:

• To investigate the impact of aqueous deficiency on lipid layer thickness (LLT) measurement in dry eye disease.
• To evaluate changes in LLT before and after treatment for aqueous-deficient dry eye (ADDE).
• To assess the relationship between LLT and tear film lipid layer (TFLL) dynamics using dynamic tear interferometry.

Main Methods:

• A prospective comparative study involving 230 patients with ADDE.
• Comparison between a treatment group (punctal plug insertion) and a control group.
• Measurement of average LLT (LLT ave ) using LipiView II at baseline and 1 month, with correlation analyses with TFLL indices.

Main Results:

• Baseline LLT ave was elevated in both groups (116.1 ± 26.7 nm and 112.3 ± 27.6 nm).
• LLT ave significantly decreased in the treatment group after 1 month (-41.8 nm, P = 0.003).
• LLT ave was negatively correlated with tear meniscus height (TMH) and positively with TFLL spreading time and deviation.

Conclusions:

• In ADDE, the tear film lipid layer (TFLL) is thicker than normal (60-99 nm) and thins with treatment.
• LLT is influenced by both meibum secretion and aqueous status.
• Changes in TFLL dynamics play a significant role in LLT variations in ADDE.