Evaluation of the lacrimal drainage function by the drop test

Area of Science:

• Ophthalmology
• Ocular Surface Disease
• Tear Film Dynamics

Background:

• Assessing lacrimal drainage capacity is crucial for diagnosing and managing epiphora.
• Current methods like the fluorescein dye disappearance test have limitations in sensitivity and quantification.
• A need exists for a more precise and reliable test to evaluate tear outflow.

Purpose of the Study:

• To compare the diagnostic accuracy of the fluorescein dye disappearance test with a novel drop test for evaluating lacrimal drainage capacity.
• To determine the sensitivity and quantitative capabilities of the new drop test.

Main Methods:

• The fluorescein dye disappearance test involved instilling fluorescein into the conjunctival sac and measuring fluorescence decay.
• The new drop test involved instilling saline solution and measuring the volume drained over three minutes.
• Both tests were performed on normal subjects and patients with varying degrees of epiphora.

Main Results:

• The fluorescein dye disappearance test showed reduced values in patients with epiphora but could not differentiate severity.
• The drop test demonstrated a decrease in lacrimal drainage capacity with age in normal subjects.
• The drop test revealed significant reductions in drainage even with minor epiphora and showed a clear correlation with symptom severity.

Conclusions:

• The drop test provides a quantitative measure of lacrimal drainage function.
• The drop test is more sensitive than the fluorescein dye disappearance test in detecting impaired tear outflow.
• The drop test is a valuable tool for assessing lacrimal drainage, particularly in cases of mild epiphora.