Abstract
Purpose:
It is considered that tear film instability and increased friction during blinking are related to the pathophysiology of aqueous tear deficient dry eye. Punctal occlusion increases the tear volume on the ocular surface and is considered to improve both tear film instability- and increased friction-related mechanisms. The purpose of this present study was to investigate the effect of punctal occlusion on those mechanisms.
Methods:
This study involved 13 eyes of 13 patients with aqueous tear deficient dry eye (mean age: 70.8 years). In all eyes, dry-eye-related symptoms were evaluated by use of a visual analog scale (VAS, mm), and tear meniscus radius (TMR, mm), interference grade/spread grade (IG/SG) of the tear-film lipid layer (i.e., IG/SG 1-5: 1 being the best), non-invasive breakup time (NIBUT, seconds), fluorescein breakup time (FBUT, seconds), ocular surface epithelial damage score (OSED, cornea: 15 points maximum, conjunctiva: 6 points maximum), corneal filament grade (CFG: 3 points maximum), lid-wiper epitheliopathy grade (LG: 6 points maximum) and superior limbic keratoconjunctivitis grade (3 points maximum) were evaluated before and at more than 1-month post punctal occlusion . The Schirmer 1 test (ST1, mm) was measured only before punctal occlusion. The change of each factor pre and post punctal occlusion were then investigated.
Results:
Post punctal occlusion, VAS-related subjective symptoms including “dryness”, “difficulty in opening the eye”, “foreign body sensation”, “pain”, “redness”, “blurred vision”, “sensitivity to light”, “heavy eyelid”, and “eye fatigue” were significantly improved (all p<.01). TMR, IG, SG, NIBUT, OSED (both corneal and conjunctival), CFG, and LG were also significantly improved (all p<.02).
Conclusions:
The findings of this study show that in patients suffering from aqueous tear deficient dry eye, punctal occlusion can improve almost all subjective symptoms and objective findings related to tear film instability and increased friction. It is therefore theorized that aqueous tear deficiency worsens dry eye due to the enhancement of both the tear film instability- and increased friction-related mechanisms.