Lid Margin And Conjunctival Microbial Flora Following Punctum Occlusion

This study will investigate the impact of punctal occlusion on the ocular microbial flora. Current thought is that punctal occlusion causes retention of inflammatory mediators on the ocular surface which may produce pathology, we hypothesize that blockage of the nasolacrimal drainage system may allow colonization of the ocular surface by potentially pathogenic ubiquitous organisms (which may produce exotoxins and other biologic products) that may be responsible for signs and symptoms seen in some patients. Additionally, the presence of the silicone foreign body(punctal plug) may act as a nidus for bacterial adhesion with biofilm production (which is known to occur with Pseudomonas sp and other organisms). There would thus be a paradigm shift of our current understanding of the pathophysiology of punctal occlusion. Additionally, the choice of antimicrobials for the treatment of infections in patients with punctal occlusion may need to be modified if the microbial flora is found to be different in patients with punctal occlusion.

The ocular flora may be different inpatients with severe dry eye or other chronic pathologic conditions, which are frequent indications for punctal occlusion. However, from our retrospective review, we could not determine if there was a change in the microbial flora following plug placement with colonization with these "unusual organisms" since baseline cultures prior to punctal plug placement were not obtained.

We will try to differentiate any effect on the microbial flora caused by the silicone plug or acrylic plug(as a foreign body) versus the punctal closure by thermocautery. (Punctal thermocauterization is an alternative method of punctal closure which is 1) the preferred choice by some ophthalmologists for all their cases, or 2) when the dry eye is severe and irreversible punctal occlusion is desired or 3) if punctal plugs can not be retained due to the large size of the patients punctal). The thermodynamic hydrophobic acrylic plug(SmartPLUG) approved by the FDA for punctal occlusion with the same indications as the traditional silicone plug.