Purchase this article with an account.
Louis Tong, Roger Beuerman, Susan Simonyi, David A Hollander, Michael E Stern; Effects of punctal occlusion on tear cytokine levels and relationship to baseline clinical characteristics. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):4435.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Punctal occlusion, which reduces tear turnover, is a common treatment option for dry eye. There is limited evidence that occlusion alters tear protein composition. This longitudinal study evaluated signs and symptoms, and tear cytokine levels after punctal occlusion and assessed factors associated with cytokine changes in dry eye patients.
Non-adsorbable, parasol type silicone plugs were inserted bilaterally in the lower punctum of patients (n=29) with moderate dry eye and persistent symptoms (2 or more symptoms ≥ grade 3). Clinical signs and global symptom score were assessed and tears were tested for 15 cytokines and matrix metalloproteinase-9 (MMP-9) by indirect immunofluorescence, at baseline up to 3 weeks after punctal occlusion. Multivariate analysis used repeat measure general linear modeling with dependent variables of cytokine and MMP-9 levels and effects of age, gender, baseline dry eye characteristics (Schirmer’s score, tear break-up time, global irritation), and time (baseline, week 1, week 3) to identify factors associated with cytokine levels.
Punctal occlusion reduced fluorescein staining in all zones (P<.01) except inferior zone and decreased global irritation score (P<.001) after 3 weeks. Patients with low Schirmer’s scores (≤8 mm) at baseline had higher levels of several cytokines, including TNF-α (P<.001), IL-2 (P<.03) and MIP-1α (P<.002). For most cytokines and MMP-9, there was no relationship between levels and time, and cytokine levels elevated at baseline remained high post-occlusion. Time was a significant factor only in a model of IFN-γ, IL-10, IL-12 and TNF-α, with cytokine levels adjusted by baseline Schirmer’s and global irritation scores; increases in all four cytokines after punctal occlusion occurred in patients with Schirmer’s score ≤8 mm and high irritation scores (>55.3) at baseline. The interaction of time and irritation scores was also significant in the model.
Overall cytokine and metalloproteinase concentrations were not significantly affected following punctal occlusion. Cytokine modeling identified some baseline characteristics as potential factors associated with cytokine levels. The lack of a significant effect of punctal plugs on tear cytokines suggests that dry eye patients would benefit from earlier treatment with anti-inflammatory agents for management of their disease.
This PDF is available to Subscribers Only