Abstract
Purpose: :
quantify tear concentration of hyaluronic acid in normal subjects and patients with Graves Ophthalmopathy.
Methods: :
Tear samples were obtained from 15 normal subjects (30 eyes) without ocular or systemic diseases and from 43 patients (86 eyes) with Graves ophthalmopathy (GO). To collect the tear, Schirmer strips were placed in the temporal side of each eye under the eyelid, during 5 minutes, without any use of topical anesthetics, and total volume were quantified at strip scale (in millimeters). The strips were dried at room temperature and stored at –20o C until analysis. At the time of analysis, hyaluronic acid and total proteins were eluted from strips with distilled water and assayed with fluorometric and colorimetric technique, respectively.
Results: :
The mean of total of protein was 144.9 ± 78.1 µg (ranging from 37.5–342.6 µg). The mean of hyaluronic acid present in the tear was 18.9 ± 12.6 ng/mg protein (ranging from 3.2–45.0 ng/mg protein) in normal subjects and 35.1 ± 34.7 ng/mg protein in GO (p<0.01).
Conclusions: :
It is possible extract macromocules such as proteins and hyaluronic acid adsorbed on Schirmer's strips and measure their contents by conventional laboratories assays. In this pilot study, we observed statistically difference in hyaluronic acid contents between eyes with GO and normal subjects but it still need further studies. This new approach could be useful to investigative studies involving ocular and systemic diseases.
Keywords: cornea: tears/tear film/dry eye • autoimmune disease • orbit