Effect of Particulate Matter on the Tear Film in Contact Lens Wearers

Abstract

Purpose : To investigate the influence of particulate matter (PM) on tear film in contact lens (CL) wearers, the tear volume and stability were evaluated according to the level of PM. Methods : Thirty-one myopes in their 20s wearing glasses and CL were participated, and they were required to wear soft CL (L brand, 55% water content) for 8 hours a day. The subjects were divided into the normal and dry eye groups according to the OSDI score. The levels of PM were divided good (0~30 ㎍/m³) and bad (51~100 ㎍/m³) according to the criteria provided by the Korea Environment Corporation. The tear tests were conducted both on the good and bad PM days. Tear volume was evaluated by OCCUTUBE and the stability was evaluated by TBUT and NIBUT. The results were analyzed using SPSS according to the level of PM. Results : On the day of bad PM level, the tear volume and stability were significantly decreased both wearing glasses and CL (p＜0.050) on to the level of dry eye. With the CL wearing tear volume was decreased even on the day of good PM level and TBUT was decreased on the day of bad PM level compared with glasses wearing. In dry eye group, TBUT was decreased significantly with CL wearing compared with normal group on the day of bad PM level. Conclusion : PM reduces both the amount and stability of tear that it could be the one of causes of dry eye, and wearing CL at the bad PM level deteriorated the tear film stability that the symptoms of dry eye patients may be worsened, so it is thought that wearing glasses should be recommended for contact lens wearers on the day of bad PM to prevent the dry eye.