Short-Term Deposition of PM2.5 Particles on Contact Lens Surfaces: Effect on Oxygen Permeability and Refractive Index

Zhizhang Dong; Xiaoyan Ding; Yong Li; Yifeng Gan; Yanhui Wang; Libin Xu; Yahong Wang; Ying Zhou; Juan Li

doi:10.1080/02713683.2018.1476552

Short-Term Deposition of PM_2.5 Particles on Contact Lens Surfaces: Effect on Oxygen Permeability and Refractive Index

Curr Eye Res. 2018 Sep;43(9):1102-1107. doi: 10.1080/02713683.2018.1476552. Epub 2018 Jun 5.

Authors

Zhizhang Dong¹, Xiaoyan Ding², Yong Li³, Yifeng Gan¹, Yanhui Wang⁴, Libin Xu⁴, Yahong Wang⁵, Ying Zhou⁶, Juan Li³

Affiliations

¹ b Department of Ophthalmology , The Seconnd affiliated hospital & Yuying Children's hospital of Wenzhou Medical University , Wenzhou , China.
² c Department of Ophthalmology , Xi'an No.3 Hospital, Xi'an , Shaanxi Province , China.
³ a Department of Ophthalmology , Shaanxi Ophthalmic Medical Center, Xi'an No.4 Hospital, Guangren Hospital Affiliated to School of Medicine of Xi'an Jiaotong University , Xi'an , China.
⁴ d Shaanxi Medical Device Testing , Xi'an , China.
⁵ e Environmental Monitoring Station of Xi'an , Xi'an , China.
⁶ f Department of Ophthalmology , The First Affiliated hospital of University of south China , Hengyang , China.

PMID: 29787322
DOI: 10.1080/02713683.2018.1476552

Abstract

Purposes: To identify the deposition of fine (≤2.5 μm diameter) particulate matter (PM) particles (PM_2.5) on contact lens surfaces and to investigate the effects of such deposition on the oxygen permeability (OP) and refractive index (RI) of contact lenses.

Methods: A total of 36 contact lenses, including rigid gas permeable (RGP) lens and soft contact lens (SCL), were investigated. RGP lens (n=12) and SCL (n=12) (experimental group) were incubated in a PM_2.5 solution for 24 h, after which PM_2.5-treated RGP lens (n=6) and SCL (n=6) were further washed for 1 h in phosphate-buffered saline (PBS). All lenses were examined by field emission scanning electron microscopy. OP and RI of all lenses were measured.

Results: Average-sized PM_2.5 particles deposited on RGP contact lens and SCL surfaces after immersion in the PM_2.5 solution were 3.192 ± 1.637 and 2.158 ± 1.187/100 μm², respectively. On RGP lens surfaces, we observed both large (≥2.5 µm diameter) and small (PM_2.5) particles. PM_2.5 particles were deposited in diffuse patterns, primarily along the honeycomb structural border of SCL, while no PM_2.5 particles were found in the honeycomb hole of SCL surfaces. Washing in PBS removed the larger PM particles from RGP lens surfaces, but left copious amounts of PM_2.5 particles. In contrast, nearly all PM particles were removed from SCL surfaces after PBS washing. OP values of RGP lens and SCL appeared to be unchanged by PM_2.5 deposition. RI values increased in both RGP lens and SCL groups after PM_2.5 deposition. However, these increases were not statistically significant, suggesting that PM_2.5 deposition itself does not cause fluctuations in contact lens RI.

Conclusions: Deposition of PM_2.5 particles on contact lens surfaces varies according to lens material. PM_2.5 particles deposited on SCL, but only large particles on RGP surfaces were able to be removed by washing in PBS and did not appear to alter OP and RI of either lens type.

Keywords: Contact lens; oxygen permeability; particulate matter; refractive index; scanning electron microscopy.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Contact Lenses, Hydrophilic*
Humans
Microscopy, Electron, Scanning
Oxygen / metabolism*
Particulate Matter / analysis*
Permeability
Refractometry

Substances

Particulate Matter
Oxygen