Purchase this article with an account.
Bartlomiej Jan Kaluzny, Patryk Mlyniuk, Joanna Stachura, Alfonso Jimenez-Villar, Ireneusz Grulkowski; Reciprocal geometrical interactions of modern soft contact lenses and the corneal epithelium. Invest. Ophthalmol. Vis. Sci. 2019;60(9):6355. doi: https://doi.org/.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
There is little scientific data on reciprocal geometrical interactions of modern soft contact lenses and the corneal epithelium. The aim of this study is to evaluate the changes of the anterior surface of the cornea and soft silicone hydrogel contact lens’ shape during wear.
Forty three eyes of 23 patients with myopia of -3,0 D were enrolled. All patients underwent general ophthalmic examination, corneal topography/tomography (Placido/Scheimpflug instrument), total corneal thickness and epithelial thickness mapping (optical coherence tomography, OCT) and specular microscopy. Subsequently, all patients wore soft silicone hydrogel contact lenses with moderate Young’s modulus continuously for 7 days. After that, the eyes were examined again. Contact lenses geometry was measured immediately after removal in two perpendicular planes in a wet cell with the use of a custom built swept source OCT prototype operating at the central wavelength of 1310 nm and at the speed of 50 000 scans per second. The results were compared with the ones achieved with the new contact lenses of the same design and power of -3.0 D (Fig. 1).
We did not observed statistically significant difference in central, minimal and maximal epithelial thickness nor in the mean keratometry value after the contact lens wear. There was a decrease of mean endothelial cell density by 57.81±144.33/mm3 (p=0.012). We found a significant decrease in contact lenses anterior central curvature by 0.77±0.25 and 0.62±0.23 mm in two perpendicular planes (p<0.001) and posterior central curvature by 0.65±0.24 and 0.49±0.21 respectively (p<0.001). The change in contact lens curvature correlated with the mean keratometry value of the cornea for both anterior and posterior surface of the lens (r=0.44, p<0.001 and r=0.46, p<0.001).
Continuous wear of soft silicone hydrogel contact lens for low myopia does not change keratometry readings nor epithelial thickness profile. The curvatures of the contact lens, however, decrease during the wear to imitate geometry of the anterior surface of the cornea.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
This PDF is available to Subscribers Only