Three-point-touch vs flat fittings of Rose K2 lenses in keratoconus: an assessment of the success rate

Abstract

Topic outline: Examining the manufacturers’ claims of High Definition (HD) in contact lens design. The claims of HD vision suggest spherical aberration correction is achieved by wearing contact lenses. The study involved wavefront aberration assessment whilst patients wear contact lenses of three of the leading contact lenses, (Senofilcon A) Oasys, PV2HD (Balafilcon A) and O2OPTIX Lotrafilcon B. These measurements were taken for a range of powers from +3.00 to −6.00, through dilated pupils using 0.5% tropicamide. This was conducted as a single blind cross over study. Results show a best fit regression analysis of each lens tested across the range of powers from −6.00DS to +3.00DS show a significance difference in management of spherical aberrations dependent on lens design and power. (Graphic evidence is compelling). Scotopic pupil sizes of 6.00mm show a significant difference in aberration correction. The average spherical aberration at 6.00mm diameter in the population is 0.12 microns. PureVision2HD corrects on average 0.12 microns of Spherical Aberration compared to only 0.07 micron and 0.05 micron for Acuvue Oasis and Air Optix respectively. The difference in aberration were statistically significant (p<0.05). The study supports the manufacturers claim that “Spherical Aberration Correction can be achieved by lens design” across the power range +3.00DS to −6.00DS. Under lighting conditions that represent night driving (pupil diameter of 6.00mm) contact lenses can benefit the majority of patients. Whilst this represents a vision upgrade, does it provide patients perception of “HD” vision?