Abstract
Purpose:
To evaluate the utility of an auto-refractor for multifocal contact lenses over-refraction
Methods:
Non-cyclopegic distance refractive error was measured in patients wearing multifocal contact lenses by means of the Grand Seiko Auto Ref/Keratometer WAM-5500 auto-refractometer and compared with subjective measurements. Three commercial multifocal contact lenses were evaluated: Air Optix Multifocal, Ciba Vision (refractive bi-aspheric lens with near vision in the centre), Proclear Multifocal, CooperVision (refractive lens with aspheric centre with near vision in it), Acuvue Oasys Multifocal, Johnson & Johnson (refractive lens with a multicurve design). 30 eyes of 15 healthy adults were measured in the study, with a mean ± SD in age of 27.67 ± 1.86 years (range: 25 to 30 years), subjective spherical refraction of -2.43 ± 3.56 D (+2.50 to -9.50 D), subjective astigmatic refraction of -0.48 ± 0.44 D (0 to -1.25 D), best corrected visual acuity in the logMAR scale of -0.21 ± 0.07 (-0.1 to -0.34). The results of over-refraction were evaluated in terms of M, J0 and J45.
Results:
The mean difference between auto-refractometer and subjective spherical over-refraction was 0.52 ± 0.37D (range: +1.08 to +0.02D) for the Air Optix lens, 0.62 ± 0.43D (range: +0.94 to +0.32D) for the Proclear lens and -0.15 ± 0.11D (range: +0.07 to -0.46D) for the Acuvue Oasys lens. The mean differences in astigmatic over-refraction in terms of J0 and J45 were -0.04 ± 0.03D (range: +0.32 to -0.55) and -0.05 ± 0.04D (range: +0.15 to -0.31D) for the Air Optix lens, 0.17 ± 0.07D (range: +0.22 to +0.12D) and 0.05 ± 0.04D (range: +0.42 to -0.33D) for the Proclear lens and -0.23 ± 0.17D (range: +0.03 to -0.50D) and -0.05 ± 0.03D (range: +0.17 to -0.29D) for the Acuvue Oasys lens.
Conclusions:
We have measured the over-refraction in multifocal contact lenses users with an auto-refractometer and compared with subjective over-refraction. The results from our measurements highlighted a good agreement between subjective and objective values in both spherical and cylindrical refractions, although some discrepancies were found on patients with high refractive errors. Thus, we can conclude that auto-refractor is an useful tool for over-refraction in patients wearing multifocal contact lenses although care must be taken in highly myopic or hyperopic users.
Keywords: 477 contact lens