To evaluate accommodative response and facility in presbyopic patients fitted with several types of simultaneous-image
multifocal contact lenses (CLs).
Six presbyopic patients, unadapted wearers of simultaneous-image
bifocals, were fitted with the Focus Progressives and the low- and high-addition Pure Vision simultaneous vision multifocal CLs. Each individual wore each of the three types of lenses in successive random order. Accommodative response, accommodative facility, visual acuity, and contrast sensitivity at distance and near were evaluated in all cases. A control group of eight non-presbyopic patients was also studied.
The mean age was 28.6 ± 2.72 and 51.2 ± 5.81 years in the non-presbyopes and presbyopic patients, respectively. For the presbyopic group, statistically significant differences were not found for distance visual acuity between the baseline situations and with the three different CLs types. For the near visual acuity, there were no statistically significant differences between baseline situation (without add) compared with patients wearing the Focus Progressives and with PureVision Low Add. With the Purevision High Add, the near visual acuity was slightly better than baseline situation (p = 0.03). Non-presbyopic subjects showed relatively linear 1:1 stimulus response functions for all situations. Presbyopic subjects showed an increasing lag of accommodation
with amplitude as they approach to the maximum amplitude for all situations. Distance and near accommodative facility rate for the presbyopic patients was zero for all conditions.
The results of this study suggest that simultaneous-image
multifocal CLs studied do not alter accommodative functions. The high add of the Purevision CL enhances near vision for advanced presbyopes compared with the other models studied.