Purpose: To compare the performance of a low-addition silicone hydrogel multifocal soft lens with other soft lens correction options in a group of habitual soft lens wearers of distance correction who are symptomatic of early presbyopia.
Method: This clinical study was designed as a prospective, double-masked, randomized, crossover, dispensing trial consisting of four 1-week phases, one for each of the correction modalities: a low-addition silicone hydrogel multifocal soft lens, monovision, habitual correction, and optimized distance visual correction. The prescriptions of all modalities were finalized at a single fitting visit, and the lenses were worn according to a randomized schedule. All lenses were made from lotrafilcon B material. A series of objective vision tests were conducted: high- and low-contrast LogMAR under high- and low-room lighting conditions, stereopsis, and critical print size. A number of other data collection methods used were novel: some data were collected under controlled laboratory-based conditions and others under "real-world" conditions, some of which were completed on a BlackBerry hand-held communication device.
Results: All participants were able to be fit with all four correction modalities. Objective vision tests showed no statistical difference between the lens modalities except in the case of low-contrast near LogMAR acuity under low-lighting levels where monovision (+0.29 +/- 0.10) performed better than the multifocal (+0.33 +/- 0.11, P=0.027) and the habitual (+0.37 +/- 0.12, P<0.001) modalities. Subjective ratings indicated a statistically better performance provided by the multifocal correction compared with monovision, particularly for the vision associated with driving tasks such as driving during the daytime (93.3 +/- 8.8 vs. 84.2 +/- 23.7, P=0.05), at nighttime (88.8 +/- 11.7 vs. 74.9 +/- 23.6, P=0.001), any associated haloes or glare (92.0 +/- 10.6 vs. 78.0 +/- 22.8, P=0.003), and observing road signs (90.1 +/- 11.8 vs. 79.4 +/- 20.2, P=0.027). Preference for the multifocal compared with monovision was also reported when watching television (95.0 +/- 6.4 vs. 82.6 +/- 20.1, P=0.001) and when changing focus from distance to near (87.0 +/- 13.4 vs. 66.1 +/- 32.2, P<0.001).
Conclusions: For this group of early presbyopes, the AIR OPTIX AQUA MULTIFOCAL--Low Add provided a successful option for visual correction, which was supported by the results of subjective ratings, many of which were made during or immediately after performing such activities as reading, using a computer, watching television, and driving. These results suggest that making a prediction of "success or not" based on consulting room acuity tests alone is probably unwise.