PURPOSE. The purpose of this study is to compare the fitting characteristics of the 14.0-millimeter diameter Acuvue lenses in the 8.4mm and 8.8mm base curves to the fitting characteristics of the Acuvue 2 lenses with same overall diameter in the 8.3mm and 8.7mm base curve respectively. METHOD. Ten successful Acuvue lens wearers participated in this double-masked study. Each subject presented having worn his or her current Acuvue lenses for at least four hours. Centration of each lens was determined in primary gaze following a blink. Lens coverage was measured in relation to the patient’s limbus. Lens movement was assessed after a blink in primary gaze. Lens movement was also assessed by the digital push-up technique. Lens sag was measured from the inferior limbus with the patient looking in upward gaze. A single observer estimated all measurements. Next, each subject was randomly fit with a pair of Acuvue and a pair of Acuvue 2 lenses. Each lens matched the patient's current contact lens prescription. The same measurements were recorded with the newly fitted lenses.
RESULTS. No statistically significant differences were found between the presenting Acuvue lens, the fitted Acuvue lens, and the fitted Acuvue 2 lens with regards to temporal lens movement upon blinking (0.43mm, 0.37mm, and 0.37 mm respectively), lens sag on upward gaze (0.43mm, 0.46, and 0.56mm respectively), and lens movement with the push-up technique (1.25mm, 1.08mm, and 1.2 mm respectively). All lenses showed good centration with complete corneal coverage.
CONCLUSIONS. The results indicate that Acuvue and Acuvue 2 lenses do not have significant differences in fitting characteristics. This data suggests that eye care practitioners should be able to switch patients from Acuvue to Acuvue 2 lenses without a diagnostic fitting session. This could save the practitioner time and the patient money by eliminating the need for a diagnostic fit if a patient and/or the eye care practitioner wishes to switch from Acuvue to Acuvue 2 lenses.