Purpose:
To determine whether the flap-making device (mechanical keratome versus femtosecond laser) affects visual acuity outcomes with implantation of the PrebyLens® hydrogel corneal inlay in emmetropic presbyopes.
Methods:
LASIK-style flaps were cut for 39 presbyopic emmetropes using a mechanical keratome (Hansatome®, MK) and 20 subjects using a femtosecond laser keratome (IntraLase®, IL). The mean ages (50, 49), mean preop SE (0.20 D, 0.07 D), and mean add requirement (1.8 D, 1.7 D) were similar for both groups. All subjects received a 2.0 mm diameter PresbyLenses. The study was under an IRB-approved protocol. The Optec® 6500 Vision Tester was used to record mesopic UCDVA, photopic UCIVA, and photopic UCNVA. OCT images were analyzed for flap bed curvatures.
Results:
The only statistically significant (p < 0.05) finding was that post-op UCNVA was better for the IL group though UCDVA was better and more improved at a statistically less significant level (p < 0.1) for the MK group. Analysis of OCT (Optovue®) images showed no difference in mean flap bed radii of curvatures (MK = 7.8 ± 0.27 mm, IL = 7.9 ± 0.17 mm). Differences in the standard deviation of the post-op UCNVA were also observed; MK at 0.15 ± 0.15 logMAR and IL at 0.04 ± 0.09 logMAR.
Conclusions:
Both flap making methods provide significant improvement in UCNVA and UCIVA with the PrebyLens® intracorneal inlay. Better and more improved UCNVA was observed for the IL flaps, possibly due to their greater consistency of flap bed geometry.
Keywords: cornea: clinical science • presbyopia • refractive surgery