Abstract
Purpose: :
To determine the long-term efficacy and biocompatibility of the PresbyLens® hydrogel corneal inlay for emmetropic presbyopes.
Methods: :
Eight emmetropic, presbyopic subjects (mean age 52 years [45 to 60], mean preop spherical equivalent +0.31 D [0.00 to +0.75 D], mean near add +2.03 D [+1.50 to +2.50 D]) were implanted with a 1.5 mm diameter PresbyLens under standard LASIK-flaps. The clinical tests were conducted under an IRB-approved protocol. At two year follow up, visual acuity was measured using an Optec 6500 Vision Tester and a slit lamp exam was performed to determine corneal clarity. In a porcine study, 12 Yucatan mini pigs were implanted with the PresbyLens in a microkeratome created pocket. Slit lamp exams were performed throughout the study and histology was performed on sacrificed pigs at 6 months and 1 year.
Results: :
In the human study, all eyes implanted retained 20/32 or better UCNVA at two years post-operatively, though no eyes achieved 20/40 or better UCNVA preoperatively. The mean gain in UCNVA was 3.6 lines [1.6 to 5 lines]. The mesopic UCDVA was minimally affected with a maximum of 3 lines lost in the implanted eye. On average, UCDVA in photopic conditions was 1.2 lines better than in mesopic conditions. Binocular mesopic UCDVA was 20/25 or better for all patients. All subjects report that they are satisfied with the surgery and are able to perform typical near tasks without glasses. The slit lamp examination revealed clear corneas with very mild edge haze. In the porcine study, the implanted eyes remain clear without any reaction to the corneal inlay for the entire duration of study. Slit lamp examination at one year revealed clear corneas and histology data suggest that the PresbyLens® inlay appears to be inert.
Conclusions: :
Both the two year results in 8 human eyes and one year follow-up in 6 porcine corneas support the long term safety and biocompatibility of the PresbyLens® corneal inlay for improvement of near and intermediate vision in presbyopes.
Keywords: presbyopia • refractive surgery: LASIK • refractive surgery