Safety and effectiveness of a glistening-free single-piece hydrophobic acrylic intraocular lens (enVista)

Abstract

PurposeTo evaluate the safety and effectiveness of a single-piece hydrophobic acrylic intraocular lens (IOL; enVista model MX60; Bausch & Lomb, Rochester, NY, USA) when used to correct aphakia following cataract extraction in adults.MethodsThis was a prospective case series (NCT01230060) conducted in private practices in the US. Eligible subjects were adult patients with age-related cataract amenable to treatment with standard phacoemulsification/extracapsular cataract extraction. With follow-up of 6 months, primary safety and effectiveness end points included the rates of US Food and Drug Administration (FDA)-defined cumulative and persistent adverse events and the percentage of subjects who achieved best-corrected visual acuity (BCVA) of 20/40 or better at final visit. To evaluate rotational stability, subjects were randomized (1:1:1:1) to have the lens implanted in one of four axis positions in 45° increments.ResultsA total of 122 subjects were enrolled. The rate of cumulative and persistent adverse events did not significantly exceed historical controls, as per FDA draft guidance. At the final postoperative visit, all subjects (100%) achieved a BCVA of 20/40 compared with the FDA historical control of 96.7%. Rotation of the IOL between the two final follow-up visits was ≤5° for 100% of eyes, and refractive stability was demonstrated. A low evaluation of posterior capsule opacification score was demonstrated, and no glistenings of any grade were reported for any subject at any visit.ConclusionThis study demonstrated the safety and effectiveness of the MX60 IOL. Favorable clinical outcomes included preserved BCVA, excellent rotational and refractive stability, no glistenings, and a low evaluation of posterior capsule opacification score.

Transscleral fixation of single-piece foldable acrylic lens with eyelets at the optic-haptic junction

“…39 It is interesting to note that the enVista is the only foldable IOL that has eyelets, contrary to prior IOLs that were made of polymethylmethacrylate, such as the CZ70BD (Alcon Laboratories Inc, Fort Worth, Tex.). 21,38 The small corneal incision used in our study also yielded stable postoperative refractory error results. In addition, the small incision provides the advantage of operating in a relatively closed system that can prevent intraoperative complications such as transient hypotony and can help surgeons to operate comfortably during fixation with improved globe stability.…”

“…The enVista IOL is composed of both an optic and haptics with a hydrophobic acrylic polymer. 21 Its optic is biconvex with a body diameter of 6.0 mm and an overall length of 12.5 mm. It has modified C-loop haptics and eyelets at the optic-haptic junctions (Fig.…”

“…1). 21 Clinical characteristics of the subjects, including age, sex, medical history, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refractive errors, intraocular pressure (IOP) measurement using Goldmann applanation tonometry, together with slit-lamp microscopic examination of anterior segment and fundus examination, were evaluated preoperatively and at the postoperative follow-up. The BCVA was determined by best spectacle-corrected distance visual acuity in Snellen visual acuity charts.…”

New Hydrophobic IOL Materials and Understanding the Science of Glistenings

“…84 In this study, a very sharp tip was brought onto the surface of the IOL, and the displacement of the tip into the surface was recorded as a function of force applied. 81 It was found that the AcrySof, Hoya, and Sensar materials indented by 800-1000 nm with an applied force of 60 mN, while the PHS copolymer only indented by 150 nm. From these measurements, and the dimensions of the tip, the surface hardness can be calculated.…”

“…Here, we will focus on one modern IOL polymer that is made of materials combining the best aspects of earlier hydrophobic and hydrophilic polymers, used in the Bausch & Lomb enVista (previously the AVS EXACT) and the Eternity IOL in Japan. This particular material, found to be glistening-free when packaged in 0.9% saline solution, 80,81 is currently the only hydrophobic IOL material with a published composition that contains a substantial hydrophilic component. Figure 9 shows the components of this hydrophobic/hydrophilic hybrid material, which is actually a copolymer of three different monomers PEG-PEA/HEMA/styrene (collectively called the PHS copolymer) and a crosslinker.…”