Dr. Guy Kleinman
Professor David Apple
The 2006 ASCRS meeting got off to a great start for Rayner with an important report from Prof. David Apple and Dr Guy Kleinman (Salt Lake City Utah, USA) on work carried out earlier this year on Rayner’s new small incision lens injector.
The R-INJ-O4 Soft Tipped Injector is a new round-nozzled lens injector manufactured by Rayner Intraocular lenses Ltd., Hove East Sussex, England. Dr Kleinmann explained that the rounded nozzle was much gentler on the lenses than other designs of injector nozzles. He referred to a previous study where Prof Apple’s group found deposits on the posterior optical surface of lenses manufactured by other companies after implantation through a hexagonal cartridge. “These deposits were not found when the same IOL was implanted through a round/oval cartridge. Also, we found no deposits with the Rayner round nozzle injector.”
In the present study, Rayner C-flex® IOLs from +10D to +30D were tested in the R-INJ-04 Soft tipped injector using Healon, (AMO, Santa Ana, CA, USA) applied to the barrel and both sides of the inner portion of the loading area of the injector. Dr Kleinmann said that “the amount of Healon that we used for each implantation/injection was evaluated subjectively and was documented.
The IOLs were loaded according to the company’s instructions for use. After 3 minutes in the injector, using gentle pressure on plunger the IOLs were injected, into a Petri dish.”
“We made a gross (macroscopic) analysis of each IOL and the injector and then evaluated both of them microscopically and photographed them under a light microscope. One lens of each power and the injector that was used for the implantation were then sent to the Electron Microscopy Center of the University of South Carolina, (Columbia, SC) for further examination under a scanning electron microscope (SEM). The rest of the IOLs were stored in sealed vials with BSS and were sent to Rayner for power and MTF measurement.”
“All the implantations/injections were successful. No damage to the IOLs and to the injectors was found by gross examination, light microscopy, and SEM. No deposits were found on the IOL optical surfaces or haptics. Normal remnants of OVD/BSS materials that were found on the IOL surfaces were easily removed with short rinsing of the IOLs.”
Mike Ring, Rayner’s Director of Operations added,“the lenses returned by Dr Kleinmann were all re-examined for power and MTF. The results show a very close match for the original measurements made at the time of manufacture. This shows the lens power and light transmission properties are not damaged by the process of injection.”
Prof Apple concludes, “In this study we demonstrated that the Rayner (R-INJ-04 Soft Tipped) Injector is safe for the implantation of the C-flex® intraocular lens with power ranged from +10.0 D to +30.0 D. No structural damage to the IOLs and to the injectors was found.”
The authors summarised this study with the results from previous work: “We previously demonstrated that while using a hexagonal cartridge for the implantation of a different hydrophilic acrylic IOL, deposits were found on the IOL’s posterior optical surface and the injector was found to have a major break line with several stress lines. Implantation of the same IOL through a round cartridge showed no damage or deposits. The origin of the deposits on the IOL surface concluded to be the injector inner part. The mismatch between the hexagonal cartridge and the oval/round profile of the folded IOL increased the stress forces applied to the cartridge and thus cause extensive friction of the IOL’s posterior surface (external surface of the IOL when folded) against the inner part of the cartridge. This could result in a shaving or exfoliation with deposit formations onto the posterior surface of the IOL derived from the inner part of the cartridge surface.”
“The plunger tip of the R-INJ-04 soft tipped injector is manufactured from a soft material, this allows the plunger to compress during the progression through the narrowing nozzle and by doing that it fills the nozzle completely and tightly. In that way, if loaded correctly, no part of the lens can be trapped between the plunger and the nozzle, also override of the plunger over the IOL is impossible.”
“The results show the superiority of using a round nozzle over a hexagonal one. The Rayner injector left the lenses undamaged.”
Since the beginning of 2006 all Rayner C-flex® family lenses are packaged with the new R-INJ-O4 Soft Tipped Injector.
The authors may be contacted at:
Prof. David J Apple MD & Dr. Guy Kleinmann MD.
The David J Apple, MD, Laboratories for Ophthalmic Devices Research,
John A. Moran Eye Center,
Department of Ophthalmology and Visual Sciences,
University of Utah,
Salt Lake City,
Utah, USA.
Email:
Guy Kleinmann guy.kleinmann@hsc.utah.edu
David Apple djapple@comcast.net
