While the United States is at the forefront of medical innovation, it remains an unfortunate reality that many of the technologies developed in this country are not available to U.S. physicians and their patients. Due to regulatory requirements and other factors, when new products are released in the U.S. market it is often many years after they have been introduced to the rest of the world.
Just because there products are not yet available in the U.S. doesn’t mean they are not important. In this article I review some of the most interesting ophthalmic products available overseas and eagerly awaited by U.S. ophthalmologists.
Collagen Cross-Linking (CXL)
This procedure combining riboflavin and UV light to strengthen corneas with ectasia is the standard treatment outside the United States. It has also demonstrated efficacy in treating infectious keratitis. The FDA trials continue to show excellent results and high patient satisfaction, but the VibeX/KXL System from Avedro and VEGA UV-A light system from Topcon have not yet been approved.
Phakic Intraocular Lenses
Improved posterior chamber lens designs such as the toric ICL and V4c CentraFLOW ICL from Staar Surgical which eliminates the need for an iridotomy are routinely implanted outside the U.S. The Cachet from Alcon and the Veriflex lens from AMO are anterior chamber phakic implants that also are unavailable in the U.S.
These corneal implants to correct presbyopia are placed in the cornea under a flap or into a pocket in the patient’s nondominant eye. Clinical results have demonstrated their safety and efficacy, but the inlays are still awaiting FDA approval.
Kamra from AcuFocus: A Polyvinylidene small aperture optic that utilizes the pinhole principle to increase depth of field. The optic is a 3.8 mm opaque disc with a 1.6 mm central opening and 5 microns thick. There are 8,400 micro-perforations to allow nutrient flow.
Raindrop Near Vision Inlay from ReVision Optics: A hydrogel inlay with hyperprolate shape and no refractive power that steepens the central cornea creating a multifocal cornea. The inlay size is 2 mm diameter with a 32 micron thickness.
Flexivue Microlens from Presbia: This hydrophilic acrylic implant increases corneal refractive power to produce slight myopia and monovision. This is a 3 mm implant with a central plano zone with a ring of peripheral power (+1.25 to +3.5 D) and it is 15 microns thick with a 0.15 mm central opening for nutrient flow.
IOL Delivery Systems
Preloaded IOLs such as the Tecnis iTec from AMO, AcrySert C from Alcon, and iSert from Hoya are not available in the United States. A number of other preloaded IOL systems made by PhysIOL and Carl Zeiss Meditec also are routinely used outside this country. Automated injector systems such as the Intrepid AutoSert injector from Alcon and the Bausch + Lomb Injector System (BLIS) are in use in the U.S., so hopefully preloaded systems will be available in the near future.
Advanced Technology IOLs
Light Adjustable Lens from Calhoun Vision: A silicone lens with optics that can be adjusted postoperatively.
FineVision trifocal from PhysIOL: A hydrophobic acrylic diffractive 4 loop haptic IOL that is also available in a toric model, it features an aspheric, diffractive, apodized design with a 3.5 D near add, and a 1.75 D intermediate add.
AT LISA tri from Carl Zeiss Meditec: A hydrophobic acrylic diffractive plate haptic lens that also has a toric version. The intermediate add is 1.66 D and the near add is 3.33D. The trifocal portion is contained in the central 4.34 mm and the bifocal portion resides in the area peripheral to this. The IOL is independent of pupil size for near vision.
Both IOLs can be injected through a 1.8 mm incision with a preloaded injector system.
Multifocal Toric IOLs
There are toric versions of the popular ReSTOR from Alcon and Tecnis multifocal from AMO IOLs available outside the U.S. Other toric multifocal IOLs in use in other countries include:
Tecnis Symfony ZXR00 from AMO: This achromatic, aspheric, one-piece acrylic lens with traditional haptics corrects aberrations and improves image quality and contrast. It has 50% less light loss than other diffractive IOL designs, enhanced depth of focus, sharp image quality, and minimal dysphotopsias. The lens design has an anterior aspheric surface and a posterior achromatic diffractive surface. The power range is +5.0 D to +34.0 D, and the toric version corrects for 1.00, 1.50, 2.25, 3.00, and 3.75 D of cylinder at the IOL plane.
M-flex T Multifocal Toric from Rayner: This one-piece acrylic multi-zone refractive aspheric lens is available in two sizes and each has a 3 and 4 D add version. The cylinder correction ranges from 1.00 to 6.00 D in 0.5 D steps.
Mplus and Mplus toric from Oculentis: This is a refractive multifocal one-piece plate haptic acrylic lens. The IOL has an asymmetric design with a distance zone and a sector-shaped near segment having a 3.0 D add on the anterior surface, while the aspheric and toric optics are on the posterior surface. The lens is pupil independent, and the unique design reduces glare and halo. There is also a low add version with 1.50 D for better intermediate vision.
Laser Vision Correction
Topography-guided PRK treatments have been FDA approved but are still not available in the U.S. due to delays. Novel refractive procedures such as ReLEx (Refractive Lenticule Extraction) SMILE (Small Incision Lenticule Extraction), a minimally invasive, flapless, treatment performed with the VisuMax femtosecond laser from Carl Zeiss Meditec is also only available outside the U.S.
Minimally Invasive Glaucoma Surgery
Although several MIGS technologies such as Alcon’s Ex-PRESS minishunt, canaloplasty from iScience Interventional, Trabectome from NeoMedicx, and iStent from Glaukos are available in the U.S., there are others that are only available outside this country.
CyPass from Transcend Medical: A polyamide stent inserted in the supraciliary space to increase uveoscleral outflow.
Hydrus Microstent from Ivantis: A stent placed ab interno that acts as an intracanalicular scaffold to dilate Schlemm’s canal.
XEN Gel Stent from AqueSys: A cylindrical cross-linked gelatin implant placed ab interno into the subconjunctival space to create a tissue conforming drainage channel.
DeepLight Gold micro-shunt from SOLX: A supraciliary device implanted ab externo to increase uveoscleral outflow.
Iris Diaphragm implants from Morcher have been used outside the U.S. for more than a decade to treat partial or complete aniridia. The CustomFlex artificial iris from HumanOptics is a silicone prosthesis used for the repair of iris defects. This custom made prosthesis is made to match the appearance of the patient’s fellow eye and is available in the U.S. but only under compassionate use exemptions.