The United States continues to lead the world in innovative medical technology. However, the FDA’s stringent bureaucratic process makes it difficult for physicians in this country to gain access to novel treatments in a timely manner.
Despite recent attempts to streamline the cumbersome regulatory hurdles, it still takes many years and large amounts of money to obtain 510(k) clearance of a medical device, not to mention the obscene amount of time and money—in some cases more than a decade and more than a billion dollars—for approval of a new pharmaceutical agent. Consequently, many of the latest cutting edge technologies developed by U.S. companies are only commercially available outside the U.S. market.
Here are some of the most exciting anterior segment ophthalmic products that are not yet in the hands of US doctors:
Collagen Cross-Linking (CXL)
This procedure has been the standard of care in more than 60 countries for years. The use of riboflavin and UV light to strengthen corneas with ectasia is safe and effective. Although multicenter U.S. trial results are excellent and patient satisfaction is high, we are still awaiting FDA approval of the VibeX/KXL System from Avedro and the VEGA UV-A light system from Topcon.
Laser Vision Correction
Topography-guided laser systems for PRK were initially cleared by the FDA in 2013 but are still not used because of delays and limited approval. Novel refractive procedures such as ReLEx SMILE (Refractive LEnticule Extraction SMall Incision Lenticule Extraction), the minimally invasive, flapless treatment performed with the VisuMax femtosecond laser from ZEISS, also is not performed in this country.
Intracorneal Inlays
One of the most promising treatments for the surgical correction of presbyopia is corneal implants that are placed under a flap or into a pocket in the non-dominant eye. After years of study, one such device, Kamra from AcuFocus received FDA approval this year, but there are two other inlays that have not yet been cleared:
- Raindrop Near Vision Inlay from ReVision Optics: A hydrogel inlay with hyperprolate shape and no refractive power that steepens central cornea creating a multifocal cornea (2 mm diameter, 32 micron thickness).
- Flexivue Microlens from Presbia: A hydrophilic acrylic implant that increases corneal refractive power to produce slight myopia and monovision (3 mm implant, central plano zone with a ring of peripheral power (+1.25 to +3.5 D), 15 microns thick, 0.15 mm central opening for nutrient flow).
Phakic Intraocular Lenses
Newer generations of the Visian ICL from Staar Surgical, which are safer and can correct astigmatism, are not available in the U.S. The Visian ICL with CentraFLOW model eliminates the need for an iridotomy and has been implanted for years in other countries. The toric ICL for astigmatism is still awaiting final approval even though the FDA panel recommended approval in March 2014. Anterior chamber phakic lenses such as the Acrysof Cachet from Alcon and the Veriflex lens from AMO may never enter the U.S. market.
Advanced technology IOLs
Ophthalmologists in the U.S. do not have access to a plethora of novel IOL designs that could benefit patients. These include:
- Light Adjustable Lens from CalhounVision: This silicone lens features optics that can be adjusted postoperatively to correct for myopia, hyperopia, and astigmatism.
- Trifocal IOLs
- FineVision trifocal IOLs from PhysIOL: These hydrophobic acrylic diffractive 4 loop haptic IOLs also are available in a toric model. It is an aspheric, diffractive, apodized design with a 3.5 D near add and a 1.75 D intermediate add.
- AT LISA tri from ZEISS: This hydrophobic acrylic diffractive plate haptic lens 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
Outside of the U.S. there are toric versions of the popular ReSTOR from Alcon and Tecnis multifocal IOL from AMO. 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 percent 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.
IOL delivery systems
U.S. cataract surgeons have eagerly awaited preloaded IOLs, such as the Tecnis iTec from AMO, AcrySert C from Alcon, and iSert from Hoya. Other systems from PhysIOL and ZEISS also are in use in other countries. I am happy to report that the Tecnis preloaded IOL (PCB00) is now available in the U.S. This disposable screw-style injector system delivers a full range of monofocal IOLs (+5.0-+34.0 D) through a 2.2-2.4 mm incision.
Minimally Invasive Glaucoma Surgery
There are a number of exciting MIGS technologies available to U.S. surgeons including the EX-PRESS minishunt from Alcon, canaloplasty from iScience Interventional, Trabectome from NeoMedix, and iStent from Glaukos. Hopefully, others currently available outside the U.S. will gain FDA approval in the near future. These technologies include:
- CyPass from Transcend Medical: This polyamide stent can be inserted in the supraciliary space to increase uveoscleral outflow.
- Hydrus Microstent from Ivantis: This stent is placed ab interno to act as an intracanalicular scaffold to dilate Schlemm’s canal.
- XEN Gel Stent from AqueSys: A cylindrical cross-linked gelatin implant, this stent is placed ab interno into the subconjunctival space to create a tissue conforming drainage channel.
- DeepLight Gold micro-shunt from SOLX: This supraciliary device can be implanted ab externo to increase uveoscleral outflow.
Artificial Iris
For more than a decade, partial or complete aniridia is treated outside the U.S. with Iris Diaphragm implants from Morcher. Another iris prosthesis, the CustomFlex artificial iris from HumanOptics is a silicone device used to repair iris defects. This artificial iris is customized to match the appearance of the patient’s fellow eye, but it can only be obtained in the U.S. under a compassionate use exemption.
Retinal Imaging
Fundus imaging technology is continually improving and there are some advanced instruments that are not yet sold in the U.S.:
- IDx-DR Smart Retinal Imaging System from IDx: This automated retinal imaging system captures high quality fundus photos with a digital camera and then analyzes the pictures for pathology such as diabetic retinopathy, hypertensive retinopathy, glaucoma and infections. The device was developed in the U.S. and is intended to be used in primary care offices as a diagnostic screening test.
- AngioVue from Optovue: This is the first commercially available optical coherence tomography angiography (OCTA) system. It was also developed in the U.S. but is not yet approved for sale in this country. This SD-OCT device has Motion Correction Technology and Split Spectrum Amplitude Decorrelation Angiography to enable enface 3D visualization of the superficial and deep capillary plexus, outer retina, and choriocapillaris.
This is just a small sample of the innovative ophthalmic technology and products, many of which were developed in the U.S., that are only available outside the country. The delay in FDA approval affects every medical specialty, so our frustration as ophthalmologists is shared by all physicians in this country.
Hopefully, our government’s attempts to improve the regulatory process will help bring these and other valuable products to market sooner. I look forward to writing a future update on this topic when I will be able to report that most of the new products in use worldwide are also available to U.S. physicians and patients.