List of soft contact lens materials

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FDA Classification of soft contact lenses

Soft contact lenses are one of several types on the U.S. Market approved by the U.S. Food and Drug Administration[1] for corrective vision eyewear as prescribed by optometrists and ophthamologists.[2] The American Optometric Association published a contact lens comparison chart called Advantages and Disadvantages of Various Types of Contact Lenses on the differences between them.[3] These include:

  • soft contact lenses
  • rigid gas-permeable (RGP)
  • daily wear
  • extended wear
  • disposable and
  • planned replacement contact lenses.

Definition[edit]

The U.S. Food and Drug Administration (FDA) states that:

Soft contact lenses are made of soft, flexible plastics that allow oxygen to pass through to the cornea. Soft contact lenses may be easier to adjust to and are more comfortable than rigid gas permeable lenses. Newer soft lens materials include silicone-hydrogels to provide more oxygen to your eye while you wear your lenses.[4]

Types of soft contact lenses[edit]

The U.S. Food and Drug Administration (FDA) classifies soft contact lenses into four groups for the U.S. Market. They are also subcategorized into 1st generation, 2nd generation, and 3rd generation lens materials.[5] These 'water-loving' soft contact lens materials are categorized as "Conventional Hydrophilic Material Groups ("-filcon"):

Group Water Content Percentage Ionic/Non-Ionic
I Low Water Content (<50%) Nonionic
II High Water Content (>50%) Nonionic
III Low Water Content (<50%) Ionic
IV High Water Content (>50%) Ionic

Note: Being ionic in pH = 6.0 - 8.0". This chart was published in the FDA Executive Summary Prepared for the May 13, 2014 Meeting of the Ophthalmic Devices Panel of the Medical Devices Advisory Committee.[6]

The FDA has been considering updating soft contact lens group types and related guidance literature.[7][8][9]

Contact lens polymers (hydrogel and silicone hydrogel materials)[edit]

The materials that are classified in the 5 FDA groups include the ones listed in the next 5 sections:[10][11]

History[edit]

The first contact lenses were made of a polymer called polymethylmethacrylate (PMMA) and became available in the 1960s. Lenses made of PMMA are called hard lenses.[12] Soft contact lenses made of polyacrylamide were introduced in 1971.[12]

FDA groups and brands[edit]

Below is a list of most contact lens materials on the market, their water percentage, their oxygen permeability rating, and manufacturer brands.[13][14][15][16] Note that the higher the oxygen transmissibility rating, the more oxygen gets to the eye.

Group 1 - Low Water (<50% H₂O) Nonionic Hydrogel Polymers[edit]

Material % Water Oxygen Transmissibility (Dk/t) Brands
Tefilcon 38 8.9 Cibasoft, Illusions, Torisoft, Softint, STD, LL Bifocal
Tetrafilcon A 43 9 Cooper Clear, Cooper Toric, Preference, Preference Toric, Vantage, Vantage Accents, Vantage Thin, Vantage Thin Accents
Crofilcon 38 13 CSI, CSI Toric
Helfilcon A/B 45 12 Continental Toric, Flexlens, Flexlens Toric, Flexlens Aphakic, Optima Toric, All X-Cel lenses
Mafilcon 33 4 Menicon
Polymacon 38.6 8.5-24.3 Allvue, Biomedics 38, Clearview, CustomEyes 38, EpconSOFT, EsstechPS, Esstech PSD, Esstech SV, Frequency 38, HD, HD-T, HDX, HDX-T, Horizon 38, Hydron Mini, Hydron Zero 4 SofBlue, Hydron Zero 6 SofBlue, Hydron Versa Scribe, Lifestyle MV2, Ideal Soft, Lifestyle Xtra, Lifestyle 4Vue, Lifestyle Toric Bifocal, LL38, Metrosoft ll Multifocal, Metrosoft Toric, Natural Touch, Occasions, Optima 38/SP, PS-45 Multifocal, Simulvue 38, Sof-form II, SofLens, SofLens38, SofLens Multi-Focal, Softics, SoftView, Unilens 38, Westhin Toric
Hioxifilcon B 49 15 Alden HP, Alden HP Toric, Aquaease, Essential Soft Toric Multifocal, Flexlens, Quattro, Satureyes, Satureyes Toric and Multifocal, All X-Cel Lenses

Group 2 - High Water (>50% H₂O) Nonionic Hydrogel Polymers[edit]

Material % Water Oxygen Transmissibility (Dk/t) Brands
Surfilcon A 74 35
Lidofilcon A 70 31 ActiFresh 400, CV 70
Lidofilcon B 79 38
Netrafilcon A 65 34.5
Hefilcon B 45 10 Optima Toric
Alphafilcon A 66 16 Soflens Toric for Astigmatism
Omafilcon A 58-60 28-36.7 Proclear 1-Day, Proclear EP, Proclear 1 day Multifocal, Proclear Multifocal Toric, Biomedics XC, Aveo
Omafilcon B 62 21.3-52.3 Proclear Sphere, Proclear toric, Proclear toric XR, Proclear multifocal, Proclear multifocal XR, Proclear multifocal toric
Vasurfilcon A 74 39.1 Precision UV
Hioxifilcon A 59 28 ExtremeH₂O 59% Thin/Extra, Biocurve Gold Sphere and Toric, Aura ADM
Hioxifilcon D 54 21 ExtremeH₂O 54%, Clarity H₂0, C-Vue Advanced Custom Toric
Nelfilcon A 69 26 Focus Dailies, Focus Dailies Toric/Progressive, Dailies AquaComfort Plus, FreshLook One-Day, Synergy, Triton
Hilafilcon A 70 35
Hilafilcon B 59 22 SofLens Daily Disposable, SofLens Daily Disposables for Astigmatism
Acofilcon A 58 25.5 Flexlens Tricurve Keratoconus
Nesofilcon A 78 42 Biotrue ONEday

Group 3 - Low Water (<50% H₂O) Ionic Hydrogel Polymers[edit]

Material % Water Oxygen Transmissibility (Dk/t) Brands
Bufilcon A 45 16 Hydrocurve II 45, Soft Mate B
Deltafilcon A 43 10 Amsoft, Amsoft Thin, Comfort Flex, Custom Flex, Metrosoft, Soft Form Toric
Phemfilcon 38 9 Durasoft 2

Group 4 - High Water (>50% H₂O) Ionic Hydrogel Polymers[edit]

Material % Water Oxygen Transmissibility (Dk/t) Brands
Bufilcon A 55 16 Hydrocurve I, Hydrocurve 3 Toric, Softmate II
Perfilcon A 71 34 Permalens
Etafilcon A 58 23.8-28 Acuvue, Acuvue Bifocal, Acuvue 2, Acuvue 2 Colors, 1-Day Acuvue, 1-Day Acuvue Moist, 1-Day Acuvue Moist for Astigmatism, 1-Day Acuvue Moist Multifocal, 1-Day Acuvue Define, Colornova, Discon, Waldo, Natural Vue
Focofilcon A 55 16 Fre-Flex
Ocufilcon B 52-53 16-24 ClearSight 1-Day, Continental, Ocu-Flex 53
Ocufilcon C 55 16 UCL55, UCL-Pediatric
Ocufilcon D 55 17.8-28.1 Biomedics 55, Biomedics 55 Premier asphere, Biomedics Toric, ClearSight 1-Day Toric
Ocufilcon E 65 22 Ocuflex 65
Ocufilcon F 60 24.3 Hydrogenics 60 UV
Phemfilcon A 55 16 Durasoft 3, Freshlook, Wildeyes
Methafilcon A 55 17.9-37.6 Biocurve Advanced Aspheric, Biocurve 1-Day, Biocurve Toric & Sphere, C-Vue 1-Day ASV, C-Vue 55, Edge III 55, Elite AC, Elite Daily, Elite AC Toric, Expressions Colors, Flexlens, Frequency 55 Sphere/Multifocal, HD2, HDX2, Horizon 55 Bi-Con, Hubble, Kontur, LL55, New Horizons, Revolution, Sauflon 55, Sof-form 55, Sunsoft Eclipse, Sunsoft Toric, Vertex Sphere, Vertex Toric
Methafilcon B 55 14.5-31.3 Frequency 55 Toric, Hydrasoft Sphere, Hydrasoft Sphere Thin, Hydrasoft Aphakic, Hydrasoft Aphakic Thin, Hydrasoft Toric, Hydrasoft Toric Thin
Vilfilcon A 55 16 Focus 1-2 Week Softcolors, Focus Monthly Softcolors, Focus Toric, Focus Progressives, Soft 55, Soft 55 EW

SiHy - Silicone Hydrogel Polymers[edit]

Material FDA Group % Water Oxygen Transmissibility (Dk/t) Brands
Lotrafilcon A 1 24 140 Air Optix Night & Day Aqua
Lotrafilcon B 1 33 110 O2Optix, Air Optix for Astigmatism, Air Optix Aqua, Air Optix Aqua Multifocal
Galyfilcon A 1 47 86[17] Acuvue Advance with Hydraclear, Acuvue Advance for Astigmatism
Senofilcon A 1 38 103-147 Acuvue Oasys, Acuvue Oasys for Astigmatism, Acuvue Oasys for Presbyopia, Acuvue Oasys 1-Day, Acuvue Oasys 1-Day for Astigmatism
Senofilcon C 41 129-147 Acuvue Vita, Acuvue Vita for Astigmatism
Sifilcon A 1 32 82 O2Optix Custom
Comfilcon A 1 48 116-160 Biofinity, Biofinity toric, Biofinity XR, Biofinity XR toric, Biofinity Energys, Biofinity multifocal
Enfilcon A 1 46 100 Avaira, Avaira Toric
Balafilcon A 3 36 91-130 PureVision, PureVision Toric, PureVision Multi-Focal, PureVision2, PureVision2 for Astigmatism, PureVision2 Multi-Focal for Presbyopia
Delefilcon A 33-80
(water gradient)
140 Dailies Total1
Narafilcon B 1 48 55 1-Day Acuvue TruEye (old)
Narafilcon A 46 118 1-Day Acuvue TruEye (new)
Stenfilcon A 54 80-100 MyDay, MyDay toric
Somofilcon A 56 57-86 clariti 1 day, clariti 1 day toric, clariti 1 day multifocal
Fanfilcon A 55 90-110 Avaira Vitality, Avaira Vitality toric
Samfilcon A 46[18] 114-163[19] Bausch & Lomb Ultra, Bausch & Lomb Ultra for Astigmatism, Bausch & Lomb Ultra for Presbyopia
Elastofilcon 0.2 340 (Dk) SilSoft Aphakic, SilSoft Super Plus

Production generations[edit]

There are three generations of silicone hydrogel contact lens materials:[20]

1st Generation 2nd Generation 3rd Generation
Material: Lotrafilcon A, Balafilcon A Senofilcon A, Galyfilcon A Samfilcon A, Comfilcon A, Enfilcon A
Features: TRIS structures, plasma treated, high modulus Modified Tanaka monomer, lack of coatings, higher Dk for water content No TRIS structure, no surface treatments or wetting agents, breaks traditional water-Dk-modulus relationships

References[edit]

  1. ^ Denise Hampton, Ph.D (13 May 2014). "Contact Lens Safety - Ophthalmic Devices Panel" (PDF). www.fda.gov. FDA Division of Ophthalmic and Ear, Nose and Throat Devices. p. 97. Archived from the original (Microsoft PowerPoint) on 18 Jun 2016.
  2. ^ "About Contact Lenses - clma.net". clma.net. Contact Lens Manufacturers Association. Retrieved 18 June 2016.
  3. ^ "Caring for Your Vision: Advantages and Disadvantages of Various Types of Contact Lenses". www.aoa.org. American Optometric Association. Retrieved 18 June 2016.
  4. ^ Center for Devices and Radiological Health. "Contact Lenses - Types of Contact Lenses". www.fda.gov. U.S. Food and Drug Administration. Retrieved 18 June 2016. This article incorporates text from this source, which is in the public domain.
  5. ^ http://www.aalens.com/fda.html
  6. ^ Ophthalmic Devices Panel of the Medical Devices Advisory Committee (May 13, 2014). "FDA Executive Summary Prepared for the May 13, 2014 Meeting of the Ophthalmic Devices Panel of the Medical Devices Advisory Committee" (PDF). U.S. Food and Drug Administration. p. 2. Archived from the original (PDF) on 7 Aug 2015. Retrieved 18 June 2016.
  7. ^ LORETTA B. SZCZOTKA-FLYNN, OD, MS, FAAO (1 Feb 2005). "Contact Lens Materials: Advocating a New Lens Group". Contact Lens Spectrum. Contact Lens Spectrum - February 2005 Issue. Archived from the original (Journal Article) on 6 Oct 2015. Retrieved 18 June 2016.CS1 maint: Multiple names: authors list (link)
  8. ^ "Contact Lens Compendium". contactlensupdate.com. Contact Lens Spectrum. Retrieved 18 June 2016.
  9. ^ Tina Kiang, PhD; Joseph Hutter, PhD; J Angelo Green, PhD; K Scott Phillips, PhD; Malvina B Eydelman, MD (10 Nov 2011). "Updating the Contact Lens Classification System" (PDF). www.fda.gov. http://www.fda.gov/cdrh/devadvice: FDA Center of Devices and Radiological Health. p. 38. Archived from the original (PPT) on 17 Nov 2011.
  10. ^ "Contact Lenses: Manufacturing/Chemistry" (PDF). www.fda.gov. U.S. Food and Drug Administration. n.d. p. 25. Archived from the original (PDF) on 15 May 2015. Retrieved 18 June 2016.
  11. ^ "Editorial - Should Silicone Hydrogels be Placed in a Separate FDA Soft Contact Lens Category?". www.siliconehydrogels.org. Retrieved 18 June 2016.
  12. ^ a b "Polymers in everyday things – Contact Lenses" (PDF). rsc.org. Royal Society of Chemistry. Archived from the original (PDF) on 19 June 2016. Retrieved 19 June 2016.
  13. ^ "Contact Lens Spectrum - Soft Contact Lenses". www.clspectrum.com. Contact Lens Spectrum. Retrieved 19 Feb 2019.
  14. ^ "CooperVision Product Reference Guide - 2019" (PDF). coopervision.com. CooperVision. Retrieved 19 Feb 2019.
  15. ^ "Acuvue Tech Specs - Winter 2017" (PDF). www.acuvue.com. Johnson & Johnson. Retrieved 19 Feb 2019.
  16. ^ "Contact Lenses : Bausch + Lomb". www.bausch.com. Bausch & Lomb. Retrieved 19 Feb 2019.
  17. ^ Dr. Karen French (12 May 2008). "The Performance of Galyfilcon A" (PDF). OpticianOnline.Net. Contact Lens Monthly. Retrieved 18 June 2016.
  18. ^ AVID L. KADING, OD, FAAO. "New Lens Technology Targets Improved Vision and Comfort: Samfilcon A - Contact Lens Design & Materials". clspectrum.com.CS1 maint: Multiple names: authors list (link)
  19. ^ "Product Spectrum: Unsurpassed Comfort and Vision the Goal with Monthly SiHy Lens". clspectrum.com. Contact Lens Spectrum. Retrieved 18 June 2016.
  20. ^ "Looking at Silicone Hydrogels Across Generations". www.optometricmanagement.com. Optometric Management. Retrieved 18 June 2016.