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Implantable collamer lens(ICL)

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Implantable collamer lens(ICL)

  1. 1. Implantable Collamer lens(ICL) Dr Samuel Ponraj
  2. 2.  ICL is made from 100 % biocompatible soft flexible gel lens  The material porcine Collagen is polymerised with HEMA Hence collagen copolymer = Collamer  Posterior chamber Phakic IOL model
  3. 3. History Fathers of Phakic IOL – Choyce,Strampelli, Barraquer conduted first ever trials using AC refractive lenses to correct high myopia in 1950s.  But due to unacceptable complications such as loss of corneal endothelial cells,iris atrophy, PAS , these especially the angle supported lenses were phased out of the market. 
  4. 4. First model made by Fyodorov in 1980s in Russia of a collar button configuration.  First implant in Europe in 1993.  Concept of soft phakic lens. 
  5. 5.  This material of Collamer was made by STAAR Visian Surgicals which provide good biocompatibility ,Optical capability, with a lens resting behind the iris in ciliary sulcus.
  6. 6. Prerequisites Residual bed after LASIK < 250 microns  Initial Corneal thickness < 480 microns  Stable refraction <0.5 D change in previous 12 months  No ocular pathology 
  7. 7. 3 variants of Phakic IOL  Angle supported and Iris claw lenses are the AC variants.  ICL is the PC variant.  Due to reasons of complications associated with ACIOL design 
  8. 8. FDA approved its use in Myopia and Myopic astigmatism in year 2005 via NEI sponsored study.  Indication in  Myopia of -3 to -25 Dioptres  Astigmtism up to – 6 Dioptres  Thin Corneas 
  9. 9. Measurement of white to white diameter Using Orbscan,UBM or calipers  Add 0.5 mm to horizontal WW measurement for ICL overall length  ICL too short – lens vault less, exposes to risk of Anterior capsular cataract  ICL too long – lens vault exceeds – angle crowding –closed angle glaucoma 
  10. 10. Vault:  Ideally should be 500 microns= one corneal thickness High vault - Iris chaffing pigment dispersion,glaucoma Low vault - ICL contact with crystalline lens – cataract formation.
  11. 11. Procedure Under topical anaesthesia ,0.6 mm side port , 3.2 mm clear corneal incision on steep meridian.  Lens introduced into the soft silicone tip with micro incision injector and positioned behind iris with help of blunt spatula.  Lens is implanted temporally and gently rotated to align the axis with the cylindrical axis of the patient. 
  12. 12. Complete removal of viscoelastic material  Miotic agent injected  Incision closed by hydrating incision  Peripheral iridotomy – intraoperatively with vannas scissors ,sufficiently wide, positioned superiorly , well away from haptics – to provide outlet for aqueous flow around lens.
  13. 13. Reports  Kamiya et al in a studied the long term clinical outcomes of implantation of these implantable lenses for Myopia in 56 eyes of 34 patients with refractive errors of - 4.00 to – 15.25 D . Kamiya K, Shimizu K . Implantable Collamer lens for hyperopia after radial keratotomy . J Cataract Refract Surg 2008; 34(8) : 1403-4
  14. 14.  They concluded implantation is safe and effective with predictable and stable refrative results during a four year observation period.
  15. 15.  Kamiya et al also compared Collamer toric ICL with wavefront guided LASIK for high myopic astigmatism and found that all eyes in ICL group and 71 percent in LASIK were within +/- 1.00 D of targetted SE correction at six months.
  16. 16. Hence it was concluded that these Toric ICLs were superior compared to LASIK in all measures of safety, efficacy predicability,stability.  Thus overall complication rate was low and patients have good visual recovery. 
  17. 17.  According to a study by Sanders et al ,the incidence of anterior subcapsular opacities and cataracts were studied after ICL implantation.Approximately 6 – 7 % of eyes developed anterior subcapsular opacities at over 7 yrs but 1 % progressed to cataract. Sanders DR. Anterior subcapsular opacities and cataracts 5 years after surgery in the visian collamer lens FDA trial . J Refract Surg 2008;24(6): 566-70
  18. 18.  With the advancements in anterior segment imaging , ultrasonic biomicroscopy , Optical coherence tomography and Scheimpflug imging ,valuable information is now provided about anterior segment anatomy for phakic Intraocular lenses(ICL) for correction of moderate to high refractive errors.
  19. 19. Advantages The procedure is reversible unlike LASIK  The quality of vision is usually better  It creates a small corneal incision so astigmatism is minimum  Corneal tissue is not removed ,hence adequate tear layer  Reduction of risk of optical distortions an higher order aberrations 
  20. 20. THANK YOU

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