1 / 36

EVOLUTION OF REFRACTIVE SURGERY

EVOLUTION OF REFRACTIVE SURGERY. Types of Refractive Surgery. Incisional - RK, AK, ALK Laser - PRK, LASIK, LASEK, Epi LASIK Corneal - Intacs Intraocular - Refractive Lensectomy, Phakic IOLs, etc. Evolution of Refractive Surgery. Corneal Inlay’s. RK. PRK. LASIK. Most Recent Advances

wilona
Download Presentation

EVOLUTION OF REFRACTIVE SURGERY

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EVOLUTION OF REFRACTIVE SURGERY

  2. Types of Refractive Surgery • Incisional - RK, AK, ALK • Laser - PRK, LASIK, LASEK, Epi LASIK • Corneal - Intacs • Intraocular - Refractive Lensectomy, Phakic IOLs, etc.

  3. Evolution of Refractive Surgery Corneal Inlay’s RK PRK LASIK Most Recent Advances CK- Conductive Keratoplasty CustomLASIK- Wavefront Guided Laser Ablation Refractive Intraocular Lenses Epi LASIK Multifocal Ablations

  4. Incisional/Ablative Procedures PRK LASIK RK Permanent alterations to Central Optical Zone

  5. Incisional Refractive Procedures • Radial Keratotomy / Astigmatic Keratotomy • Oldest of elective refractive procedures • Popular during 1980’s • Some resurgence just before Laser approved • Problems: • Weakens Globe • Many side effects – long term fluctuation of vision, halo’s, glare, progression of effect • Limited Application – low to moderate myopia and astigmatism

  6. RK - RADIAL KERATOTOMY

  7. RK - RADIAL KERATOTOMY

  8. TOO MUCH RK

  9. MYOPIC KERATOMILEUSIS • MKM - Myopic Keratomileusis - used a microkeratome to resect a thick corneal cap which was frozen, lathed, and sutured onto the cornea

  10. Incisional Refractive Procedures • Automated Lamellar Keratoplasty • Could treat both myopia and hyperopia • Required a microkeratome to create a corneal flap and, when correcting myopia, to remove a small disk of corneal tissue • Predecessor to LASIK

  11. ALK - AUTOMATED LAMELLAR KERATOPLASTY • Use of ACS (Automated Corneal Shaper) to remove a thin resection of tissue causing central flattening for treatment of myopia.

  12. ALK Advantages Over Previous Procedures • Treat high degrees of myopia as well as low amounts of hyperopia • Get a patient in the “range” of RK • Healing advantages • Rapid vision rehabilitation • Minimal healing influences • Minimal discomfort

  13. Ablative Refractive Procedures • Photorefractive Keratectomy (PRK) • First refractive procedure to use the excimer laser • Can treat myopia, hyperopia and astigmatism • Patient can have significant discomfort in early postop period due to removal of epithelium • Slow visual recovery • Patients normally treated one eye at a time • Mitomycin C sometimes used to lessen haze/scarring

  14. PRK Procedure

  15. PRK – For Treatment of Myopia

  16. PRK Advantages Over Previous Procedures • Increased Accuracy over MKM • Reduced Surgical Learning Curve • Practitioner Friendly

  17. Disadvantages of PRK • Mild Discomfort • Increased time to best uncorrected vision • Outcome is not completely predictable • Possible Under or Overcorrection • Could result in a retreatment or enhancement • Possible corneal haze effecting vision

  18. Combination – Incisional & Ablative Procedure • Laser In Situ Keratomileusis - LASIK • Uses a flap maker to create a protective flap of corneal tissue and the excimer laser to treat the refractive error • Combined the accuracy of the laser with the quicker visual recovery of ALK

  19. LASIK

  20. LASIK

  21. ADVANTAGES OF LASIK OVER PRK • Bilateral Friendly • Many PRK Healing Risks Avoided • Less, but more rapid regression • Stable results • Patient friendly

  22. Disadvantages of LASIK • Intraoperative flap complications • Incomplete flaps or caps • Postoperative flap complications • Striae (wrinkles in the flap) • Ingrowth • Diffused Lamellar Keratitis (DLK or Sands) • Possible Over or Undercorrection • Enhancement for residual refractive error

  23. Clear enough? ONE DAY!

  24. Similar to PRK Epithelial flap is created either mechanically or manually and moved to expose the stroma for laser treatment and then repositioned Potential less pain than PRK. Alternative for patients with large pupils & thin corneas. LASEKLaser Epithelial Keratomileusis

  25. LASEK • Thinner flap consisting of the Epithelium Layer only • How thick is the Epithelium? • Less chance of Ectasia (thinning of the cornea) • More dependence of healing • Comfort of LASIK – Safety of PRK

  26. Epi LASIK • Very similar to LASEK • Mechanical device used to create Epi Flap • Cleaves or separates Epithelium from Bowmans Membrane • Delicate, thin flap

  27. Corneal Inlay’s Intacs • Treats low amounts of myopia and keratoectasia • Two arch shaped inlays surgically placed in periphery of cornea, outside the optical zone for refractive procedures • Seldom used technology for refractive surgery, but being revisited for “Niche” procedures in Keratoectasia treatment

  28. LTK- Laser Thermal Keratoplasty • Holmium:YAG Laser (Sunrise) • Circular pattern of small thermal spot treatments to steepen the central cornea. • Designed for Hyperopia. • Limited treatment range. • Temporary Affect

  29. Conductive Keratoplasty - CK • Circular Zones of small “radio wave” spot treatments to steepen the central cornea • Approved for Hyperopia and Presbyopia • Limited Range of correction and control • Unplanned Benefit of Multi-focality • Presbyopic positive side-effect

  30. SCLERAL EXPANSION BANDS • Designed to treat presbyopia • Not FDA approved • Theory: presbyopia is due to slackening of fibers attached to the lens. • Above: Implanted scleral expansion band (full circular band model) • Below: Scleral expansion bands compared with a penny (band segment model)

  31. CustomLASIK • A.K.A WaveFront Guided Laser Ablation • Wavefront Aberrometer Required. • Correct Sphere and Cylinder and small imperfections (High Order Aberrations) • Improved Visual Quality (less halos and glare.) • Improved Night Vision.

  32. REFRACTIVE LENSECTOMY • Alternative for patients not qualified for cornea refractive procedures or patient with early lenticular changes • Similar to cataract surgery: natural lens is removed & artificial lens is implanted. • Instant Presbyopia • Accomodating IOL’s possibility to retain near vision

  33. PSEUDOPHAKIC INTRAOCULAR LENSES THAT MAINTAIN ACCOMMODATION • Alternative for patients not qualified for corneal refractive procedures or have existing cataracts. • Permanent implant inside the eye. • Replaces natural lenses • Pt retains accommodation through special ‘hinges’ Example: Crystalens™

  34. PHAKIC INTRAOCULAR LENSES • Alternative for patients not qualified for corneal refractive procedures • Permanent implant inside the eye. • Can be positioned in the anterior chamber or posterior chamber in front of the natural lens. • Pt retains accommodation

  35. Summary • LASIK is the dominant corneal refractive procedure • The key to ultimate patient care is knowing advantages/disadvantages of each option

More Related