Fatima refractive surgery lecture

  • 7,473 views
Uploaded on

 

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
No Downloads

Views

Total Views
7,473
On Slideshare
0
From Embeds
0
Number of Embeds
1

Actions

Shares
Downloads
586
Comments
2
Likes
9

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Introduction to Refractive Surgery Richard L. Nepomuceno, MD Diplomate, Philippine Board of Ophthalmology Cornea, External Disease & Refractive Surgery Fatima Medical Center . St. Lukes Medical Center . Capitol Medical Center East Avenue Medical Center . Manila Central University Cardinal Santos Medical Center . Manila Doctors Hospital
  • 2.  
  • 3. Errors of Refraction or Ametropia
    • Problems in the focusing mechanism of the eye
    • causes blurred vision because light or image is not focused on the retina
  • 4. Emetropia
    • NORMAL state of the eye
    • light or image is focused on the retina
    • resulting in clear and sharp vision.
  • 5. Human Eye = Camera
    • Cornea = outer lens of the camera
    • Pupil = aperture of the camera
    • Lens = inner lens of the camera
    • Retina = film of the camera
  • 6. What affects focusing function of the eye?
    • Shape of the cornea (steep, flat, oblong, irregular)
    • Shape and thickness of the crystalline lens
    • Length of the eyeball
  • 7. Types of Errors of Refraction
    • Near sightedness or myopia ( minus )
    • Far sightedness or hyperopia or hypermetropia ( plus )
    • Astigmatism
    • Mixed types
    • Presbyopia (reading glasses)
  • 8. Near Sightedness
    • Far objects = blurred
    • Near objects = clear
    • light is focused IN FRONT of the retina
    • Due to :
      • long eyeball
      • steep cornea
      • thick lens
      • combination of the above
  • 9. Near Sightedness
  • 10. Far Sightedness
    • Far objects = clear
    • Near objects = blurred
    • light is focused BEHIND the retina
    • Due to:
      • short eyeball
      • flat cornea
      • thin lens
      • or combination of above
  • 11. Far Sightedness
  • 12. Astigmatism
    • Both far and near objects appear blurred or have a shadow or double image
    • light is split and falls at different location from the retina
    • due to corneal shape (football instead of basketball)
  • 13. Astigmatism
  • 14. Presbyopia
    • Difficulty in reading small prints
    • normal process due to aging
    • occurs around age 40
    • due to weakening of the crystalline lens to focus near objects
    • people with normal vision or far sighted will need reading glasses
    • near sighted people will have to remove their distance glasses
  • 15. History of Vision Correction Surgery
    • Dr. Jose Barraquer of Colombia (1949)
      • Discovered that lamellar (layered) corneal surgery could reshape the cornea to enhance focus
      • Keratomileusis – a microkeratome(blade) removes a disc of the front portion of the cornea. Freezes and reshapes it, then puts it back.
  • 16. History of Vision Correction Surgery
    • Dr. Casimir Swinger (1985)
      • nonfreeze keratomileusis
    • Dr. Luis Ruiz
      • Automated Lamelar Keratoplasty (ALK) - automated microkeratome to reshape the cornea directly on the eye
  • 17. Automated Lamellar Keratoplasty (ALK)
    • For high myopes prior to Excimer laser
    • Flap is created by microkeratome
    • Second pass with microkeratome to remove corneal tissue
    • Less precise, higher complications than LASIK
    • High percentage need additional procedures to achive desired results
  • 18. Arrival of the Excimer Laser
    • First used in human eyes in the late 80’s
    • Cool ultraviolet beam of light to vaporize tissue with great precision, w/o harming adjacent tissue
  • 19. Photorefractive Keratectomy (PRK)
  • 20. Photorefractive Keratectomy (PRK)
    • First widely used procedure with the excimer laser (1987)
  • 21. Photorefractive Keratectomy (PRK)
    • Outer layer of cornea is removed then laser is applied
    • vision improves as surface heals after 4 to 7 days
    • discomfort present during healing
    • can cause corneal scarring
  • 22. PRK for Myopia
  • 23.  
  • 24. Photorefractive Keratectomy (PRK)
    • No microkeratome involved
    • No flap created
    • Ultimate visual results similar to LASIK
    • Longer recovery period (> 2 weeks)
    • Complications similar to LASIK; Haze
  • 25. Photorefractive Keratectomy (PRK) HAZE
  • 26. Laser In-situ Keratomilieusis (LASIK) Las er – performed with Excimer Laser I n situ – the cornea in its natural position on the eye K eratomileusis – carving the cornea to reshape it
  • 27. LASIK
    • Started in 1991
    • US Clinical Trials started in 1996
    • FDA approval in 1999
  • 28. LASIK
    • Thin outer corneal flap made with high speed blade
    • flap is lifted then laser is applied to sculpt cornea
    • corneal flap is then returned
    • immediate visual improvement
    • almost no discomfort
    • early adjustment can be done
  • 29. LASIK
  • 30. LASIK
  • 31. LASIK
  • 32.  
  • 33. LASIK
  • 34. LASIK
  • 35. Laser Subepithelial Keratectomy (LASEK)
    • Hybrid between PRK and LASIK
    • “Flap” of epithelium
    • ZERO “flap” complications of LASIK
    • Slightly faster recovery than PRK
    • Less incidence of haze than PRK
    • Results similar to PRK and LASIK
  • 36. Advantages of Excimer Laser
    • Safe, quick and effective if properly done
    • corrects near and far sightedness and astigmatism
    • removes or decrease need for glasses or contact lenses
    • long lasting result
    • external eye surgery
    • US - FDA approved
  • 37. Disadvantages of Excimer Laser Surgery
    • Not ideal for very high degrees of errors
    • relatively expensive
    • presence of surgical risk
    • not reversible
    • glare, halo or night vision problems
    • delayed healing or scarring
    • no 100% guarantee
  • 38. Am I a good candidate?
    • Stable refraction (< 0.50 D) for at least one year
    • Ideal age 18 or 21 years old and above
    • Degree of correction* :
      • Myopia (-0.75 to -12D)
      • Hyperopia (+6D)
      • Astigmatism (6D) * depends on patient, surgeon, machine, procedure
  • 39. Am I a good candidate?
    • Surgically ideal eyes :
      • Normal sized pupils < 7 mm at night
      • Nomal corneal thickness (> 500 u m )
      • Stucturaly normal eye (not irregularly shaped like keratoconus, etc)
      • Healthy pressure within the eye
      • Generaly Health eyes ( eye diseases or injuries that could interfere)
  • 40. Am I a good candidate?
    • Watch out for these health conditions :
      • pregnant, about to get pregnant or breast feeding if female
      • Collagen Vascular Diseases – Cornea has collagen
      • Glaucoma or Cataracts
      • Certain corneal dystrophies
      • Herpetic keratitis
      • Diabetic retinopathy
      • Lupus, diabetes, rheumatoid arthritis must be controlled an identified
  • 41. Other Health conditions :
    • Prescription Medicines that May Cause Problems :
      • Accutane ( for acne) – may cause severe dry eye and decreased night vision
      • Oral Prednisone – may lower resistance to infections
    • UNREALISTIC expectations
  • 42. Is It Painful
    • No. The eyes are numbed with eyedrops
    • LASIK – slight pressure during suction
    • After surgery :
      • Some FB sensation a few hours after LASIK
      • Some scratchiness for 2- 4 days for PRK
  • 43. How Long does LASIK Take ?
    • 5-10 minutes
  • 44. How Long will it take for my eyes to heal for LASIK?
    • Compared to others, it is fast
    • Most postoperative discomfort and visual side effects are minor
    • Watery sensation a few hours after surgery
    • Rarely any significant discomfort the following day
    • Good vision the following day.
    • Vision improves for 2-6 months until stable
  • 45. When can I go back to work after LASIK
    • Most patients can go back to work the following day.
    • If work environment very dusty, wait about 48 hours
  • 46. How long will the correction last?
    • Usually, LASIK, PRK, LASEK will correct distance vision permanently
    • Eyesight changes slightly over time
    • Not because the procedure was unstable but because our eyes change
    • Enhancement procedures are normal (5-10%)
  • 47. Excimer laser corneal refractive surgery does NOT prevent or reduce the risk of cataract, glaucoma and retinal degeneration or detachment.
  • 48. Excimer laser corneal refractive surgery does NOT prevent or treat the development of presbyopia.
  • 49. Radial Keratotomy (RK)
    • Myopia
    • Series of 4-8 radial microscopic incisions on surface of Cornea to change curvature
  • 50. Radial Keratotomy
  • 51.  
  • 52. Astigmatic Keratotomy (AK)
    • Similar to RK
    • For astigmatism only
    • 1-2 incisions along periphery of cornea
    • For pure astgmats
    • May be combined with LASIK, PRK, LASEK, Cataract extraction.
  • 53. Astigmatic Keratotomy
  • 54.  
  • 55. Intacs Corneal Ring Segments
    • FDA Approved 1999
    • < 3.0 D myopia w/ < 1.0D Astigmatism
    • 2 small plastic ring segments placed on periphery of cornea
    • Removable
  • 56. Intacs Corneal Ring Segments
  • 57. Intacs Corneal Ring Segments
  • 58.  
  • 59. Intraocular Lens Implant
    • Placement of artificial plastic lenses inside the eye to correct errors of refraction
  • 60. Cataract Surgery
  • 61. Clear Lens Extraction
    • Remove lens as in cataract surgery
    • For patients > 40 y.o.
    • Disadvantage : intraocular surgery,no accomodation, risk of Retinal Detachment
  • 62. Advantages of Lens Implant
    • Artificial lenses are safe and effective
    • good for high degrees of errors
    • minimal visual distortions
    • near immediate result
    • lifetime effect
    • no maintenance
    • reversible and adjustable (some types)
  • 63. Disadvantages of Lens Implant
    • Internal eye surgery
    • greater surgical risk
    • risk of late retinal detachment
    • risk of late corneal damage
    • relatively expensive
  • 64. Phakic Intraocular Lens (PIOL) Implants
    • For extreme nearsightedness ( greater than -12D to -15D) / farsightedness (greater than +4D to +6D )
    • Advantage : maintains accomodation
    • Disadvantage : may develop cataracts;endophthalmitis
  • 65. Phakic Intraocular Lens (PIOL) Implants
  • 66. Bioptics
    • Phakic IOL implant then LASIK
    • When neither technique alone works
    • Can correct more than 30D of myopia
  • 67. HYPEROPIA
  • 68. PRK for Hyperopia
  • 69. Laser Theramal Keratoplasty (LTK)
    • FDA approval Jan 2000
    • Holmium laser – deliver laser energy to periphery of cornea
    • For Hyperopia (0.75 to 2.5 D)
    • Takes months to stabilize
    • In time, the effect wears off in a substantial number of cases
  • 70. Laser Theramal Keratoplasty (LTK)
  • 71. Conducktive Keratoplasty (CK)
    • A special probe introduces electrical current to the peripheral cornea, shrinking the collagen to tighten the cornea and make it steeper centrally
    • FDA approved 2002
  • 72. Conducktive Keratoplasty (CK)
  • 73. Conducktive Keratoplasty (CK)
  • 74. Presbyopia
    • To date, there is still NO widely accepted, safe and effective permanent treatment for this condition
  • 75. Surgery for Presbyopia
    • Anterior Ciliary Sclerectomy (ACS)
    • Scleral Expansion Bands (SEBs)
  • 76. VIDEO
  • 77.  
  • 78. What is best for you? Consider your personal preference and lifestyle.
  • 79. THANK YOU
  • 80.