The document provides an introduction to refractive surgery, describing different types of refractive errors and methods used to correct them. It discusses procedures like LASIK, PRK, and lens implants. LASIK involves creating a corneal flap then sculpting the cornea with an excimer laser. PRK removes the outer corneal layer then applies the laser. Lens implants are for higher refractive errors or when other methods don't work. The risks, recovery times, and potential outcomes are outlined for each procedure.

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

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

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

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

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

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

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

78. What is best for you? Consider your personal preference and lifestyle.

79. THANK YOU