LASIK: How It’s Done
Vincent J. Marino, D.O. FAOCOMedical Director, LASIKPlus Cincinnati & Dayton, OH
7840 Montgomery Rd. Cincinnati, OH 452366470 Centerville Business Parkway, Centerville, OH 45459
LASIK: How It’s DonePretest Question #1
What percentage of LASIK patients achieve uncorrected visual acuity of 20/40 vision or better? A. 99% *B. 94%C. 75%D. 50%
LASIK: How It’s DonePretest Question #2
• What group below best describes the population that acquires presbyopia (age related loss of near vision)?
A. Presbyopia only effects some people over the age of 40.
B. Presbyopia effects all individuals over the age of 40 regardless of glass prescription. *
C. Presbyopia only happens to your parents.D. Myopic (nearsighted) individuals can not become
presbyopic.
20th Annual Grandview Family Practice Conference
February 20, 2015 • Vincent J. Marino, DO• 1992 - Nova Southeastern University College of
Osteopathic Medicine • 1993 - Internship Grandview Hospital • 1996 - Residency Ophthalmology Grandview
Hospital • Fellow American Osteopathic College of
Ophthalmology• 1996 – Present, LASIKPlus Cincinnati & Dayton,
OH • Experience 86,000 LASIK surgeries
LASIK• LASIK: acronym l(aser) as(sisted) i(n-situ)
k(eratomileusis)• eye surgery to correct vision in which a laser
reshapes the inner cornea.
Why does one undergo elective refractive
surgery?
• Has a Myopic, Hyperopic, Astigmatic refraction (glasses Rx).
Why does one undergo elective refractive
surgery?
• Tired of wearing glasses• More than 150 million Americans use corrective
eyewear to compensate for refractive errors. 1
Why does one undergo elective refractive
surgery?
• Contact lens intolerant or over wears contact lenses. • More than 30 million people in the U.S. wear contact
lenses. • Serious eye infections that can lead to blindness affect
up to 1 out of every 500 contact lens users per year.• Not following proper contact lens care instructions• Between 40%-90% of contact lens wearers do not
properly follow the care instructions for their contact lenses.
• Improper cleaning and irregular replacement of contact lenses and contact lens cases—as well as other behaviors relating to contact lens hygiene and care—have been linked to a higher risk of complications.
Why does one undergo elective refractive
surgery?
• Activities that makes contacts or glasses hard to wear
• Job (firefighting, police), Military, sports
History of refractive surgery 4
• 1988 Marguerite B. McDonald, MD First PRK • 1989 Gholam A. Peyman, MD patent on flap
production
• 1999 LASIK formally approved by the FDA
Elective surgery
• LASIK is the world’s most popular elective procedure—more than 28 million LASIK procedures have been performed worldwide.
Candidacy
• Good medical health, good ocular health, good topography, good pachymetry (corneal thickness)
• > 18 years and stable refraction• Insure that healing for an elective surgery may go
well.• Rx in range =/- 0.75D or greater.• Up to -11.00 Diopers of Myopia• Up to +5.00 Diopters of Hyperopia• Up to -6.00 Diopters of Astigmatism
Candidacy• Refractive Range• Measured in units of optical units Diopter (D)
o 1 Diopter = 1/meter (f)
<--------(+6D)------hyperopia--------0--------myopia-------- (-11D)------->
Emmetropia = +/- 0.5 D
Astigmatism 0 ------------------------------(-6 D)------>
Evaluation
• Medical and family history • Dilated eye exam• Refraction objective and subjective • IOP (intra ocular pressure)• Corneal Topography • Aberrometry• Pachymetry (corneal thickness)
EvaluationTopography
EvaluationAberrometry
Consent • Goals and expectations (20/40 or better, most will
achieve 20/20 or better)• Review enhancement limits, may do second
surgery if Rx drifts (3-4%) if Rx drift. Usually less than one Diopter.
• Presbyopia education (over 40 years, need reading glasses if both eyes are corrected for distance).
• Monovision option• Review risk, benefits and alternatives
Presbyopia• Near Vision reflexoConvergenceoPupil constrictionoAccommodation• Loss of accommodation due to age = presbyopia
Presbyopia• Loss of near vision due to age
o Loss of accommodation (focusing power) o All individuals regardless of refractiono 40 years and oldero Progressive
• Results from the thickening and loss of flexibility of the natural lens• Stabilizes in mid-sixties
o Myopes with a refractive range of -1.00 to -3.00 diopter can read without glasses.• Myopes become presbyopic and experience blurred vision at near
with their spectacle (eye glass) correction.
Presbyopia Monovision
• Optional treatment method to decrease the dependence on glasses for both distance and near vision for individuals over 40 years.
• Dominant eye is corrected for distance• Non Dominant eye is corrected for near• Monovision can be set up with contact lenses or
LASIK• “Blended vision”• Functional vision, not perfect at distance or near.• Compromise, “best of both worlds”.• Monovision patients may require part time glasses for driving and fine
near vision.
Equipment
• Flap production• Femtosecond laser VS Microkeratome• Microkeratome: Buttonhole, partial flap, suction
loss, less stable refractive outcome re non-planar flap (thinner in the middle)
• Femtosecond laser: scars may yield incomplete
flaps but are rare. Able to reapply suction after suction loss and complete flap. More stable refractive outcomes. Lower incidence of dry eye. Ability to produce thinner flaps to conserve corneal tissue and provide higher refractive treatments.
Surgery
Microkeratome blade inspection
Surgery Microkeratome
assembled
SurgeryFemtosecond laser
Equipment Femtosecond laser
SurgerySurgical instruments
Excimer laser • Visx, • Wavelight
Surgery
• Proparicaine anesthetic • drops last 30 minutes
Surgery
• Flap production
Surgery• Flap dissection and lift
Surgery• Excimer laser • refractive ablation
Surgery• Flap reposition
Surgery• Removal of debris• Slit lamp
Surgeryflap production suction
ring
Surgeryflap production suction
ring
Surgeryflap production
docking
Surgeryflap production
docking
Surgeryflap production
Surgeryflap production
Surgeryflap production
Post Operative follow up and care
• Rest for four hours with eyes closed mild burning expected
• No eye rubbing• No swimming or hot tubs for one week• Inflammation and infection warning signs given• Diving vision expected at day one• Antibiotic and steroid drops for one week
Recovery
• Post Operative follow up and care:• Rest for four hours with eyes closed mild burning
expected• Diving vision expected at day one• Antibiotic and steroid drops for one week
Recovery• Most patients achieve 20/40 to 20/20 (driving
vision) the next day. Most patients report near glasses like vision on day one. The quality of their vision improves dramatically through the weeks one to 12. Complete refractive stability occurs at about one year.
Recovery• Patients are instructed not to rub their eyes for
one week to prevent the flap from being dislodged (a rare complication but easily repaired). Protective safety glasses are worn during sleep for the first week.
Post Operative follow up and care
• One day o Ensure that the flap is in good positiono Dry eyeo inflammationo Infection
• One montho Refractive outcomeo Dry eye
• Three monthso Refractive outcomeo Dry eye
• Annual examso Insure good ocular health and refractive stability
Outcomes
• 94% 20/20 or better• 99% 20/40 or better• 3-4 % enhancement rate (second surgery)
o Uncorrected visual acuity 20/30 or worseo Manifest (subjective) refraction +/- 0.75 Diopterso Difficulty with night vision o Refractive shift over timeo residual refraction
Patient satisfaction
• 95% of patients are satisfied and have no further need for additional surgery.
• 3% require enhancement (second surgery)o Reasons: patient expectations and refractive shift.o most second surgeries occur years to decades
secondary to small Rx shifts.
Complications
• Dry eye• Diffuse Lamellar Keratitis• Ectasia• Flap Complications• Suspicious settings
Future of LASIK
• Topography guided treatments for asymmetric corneas
• cross linking for ectasia and keratoconus
PRK
• Surface laser without the flap