LASIKLASIK

Aravind Eye Hospital,Aravind Eye Hospital,

TirunelveliTirunelveli

-Technological explosion in field ofTechnological explosion in field of

refractive surgery refractive surgery -25 years later, 20 different refractive25 years later, 20 different refractive

surgical techniques surgical techniques

- Lasik currently most widely used - Lasik currently most widely used

IntroductionIntroduction

IndicationsIndications

a)a) Myopia (-1-to-15D)Myopia (-1-to-15D)b)b) Hypermetropia (+1-to+8D)Hypermetropia (+1-to+8D) need for modification of current algorithms & need for modification of current algorithms &

better ablation profile to improve better ablation profile to improve predictabilitypredictability

c)c) Astigmatism:Astigmatism: - range from – 0.5 D.- range from – 0.5 D.

- in mixed astig may not be possible to - in mixed astig may not be possible to correct in a single ablationcorrect in a single ablation

Pre Operative assessmentPre Operative assessment

Patient selectionPatient selection

- Vital importance- Vital importance

- patient education- patient education

- practical knowledge of - practical knowledge of procedureprocedure

- preshyopic age group- preshyopic age group

Patient selection CriteriaPatient selection Criteria

1)1) Above 18 years of ageAbove 18 years of age2)2) Stable refraction for atleast for one yearStable refraction for atleast for one year3)3) Refusal to use glass or Contact Lens Refusal to use glass or Contact Lens 4)4) Contact lens intoleranceContact lens intolerance5)5) Absence of corneal pathologyAbsence of corneal pathology6)6) Realistic expectation from the procedureRealistic expectation from the procedure7)7) Properly obtained informed consentProperly obtained informed consent

HistoryHistory

Stability of RefractionStability of Refraction

- stable atleast for preceding year- stable atleast for preceding year

- 18 years or Older- 18 years or Older

- change in spherical equivalent - change in spherical equivalent should not be more than 0.50D should not be more than 0.50D over over 12 months12 months

Contact LensContact Lens

- Reversible changes in refractive - Reversible changes in refractive status of eyestatus of eye

- Discontinue CL atleast 2 weeks - Discontinue CL atleast 2 weeks in soft lens & 4 weeks in RGP / hard in soft lens & 4 weeks in RGP / hard lens users. lens users.

Clinical ExaminationClinical Examination

•Uncorrected and best corrected visual acuityUncorrected and best corrected visual acuity•Manifest and cycloplegic refraction Manifest and cycloplegic refraction •Fundus examinationFundus examination•Slit lamp examinationSlit lamp examination•Keratometry and axial lengthKeratometry and axial length•Corneal topographyCorneal topography•PachymetryPachymetry•Pupil sizePupil size•IOPIOP•Specular microscopySpecular microscopy•Glare & contrast sensitivityGlare & contrast sensitivity

InstrumentsInstruments

(1)(1) Laser machine Laser machine

(2)(2) Eye tracking systemEye tracking system

(3)(3) Foot switchesFoot switches

(4)(4) Micro keratomeMicro keratome

(5)(5) Power supplyPower supply

(6)(6) New bladeNew blade

(7)(7) Suction ringSuction ring

Patient PreparationPatient Preparation

Some surgeons prefer to sedateSome surgeons prefer to sedateEye cleaned with 5 % povidone iodine solutionEye cleaned with 5 % povidone iodine solutionBroad spectrum antibioticBroad spectrum antibioticPatient, head must be parallel to floor and the Patient, head must be parallel to floor and the chin & forehead should be at the same levelchin & forehead should be at the same levelPatient cornea is perpendicular to laser beamPatient cornea is perpendicular to laser beamTopical anaesthesia drops applied 10 minutes Topical anaesthesia drops applied 10 minutes prior to surgery and just before inserting prior to surgery and just before inserting speculumspeculumEye Drape.Eye Drape.

Post operative managementPost operative management

•SIL after an hourSIL after an hour

•Steroids for 1 weekSteroids for 1 week

•Tear supplementsTear supplements

ConclusionConclusion

Complications following Lasik though Complications following Lasik though rare can be sight threatening rare can be sight threatening

- Demand for safetyDemand for safety- Knowledge experience careful use Knowledge experience careful use

and maintanence of microkerotome and maintanence of microkerotome can reduce incidence of these can reduce incidence of these complicationscomplications