LASIK DEMYSTIFIEDPRK REVISITED

INDOREDRISHTI.WORDPRESS.COM

DR DINESH MITTAL DR SONALEE MITTAL

DRISHTI EYE HOSP VIJAYNAGAR INDORE

Eye’s refractive power determined by 1. Power of the cornea 2. Power of the lens 3. Length of the eye

EMMETROPIA - IMAGE OF THE OBJECT BEING VIEWED IS FOCUSED ON RETINA

1. Myopia - Near-

sightedness- Image is focused

in front of retina2. Hyperopia - Far-sightedness- Image is focused

behind retina

LASIK (Laser-assisted in situ keratomileusis)

•Most commonly performed refractive surgery• Excimer laser ablation of corneal stroma beneath a hinged corneal flap created with a mechanical microkeratome / femtosecond laser

LASIK STEPS

TOPICAL ANAESTHESIA

SUCTION RING

MICROKERATOME HEAD

EXCIMER LASER FLAPFLAP PUT BACK

NEW CURVATURE

LASIK

ADVANCED SURFACE ABLATIONS

REMOVAL OF EPITHELIUMSPATULA

⓴% ALCHOL

ROTARY BRUSH

MUNNERLYN FORMULA

PERCENT TISSUE ALTERED PTA

PTA SHOULD BE LESS THAN 40 %

COMPLICATIONCOMPLICATION LASIK ASAECTASIA ***** *

FLAP RELATED ***** NO

HAZE * ***

DRY EYE ** *INFECTIONS * **INFLAMMATORY *** *IRREGULAR ASTIGMATISM

* *

WHICH PROCEDURE

WHICH PROCEDURE

SCREENINGALGORITHM

Refractive surgery trends

lasik

lasik

PREOP TESTING

EVALUATION

INDICATIONS

EXAMINATION

EQUIPMENT

TOPOGRAPHIC ANALYSIS Keratometry & Computerized Videokeratography

PACHYMETRY measuring thickness of cornea

ULTRASONIC PACHYMETRYMinimum bed

thickness (275µ)

TOP ❿ RED FLAGS

screening

consultation

OCULAR DISEASE

Visually demanding occupations

Inappropriate expectations

All corneal refractive surgical procedures reduce corneal strength to varying degrees

Excessive corneal weakening can result in nonprogressive irregular astigmatism or progressive corneal ectasia

ECTASIA RISK SCORE SYSTEM

TO BE CONTINUED IN PART 2

LASIK DEMYSTIFIEDPRK REVISITED

INDOREDRISHTI.WORDPRESS.COMPART 2

DR DINESH MITTAL DR SONALEE MITTAL

DRISHTI EYE HOSP VIJAYNAGAR INDORE

TOMOGRAPHY

THANKS TO MAZEN M SINZAB

TOMOGRAPHY• ANTERIOR CURVATURE ( TOPOGRAPHY )• ANT. & POST. CORNEAL

SURFACE ELEVATION DATA• REGIONAL CORNEAL

THICKNESS• BELIN / AMBROSIO DISPLAY FOR

EARLY DETECTION OF ECTASIA

PENTACAM GOLD STANDARD GIVE ALL ABOVE DATA

Topography pattern categories

pentacam

BFS>8 ANT ; >18 POST

DECISION

PRK

NO RISK DO PRK OR LASIK

K READINGS

K READINGS

K READINGS

K READINGS

K READINGS

K READINGS

K READINGS

K READINGS effect on flap properties

TO BE CONTINUED IN PART 3

LASIK DEMYSTIFIEDPRK REVISITED

INDOREDRISHTI.WORDPRESS.COMPART 3

DR DINESH MITTAL DR SONALEE MITTAL

DRISHTI EYE HOSP VIJAYNAGAR INDORE

THANK YOUDR DINESHDR SONALEE