REFRACTIVE SURGERYREFRACTIVE SURGERY

Capt dr shoaib MuhammadCapt dr shoaib Muhammad

INTRODUCTIONINTRODUCTION

• A RANGE OF PROCEDURES AIMED A RANGE OF PROCEDURES AIMED AT CHANGING REFRACTION OF THE AT CHANGING REFRACTION OF THE EYE BY ALTERING THE CORNEA EYE BY ALTERING THE CORNEA AND / OR CRYSTALLINE LENSAND / OR CRYSTALLINE LENS

• REFRACTIVE ERRORS CORRECTED REFRACTIVE ERRORS CORRECTED INCLUDE MYOPIA, INCLUDE MYOPIA, HYPERMETROPIA AND HYPERMETROPIA AND ASTIGMATISMASTIGMATISM

CORRECTION OF MYOPIACORRECTION OF MYOPIA

• CORNEAL SURGERYCORNEAL SURGERY– RADIAL KERATOTOMYRADIAL KERATOTOMY

•RADIAL INCISIONS IN PERIPHERAL CORNEARADIAL INCISIONS IN PERIPHERAL CORNEA

– PHOTOREFRACTIVE KERATECTOMYPHOTOREFRACTIVE KERATECTOMY– LASER-IN-SITU KERATOMILEUSIS LASER-IN-SITU KERATOMILEUSIS

(LASIK)(LASIK)– INTRASTROMAL PLASTIC RINGSINTRASTROMAL PLASTIC RINGS

•CAUSE CENTRAL CORNEAL FLATTENINGCAUSE CENTRAL CORNEAL FLATTENING

• LENS SURGERYLENS SURGERY– CLEAR LENS EXTRACTIONCLEAR LENS EXTRACTION– PHAKIC POSTERIOR CHAMBER PHAKIC POSTERIOR CHAMBER

INTRAOCULAR LENS IMPLANTATIONINTRAOCULAR LENS IMPLANTATION– PHAKIC ANTERIOR CHAMBER PHAKIC ANTERIOR CHAMBER

INTRAOCULAR LENS IMPLANTATIONINTRAOCULAR LENS IMPLANTATION

APPEARANCE FOLLOWING APPEARANCE FOLLOWING RADIAL KERATOTOMYRADIAL KERATOTOMY

APPEARANCE FOLLOWING LASER APPEARANCE FOLLOWING LASER THERMAL KERATOPLASTYTHERMAL KERATOPLASTY

CORRECTION OF HYPERMETROPIACORRECTION OF HYPERMETROPIA

• CORNEAL SURGERYCORNEAL SURGERY– PRKPRK

•CAN CORRECT LOW DEGREES OF CAN CORRECT LOW DEGREES OF HYPERMETROPIAHYPERMETROPIA

– LASIKLASIK•CAN CORRECT UPTO 4 DCAN CORRECT UPTO 4 D

– LASER THERMAL KERATOPLASTYLASER THERMAL KERATOPLASTY•HOLMIUM LASERHOLMIUM LASER

• LENS SURGERYLENS SURGERY– PHAKIC INTRAOCULAR LENS PHAKIC INTRAOCULAR LENS

IMPLANTATION AT AN EARLY STAGEIMPLANTATION AT AN EARLY STAGE

CORRECTION OF ASTIGMATISMCORRECTION OF ASTIGMATISM

• CORNEAL SURGERYCORNEAL SURGERY– ARCUATE KERATOTOMYARCUATE KERATOTOMY

• MAY BE COMBINED WITH COMPRESSION MAY BE COMBINED WITH COMPRESSION SUTURE PLACED IN PERPENDICULAR MERIDIANSUTURE PLACED IN PERPENDICULAR MERIDIAN

– PRKPRK• CAN CORRECT UPTO 3 DCAN CORRECT UPTO 3 D

– LASIKLASIK• CAN CORRECT UPTO 5 DCAN CORRECT UPTO 5 D

• LENS SURGERYLENS SURGERY– USING A TORIC INTRAOCULAR LENS USING A TORIC INTRAOCULAR LENS

IMPLANTIMPLANT– POSTOPERATIVE ROTATION OF IMPLANT POSTOPERATIVE ROTATION OF IMPLANT

MAY OCCURMAY OCCUR

PHOTOREFRACTIVE KERATECTOMYPHOTOREFRACTIVE KERATECTOMY

• PERFORMED WITH EXCIMER LASERPERFORMED WITH EXCIMER LASER• MYOPIA TREATED WITH ABLATING THE MYOPIA TREATED WITH ABLATING THE

CENTRAL ANTERIOR CORNEAL SURFACECENTRAL ANTERIOR CORNEAL SURFACE• 10 MICROMETER ABLATION CORRECTS 10 MICROMETER ABLATION CORRECTS

1 D OF MYOPIA1 D OF MYOPIA• CAN CORRECT CAN CORRECT

– MYOPIA UPTO 6 DMYOPIA UPTO 6 D– ASTIGMATISM UPTO 3 DASTIGMATISM UPTO 3 D– LOW HYPERMETROPIALOW HYPERMETROPIA

PRINCIPLES OF PRINCIPLES OF PHOTOREFRACTIVE PHOTOREFRACTIVE KERATECTOMY FOR KERATECTOMY FOR MYOPIAMYOPIA

TECHNIQUE OF PRKTECHNIQUE OF PRK

• VISUAL AXIS MARKEDVISUAL AXIS MARKED

• PATIENT FIXATES AT AIMING PATIENT FIXATES AT AIMING BEAM OF THE LASERBEAM OF THE LASER

• LASER APPLIED TO ABLATE LASER APPLIED TO ABLATE ONLY BOWMAN LAYER AND ONLY BOWMAN LAYER AND ANTERIOR STROMAANTERIOR STROMA

• TAKES USUALLY 30 – 60 TAKES USUALLY 30 – 60 SECONDSSECONDS

APPEARANCE DURING APPEARANCE DURING PRKPRK

COMPLICATIONS OF PRKCOMPLICATIONS OF PRK• SLOW HEALING EPITHILIAL DEFECTSSLOW HEALING EPITHILIAL DEFECTS• CORNEAL HAZECORNEAL HAZE• POOR NIGHT VISIONPOOR NIGHT VISION• REGRESSION OF REFRACTIVE CORRECTIONREGRESSION OF REFRACTIVE CORRECTION

• UNCOMMON PROBLEMS INCLUDEUNCOMMON PROBLEMS INCLUDE– DECENTRED ABLATIONDECENTRED ABLATION– SCARRINGSCARRING– IRREGULAR ASTIGMATISMIRREGULAR ASTIGMATISM– HYPOASTHESIAHYPOASTHESIA– STERILE INFILTRATESSTERILE INFILTRATES– INFECTIONINFECTION– ACUTE CORNEAL NECROSISACUTE CORNEAL NECROSIS

SUBEPITHELIAL CORNEAL SUBEPITHELIAL CORNEAL HAZE FOLLOWING PRKHAZE FOLLOWING PRK

Excimer Laser Epithelial Excimer Laser Epithelial Keratomileusis(LASEK)Keratomileusis(LASEK)

Corneal epithelium is loosened and set Corneal epithelium is loosened and set aside, or removed, refractive procedure is aside, or removed, refractive procedure is performed with the excimer laser (PRK), performed with the excimer laser (PRK), Finally epithelial layer is brought back to Finally epithelial layer is brought back to recover the cornea again and held in placerecover the cornea again and held in place

IndicationsIndicationsMyopia up to – 6.0 dioptersMyopia up to – 6.0 dioptersHypermetropia up to + 3.0 dioptersHypermetropia up to + 3.0 dioptersAstigmatism up to 3.0 dioptersAstigmatism up to 3.0 diopters

AdvantageAdvantageLess glare problem than PRKLess glare problem than PRK

LASER IN-SITU LASER IN-SITU KERATOMILEUSISKERATOMILEUSIS

• CURRENTLY MOST FREQUENTLY CURRENTLY MOST FREQUENTLY PERFORMED REFRACTIVE PROCEDUREPERFORMED REFRACTIVE PROCEDURE

• CAN CORRECT CAN CORRECT – HYPERMETROPIA OF UPTO 4 DHYPERMETROPIA OF UPTO 4 D– ASTIGMATISM UPTO 5 DASTIGMATISM UPTO 5 D– MYOPIA OF UPTO 12 DMYOPIA OF UPTO 12 D

• TO PREVENT CORNEAL ECTASIA, A RESIDUAL TO PREVENT CORNEAL ECTASIA, A RESIDUAL CORNEAL BASE OF 250 MICROMETER CORNEAL BASE OF 250 MICROMETER THICKNESS MUST REMAIN AFTER THE FLAP THICKNESS MUST REMAIN AFTER THE FLAP HAS BEEN CUT AND TISSUE ABLATEDHAS BEEN CUT AND TISSUE ABLATED

CORNEAL FLAP CREATED CORNEAL FLAP CREATED WITH A KERATOME DURING WITH A KERATOME DURING

LASIKLASIK

COMPLICATIONS OF LASIKCOMPLICATIONS OF LASIK

• OPERATIVE FLAP-RELATEDOPERATIVE FLAP-RELATED– BUTTONHOLESBUTTONHOLES– THIN FLAPSTHIN FLAPS– FLAP AMPUTATIONFLAP AMPUTATION– INCOMPLETE OR IRREGULAR FLAPINCOMPLETE OR IRREGULAR FLAP– RARELY CORNEAL PERFORATIONRARELY CORNEAL PERFORATION

• POSTOPERATIVEPOSTOPERATIVE– WRINKLING, DISTORTION OR DISLOCATION OF WRINKLING, DISTORTION OR DISLOCATION OF

FLAPFLAP– EPITHELIAL INGROWTH UNDER THE FLAPEPITHELIAL INGROWTH UNDER THE FLAP– DIFFUSE LAMELLAR KERATITISDIFFUSE LAMELLAR KERATITIS– PERIPHERAL CORNEAL INFILTRATESPERIPHERAL CORNEAL INFILTRATES

WRINKLED FLAP FOLLOWING WRINKLED FLAP FOLLOWING LASIKLASIK

PRK vs. LASIKPRK vs. LASIK Same destination; Different Same destination; Different

journeyjourney PRKPRK

Day one: Day one: “Oowww!”“Oowww!”

Less surgical riskLess surgical risk Slower recoverySlower recovery 80% 20/2080% 20/20 HazeHaze No flapNo flap 0.2 – 0.3% risk 0.2 – 0.3% risk

visual loss (>2 visual loss (>2 lines)lines)

LASIKLASIK

Day one: Day one: “Wow!”“Wow!”

Greater surgical Greater surgical riskrisk

Quicker recoveryQuicker recovery 80% 20/2080% 20/20 No hazeNo haze FlapFlap 0.2 – 0.3% risk 0.2 – 0.3% risk

visual loss (>2 visual loss (>2 lines)lines)

THANK YOUTHANK YOU