Correction of PresbyopiaCorrection of Presbyopia with Kera with Kera No-touch No-touch

techniquetechnique

Department of OphthalmologyDepartment of Ophthalmology

Chung-Ang UniversityChung-Ang University

Jae Chan Kim M.D., Ph.D.,

Refractive regression : major challenge after refractive surgery

Refractive regression : major challenge after refractive surgery

Why?Why?

Inconsistensy of wound healing after refractive surgery

Refractive regression process predominate in regions of greater tissue removal

(William J Dupps Jr, etc. Experimental eye research 2006)

Disruption of epithelium over central cornea in PRK amplifies the wound healing response and accounts for higher rates of regression and haze

(R.R Mohan, etc. Exp. Eye 2003)

Why?Why?

Inconsistensy of wound healing after refractive surgery

Refractive regression process predominate in regions of greater tissue removal

(William J Dupps Jr, etc. Experimental eye research 2006)

Disruption of epithelium over central cornea in PRK amplifies the wound healing response and accounts for higher rates of regression and haze

(R.R Mohan, etc. Exp. Eye 2003)

Refractive regression : major challenge after refractive surgeryRefractive regression : major challenge after refractive surgery

Enhanced early wound healing improves final visual outcome Enhanced early wound healing improves final visual outcome

by inhibition of regression?by inhibition of regression?

Refractive regression : major challenge after refractive surgeryRefractive regression : major challenge after refractive surgery

Enhanced early wound healing improves final visual outcome Enhanced early wound healing improves final visual outcome

by inhibition of regression?by inhibition of regression?

Preservation of central corneal epithelium Preservation of central corneal epithelium in corneal ablation surgery in corneal ablation surgery

lead to lead to

shortening of early wound healing timeshortening of early wound healing time

decrease of refractive regressiondecrease of refractive regression

Concept :

No-touch surgery in presbyopia No-touch surgery in presbyopia ??

Object: emmetropia c mild hyperopiaObject: emmetropia c mild hyperopia

effective corneal ablationeffective corneal ablation

& more accurate treatments& more accurate treatments

* Dual flying spot* Dual flying spot

homogenous energy delivery

Inventor : George huang Ph.D.

Idea from Jae Chan Kim M.D.

Woo chan Park M.D., Byung moo Min M.D.

* Small beam size :0.44mm* Small beam size :0.44mm& Random projection& Random projection

delicate ablationdelicate ablation

* Smooth ablation c no ridge* Smooth ablation c no ridge

Corneal ablation methodCorneal ablation method& Concept of early wound healing& Concept of early wound healing

Corneal ablation methodCorneal ablation method& Concept of early wound healing& Concept of early wound healing

<Emmetropia<Emmetropia –– Ablation of zone 2 only> Ablation of zone 2 only><Emmetropia<Emmetropia –– Ablation of zone 2 only> Ablation of zone 2 only>•CentCenterer - Distance vision- Distance vision

: Spherical curvature: Spherical curvature

No-touch zone(3.5~4.2mm)No-touch zone(3.5~4.2mm)

•Paracentral& PeripheralParacentral& Peripheral

- Near Vision- Near Vision

: Aspherical curvature: Aspherical curvatureDoughnut shape

1.Far 2.

Near

Ablation zone

Epithelial migrationEpithelial migration

than Peripheral epitheliumthan Peripheral epithelium

Bidirectional wound healingBidirectional wound healing

Central epithelium ; more fasterCentral epithelium ; more faster

Materials & MeasurementsMaterials & Measurements

10 patients, 12 eyes 10 patients, 12 eyes M:F = 6 : 4, 51.2 years old (43-60)M:F = 6 : 4, 51.2 years old (43-60) Emmetropia c mild hyperopia(SE ≤ ±1.25D) Emmetropia c mild hyperopia(SE ≤ ±1.25D) - mean S.E. : 0.78D- mean S.E. : 0.78D

December, 2007~ June,2008 December, 2007~ June,2008

F/U: postoperative 1, 4, 30days F/U: postoperative 1, 4, 30days MeasurementsMeasurements - - Far and near uncorrected visual acuity Far and near uncorrected visual acuity

- DOF, depth of focus- DOF, depth of focus - Topography (Humphrey® ATLAS™, Zeiss) - Topography (Humphrey® ATLAS™, Zeiss) - Aberrometer (WASCA aberrometer, Zeiss)- Aberrometer (WASCA aberrometer, Zeiss) - Contrast sensitivity (CSV-1000E, Vector vision)- Contrast sensitivity (CSV-1000E, Vector vision) - Rate of corneal wound healing - Rate of corneal wound healing

Result: Corneal epithelial wound healing rateResult: Corneal epithelial wound healing rate

Total ablationTotal ablationS.E 0.75S.E 0.75

Ablation depth 39MmAblation depth 39Mm

No-touchNo-touch

S.E 0.5S.E 0.5

Ablation depth 35MmAblation depth 35Mm

Postop.

Postop. Postop.15hrs

Postop.15hrs

POD#4

POD#4

Postop.15hrs POD#4Postop.

0

1

2

3

4

5

MEL80 no-touch

4.5days4.5days

1.3days1.3days

Comparison of corneal epithelial wound healing daysComparison of corneal epithelial wound healing days

wound healing dayswound healing days

Significant at P<0.05 at t-testSignificant at P<0.05 at t-test

*

Result: IsoBeam D200 No-touch zone (3.7~4.2mm) comparison of MEL80

Result: IsoBeam D200 No-touch zone (3.7~4.2mm) comparison of MEL80

00.20.40.60.8

11.21.4

Preop

POD#1

POD#2

POD#4

POD#3

0 .. ..

POD1Y

UCNVA(no touch) UCNVA(MEL 80)

Central zone : 3.7~4.2mm Central zone : 3.7~4.2mm

5Pts. (6eyes)5Pts. (6eyes)

emmetropia (mean S.E: 0.72)emmetropia (mean S.E: 0.72)

5.2days

?2.4days

0

0.2

0.4

0.6

0.8

1

Preop

POD#1

POD#2

POD#4

POD#3

0 .. ..

POD1Y

DUCVA(no touch) DUCVA(MEL 80)

Near visionFar vision -0.2 - 0.1

0.0

+ 0.1

+ 0.2

+ 0.4

+ 0.7

+ 1

Log MAR

?1.2days

2.3days0.5

SummarySummary

Wound healing days by IsoBeam No-touch technique was significantly more faster than that by MEL-80

Effective near & far vision by IsoBeam was significantly more faster achieved by preserving of central cornea epithelium than that by MEL-80

Expect to good final visual outcome due to faster epithelial wound healing time by preserving central cornea epithelium

Wound healing days by IsoBeam No-touch technique was significantly more faster than that by MEL-80

Effective near & far vision by IsoBeam was significantly more faster achieved by preserving of central cornea epithelium than that by MEL-80

Expect to good final visual outcome due to faster epithelial wound healing time by preserving central cornea epithelium

Reduction of corneal ablation area & preservation of central corneal epithelium Bidirectional wound healing shortening of early wound healing days decrease of refractive regression

Reduction of corneal ablation area & preservation of central corneal epithelium Bidirectional wound healing shortening of early wound healing days decrease of refractive regression

Modulation of final visual outcome by early wound healing

Modulation of final visual outcome by early wound healing