presbyopia treatment for emmetropia by center no touch technique to perform the surgery, and compared Kera IsoBeam D200 and Zeiss MEL80 presbyopia results performance through the wound healing period. presbyopia new method to treat emmetropic presbyopia. no touch on center cornea for emmetropia presbyopia.
Correction of Presbyopia with Kera No-touch technique
Jae Chan Kim M.D., Ph.D.,
Department of Ophthalmology Chung-Ang University
Refractive regression : major challenge after refractive surgeryWhy?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)
Concept :Refractive regression : major challenge after refractive surgeryEnhanced early wound healing improves final visual outcome by inhibition of regression?
Preservation of central corneal epithelium in corneal ablation surgery lead to shortening of early wound healing time decrease of refractive regression
No-touch surgery in presbyopia ?Object: emmetropia c mild hyperopia * Dual flying spothomogenous energy delivery
* Smooth ablation c no ridgeeffective corneal ablation
* Small beam size :0.44mm & Random projection delicate ablation & more accurate treatmentsInventor : George huang Ph.D. Idea from Jae Chan Kim M.D.Woo chan Park M.D., Byung moo Min M.D.
Center - Distance vision : Spherical curvature No-touch zone(3.5~4.2mm) Paracentral& Peripheral - Near VisionDoughnut shape1.Fa r 2. Near
Corneal ablation method & Concept of early wound healing
: Aspherical curvature Epithelial migration
Central epithelium ; more faster than Peripheral epithelium
Bidirectional wound healing
Materials & Measurements 10 patients, 12 eyes M:F = 6 : 4, 51.2 years old (43-60) Emmetropia c mild hyperopia(SE 1.25D) - mean S.E. : 0.78D
December, 2007~ June,2008 F/U: postoperative 1, 4, 30days Measurements - Far and near uncorrected visual acuity- DOF, depth of focus - Topography (Humphrey ATLAS, Zeiss) - Aberrometer (WASCA aberrometer, Zeiss) - Contrast sensitivity (CSV-1000E, Vector vision) - Rate of corneal wound healing
Result: Corneal epithelial wound healing ratePostop. Postop.15hrs POD#4
Total ablationS.E 0.75 Ablation depth 39Mm
No-touchS.E 0.5 Ablation depth 35Mm
Comparison of corneal epithelial wound healing days*wound healing days5 4 3 2 1 0MEL80
Significant at P