Custom Flap Formation: Custom Flap Formation: Advantages of Elliptical FlapsAdvantages of Elliptical Flaps

for LASIK Patientsfor LASIK Patients

Henry Perry MDHenry Perry MD11, Eric Donnenfeld MD, Eric Donnenfeld MD11,,& Kerry Solomon, MD& Kerry Solomon, MD22

11Ophthalmic Consultants of Long Island, Rockville Centre, NYOphthalmic Consultants of Long Island, Rockville Centre, NY 22Ophthalmology, Medical University of South Carolina, Charleston, SCOphthalmology, Medical University of South Carolina, Charleston, SC

Drs. Donnenfeld and Solomon are Consultants with AMO

Ophthalmic Consultants of Long IslandOphthalmic Consultants of Long Island

Surgical Techniques to ReduceSurgical Techniques to ReduceDry Eye Following LASIKDry Eye Following LASIK

Small flaps with large Small flaps with large hinges reduce the risk hinges reduce the risk of post-operative dry of post-operative dry eye.eye.1,21,2

Thin planar flaps result Thin planar flaps result in less post-operative in less post-operative dry eye disease.dry eye disease.33

1 1 Donnenfeld, ED, Solomon, K, Perry HD, et al. The Effect of Hinge Position on Corneal Sensation Donnenfeld, ED, Solomon, K, Perry HD, et al. The Effect of Hinge Position on Corneal Sensation and Dry Eye Following LASIK. and Dry Eye Following LASIK. OphthalmologyOphthalmology 2003. 2003.22 Donnenfeld ED, Ehrenhaus M, Solomon R, et al. The Effect of Hinge Width on Corneal Sensation Donnenfeld ED, Ehrenhaus M, Solomon R, et al. The Effect of Hinge Width on Corneal Sensation and Dry Eye Following LASIK. and Dry Eye Following LASIK. JCRSJCRS 2004 200433 Durrie ASCRS 2007 Durrie ASCRS 2007

New IntraLase TechnologyNew IntraLase Technology 5 5thth Generation Femtosecond Laser Generation Femtosecond Laser Inverted Bevel-In Side Cut Angle:Inverted Bevel-In Side Cut Angle:

Provides better wound healing.Provides better wound healing.1,21,2

Increased flap adhesion post-operativelyIncreased flap adhesion post-operatively 3x more flap stability for iFS laser (150° side 3x more flap stability for iFS laser (150° side

cut) vs microkeratome during flap lift.cut) vs microkeratome during flap lift.22 Significantly reduced flap gutter improves nerve Significantly reduced flap gutter improves nerve

apposition.apposition.33

Ophthalmic Consultants of Long IslandOphthalmic Consultants of Long Island

1Prof J Marshall. Presented ASCRS 2008.2Prof M Knorz. Presented ASCRS 2008.3P Binder MD & A Chayet MD. Presented

ASCRS 2008.

New IntraLase Technology New IntraLase Technology 5 5thth Generation Femtosecond Laser Generation Femtosecond Laser

Elliptical Flap Option:Elliptical Flap Option: Moves the hinge peripherally for maximum stromal Moves the hinge peripherally for maximum stromal

bed exposure and full delivery of excimer ablation.bed exposure and full delivery of excimer ablation. Allows use of wider hinge angle for greater flap Allows use of wider hinge angle for greater flap

stability and improved preservation of corneal stability and improved preservation of corneal nerves.nerves.

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Ablation ZoneFlap

Study: Purpose To evaluate the effect of an elliptical flap

with reverse side cut on corneal sensation after LASIK.

Study: MethodsStudy: Methods Prospective open label trial.Prospective open label trial. 150 kHZ femtosecond flaps.150 kHZ femtosecond flaps. 20 eyes of 10 consecutive patients who underwent bilateral 20 eyes of 10 consecutive patients who underwent bilateral

simultaneous LASIK using elliptical/reverse side cut flaps simultaneous LASIK using elliptical/reverse side cut flaps (150(150oo) & 4mm hinges ) & 4mm hinges were compared to were compared to 20 eyes of 10 20 eyes of 10 consecutive patients who underwent bilateral simultaneous consecutive patients who underwent bilateral simultaneous LASIK using round flaps with 70LASIK using round flaps with 70oo flaps & 3mm hinges. flaps & 3mm hinges.

All procedures with VISXS4 Excimer laser custom All procedures with VISXS4 Excimer laser custom treatment for myopia.treatment for myopia.

All nasal hinge flaps 110 microns.All nasal hinge flaps 110 microns. All flaps 8.5 mm diameter.All flaps 8.5 mm diameter.

Study: Methods Pre-operative baseline visual acuity and

Cochet-Bonnet esthesiometry. Patients seen 1 day, 1 week, 1 month, & 3

months after procedure. Visual acuity measured at 1 day & 1 week

visits. All tests repeated at all subsequent visits.

Mean Corneal Sensation Elliptical Flap with Reverse Side Cut

vs. Conventional Round

0

1

2

3

4

5

6

Mea

n C

orne

al S

ensa

tion

(cm

)

Preop 1 wk 1 mo 3 mo

Elip/RSC Conventional

P>0.05

DiscussionDiscussion Elliptical flaps allow customization of flaps to fit Elliptical flaps allow customization of flaps to fit

the patient. the patient. Elliptical flap shapes prevent resection of the Elliptical flap shapes prevent resection of the

vital peripheral corneal fibers, moves the hinge vital peripheral corneal fibers, moves the hinge peripherally to maximize stromal bed exposure peripherally to maximize stromal bed exposure for full delivery of excimer laser ablation, and for full delivery of excimer laser ablation, and allows use of wider hinge for greater flap allows use of wider hinge for greater flap stability and preservation of corneal nerves. stability and preservation of corneal nerves.

Reverse side cut improves flap stability and Reverse side cut improves flap stability and severed nerve apposition which improves severed nerve apposition which improves corneal sensation and reduces dry eye.corneal sensation and reduces dry eye.

ConclusionConclusion The latest generation femtosecond laser The latest generation femtosecond laser

appears to offer clinical advantages, not only appears to offer clinical advantages, not only for custom flap creation in unusual eyes, but for custom flap creation in unusual eyes, but also for improving flap architecture, stability also for improving flap architecture, stability and corneal sensation in routine cases.and corneal sensation in routine cases.

A larger, masked controlled trial is necessary A larger, masked controlled trial is necessary to establish clinical significance. to establish clinical significance.

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Summary: Surgical Techniques to Summary: Surgical Techniques to Reduce Dry Eye Following LASIKReduce Dry Eye Following LASIK Small elliptical flaps with large hinges reduce Small elliptical flaps with large hinges reduce

the risk of post-operative dry eyethe risk of post-operative dry eye Customize the flap to the ablation.Customize the flap to the ablation.

Thin planar flaps.Thin planar flaps. Bevel-in side cut to improve corneal nerve Bevel-in side cut to improve corneal nerve

apposition.apposition.