Evaluation of Efficacy of Evaluation of Efficacy of LASEK Refractive Surgical LASEK Refractive Surgical Procedure vs. Epi-Lasik in Procedure vs. Epi-Lasik in

terms of patient comfort and terms of patient comfort and speed of recoveryspeed of recovery

Authors: Authors: Roshan Givergis, BARoshan Givergis, BAXiao Jing Wang, BAXiao Jing Wang, BA

Peyman Younesi, MDPeyman Younesi, MDEmil W. Chynn, MD Emil W. Chynn, MD

*none of the authors of this study have any financial interests in the content of this *none of the authors of this study have any financial interests in the content of this posterposter

PurposePurpose

The objective of this study is to The objective of this study is to compare the safety and efficacy of compare the safety and efficacy of the surgical procedures LASEK versus the surgical procedures LASEK versus Epi-LASIK as evaluated in the fields Epi-LASIK as evaluated in the fields of Visual Acuity and Self-assessed of Visual Acuity and Self-assessed pain, blurriness, and dry eye. pain, blurriness, and dry eye.

MaterialsMaterials• Epikeratome: Epikeratome:

Norwood EyeCare Norwood EyeCare Epikeratome Epikeratome System System

• LASER- VISX S4 IR LASER- VISX S4 IR Excimer LaserExcimer Laser

Epi-LASIKEpi-LASIK

• Utilizes a high speed, Utilizes a high speed, oscillating blunt PMMA oscillating blunt PMMA separator to create an separator to create an epithelial sheet at the epithelial sheet at the natural cleavage plane natural cleavage plane - beneath basement - beneath basement membrane and above membrane and above Bowman's layer Bowman's layer

• Unlike other LVC Unlike other LVC techniques, the techniques, the elimination of alcohol and elimination of alcohol and minimized use of minimized use of Mitomycin C (MMC) during Mitomycin C (MMC) during Epi-LASIK maximize overall Epi-LASIK maximize overall corneal cell viability. This corneal cell viability. This coupled with the existence coupled with the existence of an intact, living of an intact, living bandage, enhance patient bandage, enhance patient outcomes and minimizes outcomes and minimizes post-operative haze and post-operative haze and regression.regression.

Histology of Epi-LASIK Histology of Epi-LASIK patientspatients

Intact Basement Membrane

Arrows (red) indicate the presence of intact

basement membrane within the epithelial

sheet.

Images coutsesy of University of Crete, Heraklion, Crete, Greece

Intact EpitheliumHistological micrograph

shows presence of basement membrane

(arrows). Basal cells (BC) and wing cells (WC) are also present within the

separated epithelial sheet.

Separated Sheet H&E stain of an epithelial sheet remains intact

during and after separation using

the Norwood EyeCare

Epikeratome System

LASEKLASEK

• In LASEK , the epithelium, or outer layer of the In LASEK , the epithelium, or outer layer of the cornea, is cut a fine blade called a trephine. Then cornea, is cut a fine blade called a trephine. Then the surgeon covers the eye with an alcohol solution the surgeon covers the eye with an alcohol solution (perhaps one part alcohol and four parts sterile (perhaps one part alcohol and four parts sterile water) for around 30 seconds. The solution loosens water) for around 30 seconds. The solution loosens the edges of the epithelium.the edges of the epithelium.

• After sponging the alcohol solution from the eye, After sponging the alcohol solution from the eye, the surgeon uses a tiny hoe to lift the edge of the the surgeon uses a tiny hoe to lift the edge of the epithelial flap and gently fold it back out of the way. epithelial flap and gently fold it back out of the way. Then he or she uses an excimer laser to sculpt the Then he or she uses an excimer laser to sculpt the corneal tissue underneath. Afterward, the epithelial corneal tissue underneath. Afterward, the epithelial flap is placed back on the eye with a kind of flap is placed back on the eye with a kind of spatula.spatula.

Patient PopulationPatient Population

• The sample size consists of 10 The sample size consists of 10 refractive surgery patients refractive surgery patients undergoing simultaneous bilateral undergoing simultaneous bilateral surgerysurgery

• Mean age: 32.60Mean age: 32.60++ 10.33 10.33

• Male: Female ratio 3:2Male: Female ratio 3:2

MethodsMethods

• The study design consists of a single centered, single-blind The study design consists of a single centered, single-blind controlled trial comparing surgical methods LASEK and Epi-controlled trial comparing surgical methods LASEK and Epi-Lasik.Lasik.

• The sample size consists of 10 refractive surgery patients The sample size consists of 10 refractive surgery patients undergoing simultaneous bilateral surgery. Subjects are undergoing simultaneous bilateral surgery. Subjects are screened during their full workup approximately 1 week screened during their full workup approximately 1 week before the procedure. Different surgical procedures are before the procedure. Different surgical procedures are assigned to each eye based on a randomized process.assigned to each eye based on a randomized process.

• Preoperative and intraoperative procedure are based upon Preoperative and intraoperative procedure are based upon the established protocols for each surgery and differ for the established protocols for each surgery and differ for each eye.each eye.

• Postoperatively, patients are assessed three times during Postoperatively, patients are assessed three times during their regularly schedule post-ops: one day, one week, one their regularly schedule post-ops: one day, one week, one month. Visual acuity is assessed as a measure of relative month. Visual acuity is assessed as a measure of relative effectiveness of the two procedures. effectiveness of the two procedures.

ResultsResults : Self-Reported : Self-Reported PainPain

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

Pain Score

Day ofSurgery

Post-Op Day1

Post-Op Day2

Post-Op Day3

Post-Op Day4

Post-Op Day5

Post-Op Day6

Post-Op Day7

Assessment Day

Avg. Reported Pain for LASEK and Epi-LASIK

LASEK

Epi-LASEK

• Patient self-reported Patient self-reported pain score from Day of pain score from Day of Surgery to Post-op day Surgery to Post-op day 77

• Post-op Days 1 & 2: Post-op Days 1 & 2: – p< 0.05: p< 0.05: SIGNIFICANTSIGNIFICANT

• Post-op days 3-5: Post-op days 3-5: – p> 0.05: INSIGNIFICANTp> 0.05: INSIGNIFICANT

• Post-op days 6 & 7Post-op days 6 & 7– p<0.05: p<0.05: SIGNIFICANTSIGNIFICANT

Result: Self-Reported Result: Self-Reported BlurringBlurring

0

1

2

3

4

5

6

Blurring Score

Post-Op Day 1 Post-Op Day 2 Post-Op Day 3 Post-Op Day 4 Post-Op Day 5 Post-Op Day 6 Post-Op Day 7

Assessment Day

Avg. Reported Score for Post-Operative Blurring

LASEK

Epi-LASIK

• Patient self-reported blurring score from Patient self-reported blurring score from Day of Surgery to Post-op day 7Day of Surgery to Post-op day 7

• P > 0.05 each day: INSIGNIFICANT P > 0.05 each day: INSIGNIFICANT

Results: Self-Reported Dry EyeResults: Self-Reported Dry Eye

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

Dry Eye Score

Post-Op Day 1 Post-Op Day 2 Post-Op Day 3 Post-Op Day 4 Post-Op Day 5 Post-Op Day 6 Post-Op Day 7Assessment Day

Avg. Reported Score for Dry Eye

LASEK

Epi-LASIK

• Patient self-reported Dry-Eye score from Day of Surgery to Patient self-reported Dry-Eye score from Day of Surgery to Post-op day 7Post-op day 7

• Day 1: p< 0.05 : SIGNIFICANTDay 1: p< 0.05 : SIGNIFICANT• Day 2-7: p> 0.05: INSIGNIFICANT Day 2-7: p> 0.05: INSIGNIFICANT

Results: Visual Acuity Results: Visual Acuity

• Visual Acuity assessed post-operatively at 1-day, Visual Acuity assessed post-operatively at 1-day, 1 week, and 1 month 1 week, and 1 month

• p> 0.05 for each visit assessed: INSIGNIFICANT p> 0.05 for each visit assessed: INSIGNIFICANT

0.37

0.46

0.250.27

0.110.12

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

Visual Acuity (LogMAR)

1 - day 1 - wk 1 - month

Assessment Day

Visual Acuity (LogMAR)

LASEK

Epi-LASIK

DiscussionDiscussion

We are currently still enrolling patients to We are currently still enrolling patients to assess the safety and efficacy of the surgical assess the safety and efficacy of the surgical procedures LASEK versus Epi-LASIK using procedures LASEK versus Epi-LASIK using the Epi-keratome without separators in the the Epi-keratome without separators in the fields of Visual Acuity and Self-assessed fields of Visual Acuity and Self-assessed pain, blurriness, and dry eye. pain, blurriness, and dry eye.

These results will be compared to the efficacy These results will be compared to the efficacy of the use of Epi-keratome with separatorsof the use of Epi-keratome with separators

LimitationsLimitations

- Because this study was not double-blinded, the Because this study was not double-blinded, the validity of the results could be biasedvalidity of the results could be biased

- The results obtained were based on self-assessed The results obtained were based on self-assessed pain, blurriness, and dry eyes. Patients filled out pain, blurriness, and dry eyes. Patients filled out the questionnaire on their own; thus, bias by the the questionnaire on their own; thus, bias by the study coordinators is unlikely as no coordinators study coordinators is unlikely as no coordinators were present at assessment. were present at assessment.

- Subject bias was also eliminated due to the fact Subject bias was also eliminated due to the fact that subjects were not made aware of which that subjects were not made aware of which procedure they were getting in either eye procedure they were getting in either eye

• Although the sample size was small (n=10), the Although the sample size was small (n=10), the data proved significant with a p<0.01 for post-data proved significant with a p<0.01 for post-operative self-reported painoperative self-reported pain

Clinical SignificanceClinical Significance

• Epi-LASIK has shown thus far to have significant values in Epi-LASIK has shown thus far to have significant values in the reported pain scale for surgery day and post operative the reported pain scale for surgery day and post operative day 1. day 1. – This may be due to a cleaner separation of basement membrane This may be due to a cleaner separation of basement membrane

and Bowman's layer, leading to quicker healingand Bowman's layer, leading to quicker healing– This also explains the significance showing less reported dry eye This also explains the significance showing less reported dry eye

in Epi-LASIK eye on Post-op day 1 in Epi-LASIK eye on Post-op day 1 – This can also be explained by lack of alcohol solution, which This can also be explained by lack of alcohol solution, which

contributes to a greater release of cytokines contributes to a greater release of cytokines

• On Surgery Post-op day 6 and 7, LASEK treated eye shows On Surgery Post-op day 6 and 7, LASEK treated eye shows significant values of decreased pain as compared to Epi-significant values of decreased pain as compared to Epi-LASIK. However, the rate of change of the LASEK pain scores LASIK. However, the rate of change of the LASEK pain scores is greater than that of Epi-LASIK pain scores. This data is greater than that of Epi-LASIK pain scores. This data supports our initial claim that Epi-LASIK has a rapid recovery supports our initial claim that Epi-LASIK has a rapid recovery time, where as LASEK pain decrease over a longer period of time, where as LASEK pain decrease over a longer period of time. time.

Thank you!Thank you!

Thank you for Thank you for taking time to taking time to view our poster. view our poster. We hope you We hope you enjoy the rest of enjoy the rest of the conference. the conference.

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