Augenabteilung am St. Franziskus Hospital Münster

The Role of the Epithelial Flap

in EPI-LASIK and LASEK

Suphi TaneriTravel Grant from B&L

ASCRS Symposium, April 2-8, 2009, San FranciscoASCRS Symposium, April 2-8, 2009, San Francisco

Augenabteilung am St. Franziskus Hospital MünsterAugenabteilung am St. Franziskus Hospital Münster

PurposePurpose• To evaluate the safety and predictability of

EPI-LASIK using an EPI Separator head coupled to the Zyoptix XP microkeratome

• To elucidate the influence of the epithelial flap in EPI-LASIK and LASEK on visual recovery and pain perception.

Augenabteilung am St. Franziskus Hospital MünsterAugenabteilung am St. Franziskus Hospital Münster

MethodsMethods• Ongoing prospective single-center study

comparing 14 eyes of 7 patients treated with EPI-LASIK using the XP EPI Separator (Bausch & Lomb, Rochester, New York) to a control group of 14 eyes of 7 patients treated with LASEK.

• Each epithelial flap was clinically evaluated by its dimensions and completeness of epithelial separation.

• After laser ablation, epithelial flaps of one eye per patient were repositioned and the other one discarded. All eyes received a soft contact lens.

Augenabteilung am St. Franziskus Hospital MünsterAugenabteilung am St. Franziskus Hospital Münster

MethodsMethodsBaseline:

EPI-LASIK

Age (Years)

Corneal Thickness (µm)

Sphere (D)

Cylinder (D)

SE (D) BCVA

average Keratometry(D)

Mean 29 550 -3.81 -0.67 -4.14 0.93 43.9SD 5 46 1.50 0.48 1.58 0.10 0.8Min 20 497 -1.50 -1.50 -6.63 0.7 42.6Max 40 611 -6.25 0.0 -1.63 1.0 45.9

LASEKAge (Years)

Corneal Thicknes (µm)

Sphere (D)

Cylinder (D)

SE (D) BCVA

average Keratometry (D)

Mean 34 530 -3.61 -0.43 -3.82 0.9 44.3

SD 4 25 1.42 0.44 1.57 0.13 1.7

Min 20 494 -1.75 -1.50 -5.88 0.7 41.6

Max 50 588 -5.75 -0.25 -2.0 1.0 47.0

Augenabteilung am St. Franziskus Hospital MünsterAugenabteilung am St. Franziskus Hospital Münster

ResultsResultsHE stain of a discarded epithelial flap

magnification 200x

Microscopical examination showed complete epithelial separation

Augenabteilung am St. Franziskus Hospital MünsterAugenabteilung am St. Franziskus Hospital Münster

ResultsResultsPAS stain of a discarded epithelial flapmagnification 200x

Microscopical examination showed complete epithelial separation

Augenabteilung am St. Franziskus Hospital MünsterAugenabteilung am St. Franziskus Hospital Münster

Results: Visual recoveryResults: Visual recovery

Mean uncorrected visual acuity was slightly better in LASEK in the abscene of an epithelial flap.In Epi-LASIK mean uncorrected visual acuity was better if the flap had been repositioned (not significant).

Augenabteilung am St. Franziskus Hospital MünsterAugenabteilung am St. Franziskus Hospital Münster

Results: Development of pain perceptionResults: Development of pain perception

Pain scores decreased continually from day 1 to day 4 in all groups and showed no significant difference between the 4 groups.

Augenabteilung am St. Franziskus Hospital MünsterAugenabteilung am St. Franziskus Hospital Münster

Results: Closing of the epitheliumResults: Closing of the epithelium

closed

Augenabteilung am St. Franziskus Hospital MünsterAugenabteilung am St. Franziskus Hospital Münster

Results: Haze and Epithelial Results: Haze and Epithelial OpacificationOpacification

• Epithelial opacification was slightly higher with repositioned flaps (Fantes scale).

LASEK Mean RangeFlap repositioned 0.43 ± 0.53 0-1Flap discarded 0.33 ± 0.52 0-1Epi-LASIKFlap repositioned 0.75 ± 0.27 0.5-1.0Flap discarded 0.33 ± 0.41 0-1.0

Augenabteilung am St. Franziskus Hospital MünsterAugenabteilung am St. Franziskus Hospital Münster

ConclusionConclusionInitial results indicate a safe and standardized fashion of performing a surface ablation using the Zyoptix XP Epi Separator.

The role of the epithelial flap in surface ablation seems negligible in the first 3 months.

Differences in late on-set haze formation may exist.