Transcript 90 micron

90, 100 & 110 Micron Flap Using
Small Bubble Femtosecond Laser
Scott M. MacRae MD
Professor of Ophthalmology
Professor of Visual Science
University of Rochester
Dr. MacRae is a paid consultant to
Ziemer
UNIVERSITY OF ROCHESTER
Purpose: Compare Outcomes 90 vs
110 Micron Ziemer LDV Flaps
• 25 Eyes in each group
• Mean SE
– 90 micron group: - 6.3 D Sph. -1.0 D Cyl.
– 110 micron group: -4.2 D Sph. -0.6 D Cyl.
UNIVERSITY OF ROCHESTER
Visual Results: 90 vs 110 Micron
LDV Flaps – 3 Months Postop
• 90 Micron Postop:
–
–
–
–
SE -0.145 D + 0.34 D
Sph. -O.01
Cyl. -0.22D
Mean UCVA -0.02
(20/20)
– Mean BCVA -0.07
(20/16)
– 92% of eyes + 0.5 D of
Plano
• 110 Micron
–
–
–
–
SE -0.15 D + 0.30 D
Sph. -0.05 D
Cyl. -0.20 D
Mean UCVA -0.04
(20/20)
– Mean BCVA -0.09
(20/16)
– 96% of eyes + 0.5 D of
Plano
• 90 & 110 Micron Flaps
obtained similar results
UNIVERSITY OF ROCHESTER
LDV Nomogram
Univ. of Rochester/Ziemer
Keratometry
Readings
White to
White
Ring
Size
Hinge Width
90 µm flap
Hinge Width
100 & 110 µm
flap
Steep K’s >46.5
11.5 &
smaller
9.0m
m
0.5 mm
0.5 mm
Steep K’s >
46.5
11.5 &
larger
9.0
0.5 mm
0.5 mm
44.50 - 46.50
11.5 &
smaller
9.0
0.5
0.5
44.5 - 46.50
11.5 &
larger
9.0
0.5
0.5
Average K’s
42.00- 44.50
11.5 &
smaller
9.0
0.5
0.5
Average K’s
42.00-44.5
11.5 and
larger
9.0
0.5
0.5
Flat K’s
<42.00
11.5 and
smaller
9.0
0.6
0.6
Flat K’s
<42.00
11.5 and
larger
9.5
0.6
0.6
UNIVERSITY
OF ROCHESTER
LDV Optimal Flap Management
• Control hydration – Dry LASIK
• Control flap thickness Ziemer:
– Dry ultrasound flap measurements reduces Standard
Deviation
– LDV 110 µm separating @ 105 + 7.2 µm
– LDV 90 µm separating @ 90.2 + 5.7 µm
– Working at “Five sigma”
• Position flap optimally “as if it never moved”
• 90 micron:
– More delicate, drier – “potato chip
– Hourly prednisolone acetate day of surgery, no
rainbow glare or haze compared to IL
– Stretch flap in “Butterfly Technique”, no microstria
UNIVERSITY OF ROCHESTER
Intraoperative Pachymetry:
Dry Method- Dry Before First
Measurement
UNIVERSITY OF ROCHESTER
Ziemer LDV Smaller Spot Size
“Small Bubble” Strategy
• Less energy concentrated in one
area
– Similar to spreading laser spots out with
femto – reduces thermal energy and
cavitation
•
•
•
•
Cavitation rare
No Transient Light Sensitivity Syndrome
No rainbow glare, haze reactions
No Opaque Bubble Layer
UNIVERSITY OF ROCHESTER
Advantages of Ziemer LDV
Femtosecond Small Spot Strategy
• Thin flap - 90 µm strategy allows
LASIK treatment thin corneas
previously needing PRK
– Minimal or no risk of cavitation,
inflammation, haze, or rainbow glare
• Allows deeper Rx with pockets,
tunnels or deep lamellar RX without
using high energy again reducing
inflammation and corneal edema
UNIVERSITY OF ROCHESTER
90 Micron LDV Femto
• Small bubble technology:
– Makes epithelial breakthrough much
less likely
– Opaque Bubble Layer (OBL) minor issue
with LDV
• Start conservatively and handle like
a EpiLASIK flap
• Patients appreciate avoiding PRK!
UNIVERSITY OF ROCHESTER
New Ziemer LDV 100 Micron
Interspace Shields
• Best of both worlds
• LDV 100 µm separating @ 98 + 9 µm
– My Preferred flap thickness
– Minimizes PRK
– Easy to handle and greater comfort factor than
90 microns.
– Use same settings as 110 microns
– Flaps behave like 110 micron flaps
– Allows transition to 90 microns when needed
with greater confidence
– Still use 90 microns confidently in to optimize
thin flap strategy
UNIVERSITY OF ROCHESTER
Summary 90, 100 & 110 Micron
Flaps with Ziemer LDV
• Outcomes Similar for 90 and 110
microns
• Flap thickness Ziemer LDV:
–
–
–
–
–
LDV 110 µm separating @ 105 + 7.2 µm
LDV 90 µm separating @ 90.2 + 5.7 µm
LDV 100 µm separating @ 96.3 + 9 µm
Working at “Five sigma”
Small Bubble technology allows thinner
flaps while avoiding inflammation
UNIVERSITY OF ROCHESTER