This document summarizes a study evaluating the effect of simultaneous Keraring implantation using OCT-guided femtosecond laser and corneal crosslinking (CXL) for the treatment of keratectasia. Ten eyes of 9 patients underwent Keraring implantation using an OCT-guided femtosecond laser to create the tunnel, followed by CXL. At 3 months post-op, uncorrected and corrected visual acuity, cylinder, K-values, and corneal HOAs were significantly improved, while endothelial cell density and central corneal thickness were not significantly changed. Corneal topography also improved. The study concluded that simultaneous Keraring implantation using OCT-guided femtosecond laser and CXL was effective for treating keratectasia.

1. Shinagawa LASIK Center
Medical Director, Shinagawa LASIK Center, Tokyo, Japan
Adjunct Professor, Department of Ophthalmology, Wenzhou Medical College, Wenzhou, China
Financial
Disclosure
Dr.
Tomita
is
a
consultant
for
SCHWIND
Eye-­‐Tech-­‐Solu<ons,
Ziemer
Ophthalmic
Systems
AG,
and
AcuFocus
Inc.

2. 1,149,036
Femto
LASIK
cases
since
being
established
in
2004.
Shinagawa
LASIK
Center
in
Tokyo
with
5
branch
clinics.
We
have
a
total
of
131
doctors.
Our
clinics
perform
approx.
70%
of
the
LASIK
procedures
in
Japan.

3. FEMTO
LDV™,
Crystal
Line
&
Z6
(9
units)
(Ziemer,
Switzerland)
AMARIS
(SCHWIND,
Germany)
14
Units
Refrac+ve
Suite
(Alcon,
US)
IntraLase™
FS60
&
iFS
(AMO,
USA)
ALLEGRETTO
Wave®
Eye-­‐Q
(Alcon,
USA)
Visx
star
S4
IR™
19
Units
(AMO,
USA)
1
Unit
23
Units
KXL
System™,
(Avedro,
USA)
11
Units
Other
procedures
also
available:
●
●
●
●
●
Surface
abla+on
(PRK,
LASEK,
EpiLASIK)
Intrastromal
corneal
ring
segments
Phakic
IOLs
● Mul+-­‐focal
IOLs
KAMRA™
Intracorneal
Inlays
CK
(Conduc+ve
Keratoplasty)
3
Units
9 Units

4. ✔
Correcting various degrees of myopia and astigmatism
Keraring offers variable sizes in order to match every patient’s needs
✔
Can be mixed with other refractive surgeries
Keraring implantation is effectively combined with Crosslinking/Intraocular lens/
Photorefractive keratectomy (PRK) in order to achieve maximum effect.
and/or
Keraring
Crosslinking
and/or
Intraocular lens
PRK

5. Intracorneal ring implantation operated at Shinagawa LASIK center
between 2006 and August 2013
Intacs
14%
“
Keraring
86%
ü Keraring’s efficacy even for severe keratectasia/keratoconus makes it our
doctors’ choice.

7. Intracorneal inlay implantation is an effective surgery in order to treat keratoconus
and keratectasia.
Corneal Crosslinking (CXL) is reportedly effective in preventing progression of
keratoconus and keratectasia.
In this study, simultaneous Keraring implantation using OCT-guided femtosecond
laser and Crosslinking was performed and its effect was evaluated.
Keraring
OCT-guided
femtosecond
laser
Crosslinking

8. Subjects
• 10 eyes of 9 ectatic patients (Male: 7 eyes of 6 patients; Female: 3 eyes of 3 patients)
Surgical Method
1. Tunnel creation using OCT-guided femtosecond laser (Femto LDV Z6, Ziemer,
Port, Switzerland)
2. Insertion of ring(s)
3. 0.25% Riboflavin injection into the tunnel. Soak for 5 min.
4. UVA irradiation (45 mW/cm2, 2 min 40 sec)
Pre and Postoperative examination
• Uncorrected and corrected distance visual acuity (UDVA and CDVA)
• Manifest refraction
• K mean (Pentacam)
• K max (Pentacam)
• Corneal higher order aberrations (corneal HOAs)
• Corneal endothelial cell density (ECD)
• Central corneal thickness (CCT)
• Corneal topography (Pentacam)

9. Femto LDV Z6 ~ OCT guided femtosecond laser
Depth of the tunnel is virtually confirmed for the precise ring implantation.
Vertical Scan
“C” shaped tunnel
Horizontal Scan
Vertical Scan
▲Before
cut
▲After
cut
Ziemer (Port, Swiss)
Horizontal Scan
▲Before
cut
▲After
cut

10. Surgical Video

11. UDVA and CDVA (Decimal/Snellen)
1.4
*
*
1.27
1.2
(20/16)
1.27
1.20
1
(20/20)
0.99
**
**
0.8
(20/25)
0.6
0.66
(20/32)
0.69
0.52
0.4
UDVA
(20/50)
CDVA
0.2
(20/100)
*P *P 0.0077
= = 0.0077
**P 0.0180
**P = = 0.0180
0.19
0
Pre
(n
=
1 0)
1W
(n
=
1 0)
1M
(n
=
1 0)
3M
(n
=
1 0)
*Wilcoxon signed-rank test
ü After 3 months, UDVA and CDVA were significantly improved from preoperative.

12. Spherical and Cylindrical change
Sphere (D)
Cylinder (D)
2
0
-­‐1
1
0.35
-­‐0.10
0
-­‐0.23
-­‐2.25
-­‐2
*
-­‐2.38
-­‐2.38
-­‐3
-­‐1.05
-­‐1
-­‐4
-­‐2
*P = 0.0166
-­‐4.25
-­‐5
Pre
(n
=
1 0)
1W
(n
=
10)
1M
(n
=
10)
3M
(n
=
10)
Pre
(n
=
1 0)
1W
(n
=
10)
1M
(n
=
10)
3M
(n
=
10)
ü After 3 months, cylinder was significantly improved from preoperative.
*Wilcoxon signed-rank test

13. K mean and K max
K mean (D)
K max (D)
46
56
42
*
*
44
42.88
41.60
52
51.88
41.50
41.54
49.31
48.72
48
48.41
40
*P = 0.0051
38
*P = 0.0117
44
Pre
(n
=
10)
1W
(n
=
10)
1M
(n
=
10)
3M
(n
=
10)
Pre
(n
=
10)
1W
(n
=
10)
1M
(n
=
10)
3M
(n
=
10)
ü After 3 months, K mean and K max were significantly improved from preoperative.
*Wilcoxon signed-rank test

14. Corneal Higher Order Aberrations
S3 (μm)
S4 (μm)
3
2
*
2.5
1.6
2
1.5
2.02
1.23
0.8
1
0.99
0.5
*P = 0.0117
0
Pre
(n
=
1 0)
*
1.2
1M
(n
=
8 )
3M
(n
=
10)
1.08
0.82
0.4
0.59
*P = 0.0499
0
Pre
(n
=
1 0)
1M
(n
=
8 )
3M
(n
=
10)
ü After 3 months, corneal HOA s were significantly improved from preoperative.
*Wilcoxon signed-rank test

15. ECD and CCT
ECD (cells/mm2)
NS*
3500
3000
CCT (μm)
2912
3020
NS*
500
2843
424.1
2903
422.7
425.2
422.5
Pre
(n
=
10)
1W
(n
=
10)
1M
(n
=
1 0)
3M
(n
=
10)
400
2500
2000
300
1500
200
1000
100
500
0
0
Pre
(n
=
10)
1W
(n
=
9 )
1M
(n
=
10)
3M
(n
=
9)
*NS = Not significant
ü After 3 months, ECD and CCT did not change significantly from preoperative.
*Wilcoxon signed-rank test

16. Corneal Topography
Pre OP
3M Post OP
Difference
ü Corneal topography was improved from preoperative after 3 months.

17. ü At 3 months postoperative, Uncorrected and Corrected distance visual
acuity, cylinder, K-value (mean and max), and corneal HOAs were
significantly improved from preoperative.
ü No significant difference was observed in ECD and CCT after 3
months postoperative when compared to preoperative value.
ü Corneal topography was improved following the treatment.
ü Using OCT-guided Femto LDV Z6, the tunnel for the ring implantation
was safely created.
Simultaneous Keraring implantation using OCT-guided Femto LDV V6 and
Crosslinking was effective for the treatment of keratectasia

18. Thank
you
for
your
a]en+on!
April 1, 2014
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