Conductive Keratoplasty for
the Correction of Low to
Moderate Hyperopia:
U.S. Clinical Trial
12-Month Results
U.S. Clinical Investigators
Marguerite McDonald, MD – Medical Monitor
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Penny Asbell, MD
Stephen Brint, MD
William Culbertson, MD
Jonathan Davidorf, MD
Elizabeth Davis, MD
Dan Durrie, MD
R. Bruce Grene, MD
Peter Hersh, MD
David Hardten, MD
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Vera Kowal, MD
Richard Lindstrom, MD
Robert Maloney, MD
Edward Manche, MD
Roger Meyer, MD
Thomas Samuleson, MD
Timothy Schneider, MD
Kaz Soong, MD
Alan Sugar, MD
Conductive Keratoplasty Features
• Treats hyperopia, astigmatism, presbyopia and
over/under LASIK corrections
• Induces permanent collagen shrinkage
• Creates a column of treatment
• Utilizes cornea’s conductive properties
ViewPoint™ CK System
The Keratoplast™ tip (90 µm wide, 450 µm long)
with coated stop at the distal end
(shown next to a 7-0 suture)
Conductive Keratoplasty (CK)
Study Objective
• US FDA Phase III Study
• 400 Patients
– Spherical hyperopia 0.75 D to 3.00 D
– < 0.75 D of cylinder
– No prior refractive surgery
– No significant ocular/physical history
• 24 Month Follow-Up
Demographics
Number of Patients
Number of Eyes
Mean Age
Range
Mean Preoperative MRSE
Median MRSE
Mean Preoperative CRSE
233
401
55 +/- 5.4 years
(40 to 74)
+1.82 +/- 0.60 D
+1.75 D
+1.86 +/- 0.63 D
Simple Procedure
•
•
•
•
Instill topical anesthesia
Insert lid speculum (return path for energy)
Mark eye
Apply treatment
Total time less than 5 minutes
Conductive Keratoplasty (CK)
Number, Location, and Sequence of
Treatment Spots
8 spots
16 spots
(0.75 to 0.875 D)
(1.00 to 1.625 D)
Sequence
5
1
8
3
4
7
24 spots
32 spots
(1.75 to 2.25 D)
(2.375 to 3.00 D)
2
6
6 mm OZ
7 mm OZ
8 mm OZ
Slit Lamp Photo 1 Hour After CK
Small leucoma
Visible striae
Percent
Postoperative UCVA Over Time
100
90
80
70
60
50
40
30
20
10
0
90 93 92
86
56
4550
40
6364
73 75
Month 3
N=358
Month 6
N=352
Month 9
N=347
Month 12
N=318
20/20 or >
20/25 or >
20/40 or >
Accuracy of Achieved Refraction
Percent
100
90
80
70
60
50
40
30
20
10
0
83
56
88 87 89
9799 99 99
Month 3
N=358
Month 6
N=352
Month 9
N=347
Month 12
N=318
61 64 63
+/- 0.5 D
+/- 1.0 D
+/- 2.0 D
MRSE Stability through 12 Months
Percent
Patients with Consecutive Visits
100
90
80
70
60
50
40
30
20
10
0
87
83
98 99
89
74
<0.50 D
<0.75 D
<1.00 D
3 to 6 Mo.
Mean Change
in MRSE
Conf. Interval
96 98
93
6 to 9 Mo.
9 to 12 Mo.
0.25 D (0.50)
0.11 D (0.41)
0.11 D (0.35)
0.19, 0.31
0.07, 0.15
0.07, 0.15
Safety Variables
 2 lines lost BSCVA
12 Months
N=383
2%
 > 2 lines lost BSCVA
0.0%
 BSCVA Worse than 20/40
0.0%
 Increase >2.00 D Cylinder
0.3%
 Pre-Op 20/20, Post-op 20/25
0.0%
Induced Cylinder >2.00 D
CK vs. Non-Contact LTK
Post-op Month
LTK1
CK2
1 Month
3.4%
3.0%
3 Months
1.4%
2.0%
6 Months
0.9%
1.0%
12 Months
0.2%
0.3%
1Sunrise
LTK FDA Clinical Study, 2Conductive Keratoplasty 12-Month FDA
Clinical Study Results.
Summary Efficacy Variables
FDA
Guideline
6 Mos.
(N = 352)
12 Mos.
(N = 318)
UCVA < 20/20
50%
45%
56%
UCVA < 20/25
Not Stipulated
64%
75%
UCVA < 20/40
85%
90%
92%
MRSE + 0.50
50%
61%
63%
MRSE + 1.00
75%
88%
89%
Data from patients with single treatment. No retreatments included.
Conductive Keratoplasty:
Case Study
• Preoperative
–
–
–
–
–
50 year old
Female
African American
Good health
No ocular history
– 6 mm pachymetry: 556 µm
– IOP: 15 mm Hg
• Preoperative
– UCVAD: 20/125
– UCVAN: J12
– Manifest RX:
+ 3.25 – 0.75 X 130
– Cycloplegic RX:
+ 3.25 – 0.25 X 130
– BSCVAD: 20/25
Conductive Keratoplasty:
Case Study
• Operative
– Instilled three drops topical anesthesia
– Inserted lid speculum
– Applied 32 treatment spots
– Removed lid speculum
– Instilled NSAID and antibiotic
– Immediate K-Readings:
• 51.75 @ 180 X 49.62 @90
Conductive Keratoplasty:
Case Study
• 1 Day Post-Operative
– UCVAD: 20/32
– UCVAN: J7
– Manifest RX:
+ 1.50 – 0.50 X 120
– BSCVAD: 20/20
– BSCVAN: J2
– Slit Lamp: small epithelial defects
Conductive Keratoplasty:
Case Study
• 1 Month Post-Operative
– UCVAD: 20/20
– UCVAN: J2
– Manifest RX:
- 0.25 – 0.75 X 125
– BSCVAD: 20/20
– BSCVAN: J1
– Slit Lamp Exam: WNL
Conductive Keratoplasty:
Case Study
• 3 Month Post-Operative
– UCVAD: 20/32
– UCVAN: J2
– Manifest RX:
plano – 1.00 X 125
– BSCVAD: 20/16
– BSCVAN: J1
– Slit Lamp Exam: WNL
Conductive Keratoplasty:
Case Study
• 6 Month Post-Operative
– UCVAD: 20/30
– UCVAN: J2
– Manifest RX:
+ 0.25 – 0.75 X 125
– BSCVAD: 20/25
– BSCVAN: J1
– Slit Lamp Exam: WNL
Conductive Keratoplasty:
Case Study
• 12 Month Post-Operative
– UCVAD: 20/20
– UCVAN: J2
– Manifest RX:
+ 0.25 – 0.25 X 110
– BSCVAD: 20/16
– BSCVAN: J1
– Slit Lamp Exam: WNL
Conductive Keratoplasty:
Case Study
• Preoperative
–
–
–
–
50 year old Female
UCVAD: 20/125
UCVAN: J12
Manifest RX:
+ 3.25 – 0.75 X 130
– BSCVAD: 20/25
• 12 Months Post-op
– UCVAD: 20/20
– UCVAN: J2
– Manifest RX:
+ 0.25 – 0.25 X 110
– BSCVAD: 20/16
No retreatment. Spherical correction only
Corneal Topography: Case Study
Preoperative
12 month Post-op
Confocal View Of CK
Folds Between Treatment Spots
Sabry, McDonald, Klyce - 2001
Confocal View Of CK
Deep CK Treatment With Healthy Endothelium
Sabry, McDonald & Klyce - 2001
Cylindrical Footprint of CK
Summary of Phase III Study
• Highly effective
– comparable to H-LASIK
• Stability at 6 months
• Safe – low rate induced cylinder
• Penetration depth confirmed by
histology, confocal microscopy
Summary of Phase III Study
• Topography shows central corneal
steepening with mid-peripheral
flattening
• Visual axis spared
• Multicenter study continues for two
years