Transcript Stability of LASIK Performed on Topographic Suspect

One and two-year clinical outcomes of
LASIK for high hyperopia
Dan Z Reinstein MD MA(Cantab) FRCSC1,2,3,4
Timothy J Archer, MA(Oxon), DipCompSci(Cantab)1
Marine Gobbe, MSTOptom, PhD1
1. London Vision Clinic, London, UK
2. St. Thomas’ Hospital - Kings College, London, UK
3. Weill Medical College of Cornell University, New York
4. Centre Hospitalier National d’Ophtalmologie, (Pr. Laroche), Paris, France
Financial Disclosure:
The author (DZ Reinstein) acknowledges a financial interest in Artemis™ VHF digital
ultrasound (ArcScan Inc, Morrison, CO)
The author (DZ Reinstein) is a consultant for Carl Zeiss Meditec AG (Jena, Germany)
©DZ Reinstein 2009
[email protected]
Methods - Patients
• 636 eyes
• 371 patients
• Age: 18 to 78 years, median 51
years
• BSCVA: 66% ≥ 20/20
• Hyperopia: +4.00 to +7.50 D,
mean +5.35 ± 1.01 D
• Cylinder : 0.00 to -3.00 D,
mean -0.98 ± 0.70 D
Distribution of Maximum Hyperopia
20%
• Enhancement rate: 25%
– This includes patients who could
see 20/20
– If enhancement had been
denied for 20/25 or better,
the enhancement rate would
have been 9%
16%
16%
Percentage Eyes
• Planned two-stage treatments
= 20% (none enhanced)
18%
18%
14%
12%
12%
11%
13%
10%
10%
9%
8%
6%
4%
2%
0%
Series1
4.00 To
4.49
4.50 To
4.99
5.00 To
5.49
5.50 To
5.99
6.00 To
6.49
6.50 To
6.99
7.00 To
7.50
11%
18%
16%
12%
13%
10%
9%
Maximum Hyperopia (D)
• Surgery: MEL80 excimer Laser,
Hansatome microkeratome or
Visumax femtosecond
Visual axis centration
Optical zone: 7 mm
©DZ Reinstein 2009
[email protected]
Methods: Corneal Vertex Centration
Example: Eye with a large nasal angle kappa
I
I
N
T
N
T
S
+
Pupil centre
Orbscan Anterior
Elevation Map
N
T
S
+
I
I
S
Corneal Vertex
Orbscan Eye Image
Pupil margins
Hansatome flap centred
with corneal vertex
N
T
S
Flap edge
MEL80 Eye Tracker
aligned with corneal
vertex
• Flap and corneal ablation centred on the corneal vertex
• Corneal vertex best approximates the visual axis
No difference in outcomes (accuracy, safety, contrast sensitivity) between a group of eyes
with a small angle kappa (pupil centre  corneal vertex) and group of eyes with a large angle
kappa (pupil offset ≥ 0.55 mm) [1]
Corneal ablation should be centred on the corneal vertex ( visual axis) and not
the pupil centre (line of sight)
[1] Reinstein et al – Centration of hyperopic ablations: corneal vertex vs pupil centre – AAO, Atlanta, 2008.
©DZ Reinstein 2009
[email protected]
Methods: Artemis Two-stage treatment
Artemis two-stage treatment for refractions over +5.50D
1. Primary treatment: up to +5.50D in the maximum hyperopic meridian
2. Post-operative Artemis
Measurement of thinnest epithelium
Calculation of treatable remaining hyperopia based on
minimum epithelial thickness
140
140
Thickest Epithelium
Thickest Epithelium
Thinnest Epithelium
100
y = 7.2619x + 57.718
R2 = 0.8167
80
60
40
20
0
0.00
y = -1.7158x + 46.819
R2 = 0.3032
2.00
4.00
6.00
Attempted
AttemptedSEQ
SEQ
8.00
10.00
EpithelialThickness
Thickness
Epithelial
Epithelial
Thickness
Thickness
Epithelial
120
120
y = 2.3437x - 24.437
R2 = 0.1399
Thinnest Epithelium
100
80
60
40
20
0
40.0
y = -0.7217x + 73.843
R2 = 0.0886
42.0
44.0
46.0
48.0
50.0
52.0
Epithelial thickness
is a more reliable tool
than keratometry to
determine the amount of
ablation that can be
performed [1]
54.0
MaxMaxSim
K
Sim K
Patient could have a flat cornea, but thin epithelium:
Patient could have a steep cornea, but thick epithelium:
not suitable for retreatment
suitable for retreatment
[1] Reinstein et al. Epithelial Thickness After Hyperopic LASIK: Three-dimensional Display With Artemis Very High-frequency Digital Ultrasound. J
Refract Surg. 2009 Nov 24:1-10
©DZ Reinstein 2009
[email protected]
Results: Accuracy
Within ±0.50 D
62%
Within ±1.00 D
85%
Accuracy: Within Range of Intended
25%
24%
20%
Percentage Eyes
20%
18%
15%
15%
10%
9%
6%
5%
3%
2%
1%
0%
Accuracy
-2.00
To 1.51
-1.50
To 1.01
-1.00
To 0.51
-0.50
To 0.14
-0.13
To
0.13
0.14
To
+0.50
+0.51
To
+1.00
+1.01
To
+1.50
+1.51
To
+2.00
1%
3%
9%
20%
24%
18%
15%
6%
2%
Accuracy of Spherical Equivalent
©DZ Reinstein 2009
[email protected]
Results: Efficacy
(excluding eyes not intended plano)
Efficacy: Monocular UCVA
95%
100%
Monocular UDVA
88%
86%
76%
80%
Percentage Eyes
100%
96%
100%
n=237
mean max hyperopia +5.37 ± 1.00D
70%
59%
60%
40%
26%
17%
20%
1%
0%
3%
20/12.5
20/16
20/20
20/25
20/32
20/40
Pre BSCVA
1%
26%
70%
86%
96%
100%
Efficacy
3%
17%
59%
76%
88%
95%
20/63
Pre-op, 70% of eyes had 20/20 bestspectacle corrected VA.
Post-op, 59% of eyes achieved 20/20
unaided.
100%
Monocular UCVA
Post UCVA vs Pre BSCVA
45%
41%
Post UDVA vs Pre CDVA
40%
Percentage Eyes
35%
83% within 1 line of Pre CDVA
30%
24%
25%
20%
16%
15%
10%
11%
6%
4%
5%
0%
Success
3 or more
worse
2 worse
1 worse
Pre BSCVA
1 better
2 better
5.9%
10.5%
23.6%
40.5%
15.6%
3.8%
Post-op, 83% of eyes achieved
unaided VA that was within 1 line
of the pre-op spectacle corrected
vision.
94% within 2 lines of Pre CDVA
Post UCVA vs Pre BSCVA
©DZ Reinstein 2009
[email protected]
Results: Safety – BSCVA and Contrast Sensitivity
Safety: Lines Change BSCVA
Percentage Eyes
80%
60%
60%
No eyes loss 2 lines or more
40%
22%
17%
20%
0%
Safety
1%
0.0%
0.0%
Loss 3 or
More
Loss 2
Loss 1
No
Change
Gain 1
Gain 2 or
More
0.0%
0.0%
22%
60%
17%
1%
Lines Change BSCVA
*
Slight statistically significant
decrease in contrast sensitivity at
all spatial frequencies
*
*
*
Average decrease: less than 1
patch
Little clinical significance
©DZ Reinstein 2009
[email protected]
Stability
Stability: Change in Spherical Equivalent
Spherical Equivalent (D)
6.00
5.00
4.00
3.00
2.00
1.00
0.00
-1.00
-2.00
Mean±SD
# eyes
3 Mo 6 Mo
12 Mo
24 Mo
Time Point
Pre-op
1 Day
1 Month
3 Months
6 Months
1 Year
2 Years
+4.19±1.38
-0.31±0.62
-0.10±0.75
+0.04±0.75
+0.16±0.78
+0.36±0.85
+0.52±0.94
636
517
561
594
514
405
201
• If we assume that the refraction is stable at 3 months (post-operative oedema has resolved), the
hyperopic shift at 2 years is 0.48 D (0.52 D at 2y – 0.04 D at 3m)
• We know that the average hyperopic shift with age is 0.42 D in 5 years = 0.08 D/year
[1,2]
The hyperopic shift due to LASIK regression is 0.32D at 2 years (0.48D – 0.08 D x 2)
[1] Guzowski et al. Five-year refractive changes in an older population: the Blue Mountains Eye Study. Ophthalmology. 2003 Jul;110(7):1364-70.
[2] Gudmundsdottir et al. Five-year refractive changes in an adult population: Reykjavik Eye Study. Ophthalmology. 2005 Apr;112(4):672-7.
©DZ Reinstein 2009
[email protected]
Outcomes Comparison: Accuracy, Safety, Efficacy of
Phakic IOLs vs LASIK – High Hyperopia
Accuracy within
Efficacy
Loss 2
lines
UCVA≥
20/40
Rx treated
± 0.50D
± 1.00 D
Artisan IOL FDA [1]
+4.00 to +12.00D
65.5%
98.2%
No data
85.5%
Artisan phakic IOL [2]
+2.75 to +9.25 D
50%
78%
0
89%
Posterior chamber phakic
IOL [3]
+4.00 to +11.00D
58%
79%
4%
63%
RLE & multifocal IOL [4]
+1.75 to +6.00D
88%
100%
0
100%
RLE Staar/Rayner IOL [5]
+4.75 to +13.00 D
70%
90%
0
25%
Acrysoft RLE [2]
+2.75 to +7.50 D
55%
91%
0
82%
LASIK – MEL80
+4.00 to +7.00 D
65%
93%
0%
95%
[1] Desai et al - Long-term results of the Artisan IOL for the correction of severe and extreme hyperopia in the United States: A prospective
Multi-Center Study – ARVO 2008.
[2] Pop M. Payette Y. Refractive lens exchange versus iris-claw Artisan Phakic Intraocular Lens for Hyperopia. J Refract Surg. 2004;20:20-24
[3] Davidorf et al – Posterior chamber phakic intraocular lens for hyperopia +4 to +11 diopters. J Refract Surg. 1998; 14(3): 306-311
[4] Dick et al – Refractive lens exchange with an array mutifocal IOL – J Refract Surg. 2002;18:509-518
[5] Preetha et al – Clear lens extraction with intraocular lens implantation for hyperopia. J Cataract Refract Surg. 2003;29: 895-899
©DZ Reinstein 2009
[email protected]
Conclusion
• Equal or better outcomes than IOLs
• Risks associated with IOLs avoided:
–
–
–
No endothelial cell loss (4.3% over 3 years with Artisan IOL [1], 5.4% over 1 year with Kelman
Duet Phakic IOL [2])
No PCO (7.1% to 31.1% with monofocal IOLs [3], 48% with the Tetraflex lens [4])
No other complications associated with intra-ocular surgery
• Epithelial thickness better indicator than keratometry for preventing
apical epitheliopathy
• Centration on corneal vertex (NB opposes convention!)
• Contrast sensitivity: slight reduction but not clinically significant (cf.
Significant loss of CS with multifocal intraocular lenses [5,6])
• Stability: slight hyperopic shift over 2 years (+0.32D)
[1] Desai et al - Long-term results of the Artisan IOL for the correction of severe and extreme hyperopia in the United States: A prospective MultiCenter Study – ARVO 2008
[2] Alio et al. The Kelman Duet Phakic Intraocular Lens: 1-year Results. J Refract Surg. 2007;23:868-878
[3] Auffarth et al. Ophthalmic Epidemiol. 2004; 11(4)
[4] Wolffsohn J. Two-year performance of the Tetraflex accommodative IOL. ARVO – May 2008
[5] Alfonso et al. Prospective visual evaluation of apodized diffractive intraocular lenses. J Cataract Refract Surg. 2007;33: 1235-1243.
[6] Schmidinger et al. Contrast sensitivity function in eyes with diffractive bifocal intraocular lenses. J Cataract Refract Surg. 2005;31:2076-2083
©DZ Reinstein 2009
[email protected]