Transcript Evaluation & Surgical Correction of Astigmatism

Evaluation & Surgical Correction of
Astigmatism
Jean Luc Febbraro MD
Rothschild Foundation
Paris
France
[email protected]
Evaluation & Surgical Correction of
Astigmatism
Financial disclosure
Alcon Laboratories: C, Croma: C
Bausch & Lomb Surgical: C,L
Surgical Correction of Astigmatism
Evaluation & Principles
 Prevalence
& Evolution
 Cataract incisions
SIA
Evaluation of Astigmatism
• K-readings
– 2mm central
• Topography
– Placido, Scheimflug (cornea > 2mm)
– Aberrometers (cornea, internal)
• Refraction
– Total astigmatism (subjective, objective)
Evaluation of Astigmatism
 Topography (placido)
 Precise measurement




Magnitude, axis
Symmetry
Regularity
Detection
 K. fruste
 Pellucid Deg.
Evaluation of Astigmatism
 Aberrometers (Hartman-Shack,
OPD)
 Precise measurement
 Lower order ab. (Sph, cyl.)
 Higher order ab. (coma,
trefoil, sph. aberrations)
 Distinction
 Total, internal
Evaluation of Astigmatism
• Refraction (Subjective, objective)
– Perfect match required
• Subjective
– (Sph, cyl)
• Objective
– (Sph, cyl & HOA)
• Enable WF ablation
Astigmatic Correction & Cataract
Patients
 Surgical options:
• Incisional techniques
• LRI, AK
• Toric IOLs
• Laser vision correction
• PRK, LASIK
Astigmatic Correction & Incisional
Techniques
 Principles:
• The cornea flattens over an incision
• Transverse incisions increase the radius of
curvature in one meridian only
• The flattening effect increases as incisions
approach the visual axis
Astigmatic Correction & Incisional
Techniques
 Coupling:
 The flattening effect of a transverse incision is
associated with a steepening effect 90° away.
• Coupling ratio tend to be one to one.
• The spherical equivalent remains unchanged.
Astigmatic Correction & Incisional
Techniques
 Principles:
 Incisions are always placed on the steep
meridian.
• The longer and deeper the incision the greater
the effect.
• The older the patient the greater the effect.
Astigmatic Correction with LRI
LRI / PRI
 Placed on the steepest meridian
 Located at the limbus (9.0-11.0-mm OZ)
44
42
Astigmatic Correction with LRI
Principles
 Flatten the steepest meridian
 Steepen the axis at 90°
 Coupling ratio 1:1
42
44
43
43
Astigmatic Correction: LRI / AK
LRI: pros
 Less irregular astigmatism
 Less chance of perforation
 Convenient technique
 Easy to perform
 Intraoperatively
Astigmatic Correction: LRI / AK
LRI: cons
 Limited astigmatic correction
 Regression
 Variability of results
Astigmatic Correction: LRI
Instruments: simple kit
 Axis marker
 0.12-caliber forceps
 Diamond knife
 Preset (600 microns)
 Micrometer
STUDY
 46 eyes, 30 patients (age: 72 + 10 A)
•
•
•
•
•
3.2 mm CCI, Steep axis
Preset 600 µ diamond knife
Limbal relaxing incisions
Preop Corneal Astig.: 1.66 + 0.65 D (0.75 to 3)
Follow up: 6 M
Results:
Astigmatism pre / postop
As tigm
atis m e cornŽ
en
(D)
Corneal
Astigmatism
(D)
Preop
1,8
1,66
1,6
1,4
20/20
20/25
20/40
Postop
67
78
1,66
0,98
1,2
1
0,68
0,8
0,6
0,4
0,2
0
Preop
Postop
Correction
Correction
70
78
0,68
72
78
0,98
LRIs: Tips & Tricks
Placement of incisions
• Axis
– 10° off: -33%
– 15° off: -52%
•
•
•
•
Constant orientation
Constant depth
Preset 600µ knife
Micrometer knife set at 90%
thinnest pachymetry
• Steep axis +++
Astigmatic Correction withToric
IOLs
Reduction of Astigmatism
 SN60T3 = 1.5D (1D)
 SN60T4 = 2.25D (1.5D)
 SN60T5 = 3.0D (2D)

Astigmatic Correction withToric
IOLs
FDA Data




92% 20/40 or better
Mean residual astigmatism: 0.60 D
50% less than 0.5D of residual postop astigmatism
97.6% rotated less than 15 degrees
Astigmatic Correction with Laser
Laser Vision Correction:
 Precise correction of astigmatism
 Correction of spherical component
 Check MR and WF refraction
Astigmatic Correction with Laser
n=340
n=206
n=139
Netto et al, AJO 2006;141:360-368
Laser Astigmatic Vision Correction
Refractive patients: primary choice




PRK
LASIK
Excellent accuracy (sphere & cylinder)
Constant technological improvements
Laser Astigmatic Vision Correction
All types of regular astigmatisms
 Simple, compound myopic astig.
 Flatten the steepest meridian
 Simple, compound hyperopic astig.
 Steepen the flattest meridian
 Mixed astig.
 Combine both principles
Cyclotorsion & Astigmatic Correction
Angle Error (Degrees)
Undercorrection in Astigmatism
35.0%
30.0%
25.0%
20.0%
15.0%
10.0%
5.0%
0.0%
0
1
2
3
4
5
6
Angle Error (Degrees)
7
8
9
10
Iris Recognition
ACE
SRET
DRET
Static Rotational ET
Dynamic Rotational ET
Compensation between
upright / supine position
Intraoperative compensation
Cyclotorsion
Study
Eyes
Mean Degree
Movement
Other
Febbraro et al.
JCRS, 2010
70
3.4 + 2.7º
up to 14º
4.1º + 3.7º
8% with over
10º of
movement
-
25% over 7º of
movement
(up to 16º)
Swami, Steinert et
al,
AJO, 2002
Smith, Talamo,
Assil,
JCRS, 1994
240
50
Results
Cyclotorsion:
Static (SRET) / Dynamic (DRET)
ACE
SRET
DRET
Mean
3.08 + 2.68 °
3.39 + 2.94°
Range
-7 - +14.1°
-10.3 - +13.5°
Fondation A. de Rothschild
Paris
Jean-Luc Febbraro
MD
ACE
Mean Static (SRET) / Dynamic (DRET)
N:70
%
Cyclotorsion
Fondation A. de Rothschild
Paris
Jean-Luc Febbraro
MD
ACE
Mean Absolute Amplitude (DRET)
40
Mean amplitude: 2.69 +
1.35°
(range 0 – 9.2°)
Frequency (eyes)
35
30
25
20
15
> 2°: 74%
> 5°: 4%
10
5
0
1
2
3
4
5
6
7
8
9
10
11
DRET Amplitude
(°)
Fondation A. de Rothschild
Paris
Jean-Luc Febbraro
MD
Conclusion
•
Surgical correction of astigmatism is
a reality
– Mandatory to optimize uncorrected vision
– Refractive and cataract patients
– Numerous surgical options
Fondation A. de Rothschild
Paris
Jean-Luc Febbraro
MD
• Clinical significance
– Accurate eye care
– IOL manufacturers (SA , Cyl.)
– Valuable information for cataract &
refractive surgeons
Astigmatism evolution with age
Age / Ast.
2654 patients
%
Mean
20-30 years
40%
1.20 D
70-80 years
72%
1.30 D
Prevalence of astig. increases with age.
Ferrer-Blasco T. et al. JCRS 2008; 34:424-432
To evaluate Astigmatism Distribution and Evolution in
Adult Patients
 Retrospective study
 500 eyes of 276 patients
 Autorefractometer refraction & keratometry
measurements
 Mean interval: 8.37 +/-2.92 y (min 5-16 max)
Mean age
60.11 +/- 11.39
Age min- Age max
37-90
Gender: Male / Female
182 M / 318 F
Mean sphere
-0.02 +/- 3.20
Sphere min-max
-14.75 - + 7.5
Mean ocular astigmatism
0.95 +/- 0.77
Ocular astig. min-max
0.25 - 6.75
Mean corneal astigmatism
1.14 +/- 0.40
Corneal astig. min-max
0 - 6.5
Mean flat K (K1)
43.10 +/- 1.39
Mean steep K (K2)
44.11 +/- 1.48
Astigmatism Distribution
Magnitude
Ocular Astig.
Corneal Astig.
≤0.5D
35.8%
33.8%
0.75 - 1D
36.6%
33.4%
1.25 - 2D
20.8%
23.8%
> 2D
6.8%
8.2%
Astigmatism Evolution
diopters (D)
visit 1
1.4
1.2
1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
1.14
1.14 *
0.95 *
OCULAR
AST.
CORNEAL AST.
0.95
-0.02
SPHERE
- 0.31
visit 2
Astigmatism Evolution
Age Groups
Cylinder
Axis
< 50
0.19 +/- 0.64D
6 +/- 17°
50-59
0.24 +/- 0.71D
12 +/- 20°
60-69
0.31 +/- 0.75D
6 +/-17°
> 70
0.28 +/- 0.89D
5 +/- 15°
ATR shift over 8 years
0.26 D
Astigmatism Evolution
Age Groups
Study
500 eyes
Reykjavic Eye Study*
757 eyes
< 50
0.19 +/- 0.64 D
50-59
0.24 +/- 0.71D
0.09 +/- 0.41 D
60-69
0.31 +/- 0.75D
0.13 +/- 0.45 D
> 70
0.28 +/- 0.89D
0.22+/- 73°
All Groups
O.26 D over 8 years
0.13 D over 5 years
* E. Gudmundsdottir, A. Arnarsson, F. Jonasson. Five-year refractive
changes in an adult population; Reykjavik Eye Study. Ophthalmology
2005;112, 672–677.
 Knowledge of prevalence and evolution of
astigmatism is valuable information
 35% negligible astig.
 35% 0.75 – 1 D
 30% > 1 D 7% 2 D
 Mean magnitude +/- 1 D in adults, tends to increase
with age
 ATR axis shift (0.13 – 0.26 D) over time, particularly
in older patients
• Trend
 Size
 Standard 3-mm incision
 Mini + 2.5-mm incision
 Micro sub 2-mm incision
 Placement
 Scleral to limbal / clear corneal incision
 Superior to temporal approach
• Size
 IOL implantation
Monofocal, Multifocal, Accomodative, Toric IOLs
 Phaco platform
Phaco and I/A probes & sleeves
• Location
 Scleral to limbal / clear corneal incision
 Superior to temporal approach
• Astigmatic change
 Incision size
 Distance from visual axis
 Axis placement
• Astigmatic change evaluation
 Algebraic method (magnitude of ast.)
 Vector Analysis (magnitude & axis of ast.)
Standard 3-3.5-mm on axis CCI PKE
n: 172
Sup. Incision
Temp. Incision
SIA
0.93 + 0.54 D
0.62 + 0.47 D
Long D. et al. Ophthalmology 1996; 103:226-232
Standard 3.2-mm on axis / temp. CCI PKE
n: 62
On Axis
Incision
Temporal
Incision
SIA
7 w PO
0.63 D
0.34 D *
Borasio E. et al. JCRS 2006; 32:565-572
3-3.5-mm Incision & SIA Range
Literature Summary
Incision
Location
SIA (D)
Superior
Oblique
0.60 – 1.50 0.60 – 1.29
On Axis
Temporal
0.60 – 0.90
0.09 – 0.44 *
Choice of Incision Location
Temporal Inc.
Nasal Inc.
Superior Inc.
WTR
0.75-1.25 D
1996
Kohnen T, Koch D.1
ATR
0.75-1.25 D
2005
Tejedor J, Murube J.2
ATR < 0.75 D
ATR > 0.75 D
WTR >1.25 D
2009
Tejedor J, Perez J.3
Negligible Ast.
ATR
WTR
1 Kohnen T, Koch D. Curr Opin Ophthalmol. 1996; 7:75-80
2 Tejedor J, Murube J. Am J Ophthalmol. 2005; 139:767-776
3 Tejedor J, Perez-Rodriguez J. IOVS. 2009; 50:989-994
n: 44
3.0-mm
2.2-mm
SIA
0.67 + 0.48 D
0.35 + 0.21 D *
Masket S. et al. JRS 2009; 25:21-2424
n: 108
C-MICS
B-MICS
SIA
0.23 + 0.29 D
0.23 + 0.22 D
Wilczynski M. et al. JCRS 2009; 35:1563-69
STUDY
Evaluate SIA Cataract Incisions
•
Nonrandomized prospective series 191 eyes
• Group 1: 60 eyes PKE 3.2-mm sup. CCI
• Group 2: 68 eyes PKE 2.2-mm sup. CCI
• Group 3: 63 eyes PKE 1.8-mm sup. CCI
•
•
Two-plane incision with precalibrated metal knife
Unenlarged wound for IOL implantation
• Group 1: SN60WF / Akreos AO IOLs
• Group 2: SN60WF / Akreos MICS IOLs
• Group 3: Akreos MICS IOL
Study
Results
Vector Analysis
Group
Arithmetic Mean
Vector Mean
3.2-mm
1.02 + 0.39 D
0.77 at 10°
2.2-mm
O.60 + 0.20 D
0.26 at 20°
1.8-mm
O.48 + 0.10 D
0.16 at 13°
• Desirable to know astigmatic effect of CCI
• SIA depends on incision size and location.
• Significant less SIA with 1.8 / 2.2 / + 3.0-mm CCI.
• SIA very limited with + 2.0-mm CCI.
• Desirable to know astigmatic effect of CCI
• SIA depends on incision size and location.
• Significant less SIA with 1.8 / 2.2 / + 3.0-mm CCI.
• SIA very limited with + 2.0-mm CCI.
• Clinical implications
• To minimize SIA & optimize visual rehabilitation.
• Customized incision size and location (>2.8-mm) based upon preop.
astig.
• Optimize UCVA with monofocal & premium IOLs.
Thank you
for your attention
Fondation A. de Rothschild
Paris
Jean-Luc Febbraro
MD