evaluation & surgical correction of astigmatism jean luc febbraro md rothschild foundation paris...
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Evaluation & Surgical Correction of Astigmatism
Jean Luc Febbraro MDRothschild Foundation
Paris France
[email protected]@febbraro.net
Evaluation & Surgical Correction of Astigmatism
Financial disclosureAlcon Laboratories: C, Croma: C
Bausch & Lomb Surgical: C,L
Surgical Correction of Astigmatism
Evaluation & Principles
Prevalence & EvolutionPrevalence & Evolution
Cataract incisions SIA 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)
4242
4444
Astigmatic Correction with LRI
Principles Flatten the steepest meridian Steepen the axis at 90° Coupling ratio 1:1
4444
42424343
4343
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
Corneal Astigmatism (D)Corneal Astigmatism (D)
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 astigmatismCorrection of spherical componentCheck MR and WF refraction
Astigmatic Correction with Laser
n=206n=139
n=340
Netto et al, AJO 2006;141:360-368Netto et al, AJO 2006;141:360-368
Laser Astigmatic Vision CorrectionRefractive patients: primary choice
PRK LASIK Excellent accuracy (sphere & cylinder) Constant technological improvements
Laser Astigmatic Vision CorrectionAll 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
Angle Error (Degrees)
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
30.0%
35.0%
0 1 2 3 4 5 6 7 8 9 10
Angle Error (Degrees)
Undercorrection in Astigmatism
Cyclotorsion & Astigmatic Correction
ACE
SRET DRETStatic Rotational ET Dynamic Rotational ETCompensation between Intraoperative compensationupright / supine position
Iris Recognition
Cyclotorsion
Study EyesMean Degree Movement
Other
Febbraro et al.JCRS, 2010
70 3.4 + 2.7º up to 14º
Swami, Steinert et al, AJO, 2002
240 4.1º + 3.7º8% with over 10º of movement
Smith, Talamo, Assil, JCRS, 1994
50 - 25% over 7º of movement (up to 16º)
ACEACE SRETSRET DRETDRET
MeanMean 3.08 3.08 + 2.68 ° 2.68 ° 3.39 3.39 + 2.94° 2.94°
RangeRange -7 - +14.1°-7 - +14.1° -10.3 - +13.5°-10.3 - +13.5°
Results
Fondation A. de Fondation A. de RothschildRothschild
ParisParis
Jean-Luc Febbraro Jean-Luc Febbraro MDMD
Cyclotorsion:
Static (SRET) / Dynamic (DRET)
ACE
%%
Cyclotorsion Cyclotorsion
Mean Static (SRET) / Dynamic (DRET)
Fondation A. de Fondation A. de RothschildRothschild
ParisParis
Jean-Luc Febbraro Jean-Luc Febbraro MDMD
N:70 N:70
ACEMean Absolute Amplitude (DRET)
Fondation A. de Fondation A. de RothschildRothschild
ParisParis
Jean-Luc Febbraro Jean-Luc Febbraro MDMD
DRET Amplitude (°)DRET Amplitude (°)
Conclusion
• Surgical correction of astigmatism is a reality – Mandatory to optimize uncorrected vision– Refractive and cataract patients– Numerous surgical options
Fondation A. de Fondation A. de RothschildRothschild
ParisParis
Jean-Luc Febbraro Jean-Luc Febbraro MDMD
• 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. Ferrer-Blasco T. et al. JCRS 2008; 34:424- JCRS 2008; 34:424-432432
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
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 DistributionAstigmatism Distribution
-0.02-0.02
Astigmatism Evolution
OCULAR OCULAR AST.AST.
visitvisit 11 visitvisit 22
CORNEAL CORNEAL AST.AST.
SPHERESPHERE
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 yearsATR shift over 8 years
0.26 D0.26 D
Astigmatism Evolution
Age GroupsAge Groups Study Study 500 eyes500 eyes
Reykjavic Eye Reykjavic Eye Study* 757 eyesStudy* 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 * E. Gudmundsdottir, A. Arnarsson, F. Jonasson. Five-year refractive changes in an adult population; Reykjavik Eye Study. changes in an adult population; Reykjavik Eye Study. Ophthalmology 2005;112, 672–677.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; 103:226-232Long D. et al. Ophthalmology 1996; 103:226-232
Standard 3.2-mm on axis / temp. CCI PKE
n: 62On Axis Incision
Temporal Incision
SIA7 w PO
0.63 D 0.34 D *
Borasio E. et al. JCRS 2006; 32:565-572Borasio E. et al. JCRS 2006; 32:565-572
3-3.5-mm Incision & SIA RangeLiterature Summary
Incision Location
Superior Oblique On Axis Temporal
SIA (D) 0.60 – 1.50 0.60 – 1.29 0.60 – 0.90 0.09 – 0.44 *
Choice of Incision Location
1 Kohnen T, Koch D. Curr Opin 1 Kohnen T, Koch D. Curr Opin Ophthalmol. 1996; 7:75-80Ophthalmol. 1996; 7:75-80
Temporal Inc. Nasal Inc. Superior Inc.
1996Kohnen T, Koch D.1
ATR 0.75-1.25 D
WTR 0.75-1.25 D
2005Tejedor J, Murube
J.2
ATR < 0.75 D ATR > 0.75 D WTR >1.25 D
2009Tejedor J, Perez J.3 Negligible Ast. ATR WTR
2 Tejedor J, Murube J. Am J Ophthalmol. 2005; 139:767-7762 Tejedor J, Murube J. Am J Ophthalmol. 2005; 139:767-776
3 Tejedor J, Perez-Rodriguez J. IOVS. 2009; 50:989-9943 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; 25:21-2424Masket 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; 35:1563-69Wilczynski M. et al. JCRS 2009; 35:1563-69
STUDYEvaluate 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
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°
Vector Analysis Vector Analysis
StudyResults
• 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.
Fondation A. de Fondation A. de RothschildRothschild
ParisParis
Jean-Luc Febbraro Jean-Luc Febbraro MDMD
Thank youfor your attention