- •Preface
- •Contributors
- •Contents
- •Introduction
- •Literature Review
- •Major Issues
- •Major Studies
- •Negative Studies
- •References
- •1.1.1 Introduction
- •1.1.3 Torsional Ultrasound
- •1.1.4 Our Procedure for Emulsifying the Nucleus
- •References
- •1.2 Transitioning to Bimanual MICS
- •1.2.1 Introduction
- •1.2.2 Technique
- •1.2.3 Summary
- •1.3 0.7 mm Microincision Cataract Surgery
- •1.3.1 Sub 1 mm MICS: Why?
- •1.3.3 Instrumentation
- •1.3.3.2 0.7 mm Irrigating Instruments
- •1.3.4 Surgery
- •1.3.4.1 Incision
- •1.3.4.2 Capsulorhexis
- •1.3.4.3 Hydrodissection
- •1.3.4.4 Prechopping
- •1.3.5 0.7 mm MICS Combined Procedures
- •1.3.5.1 0.7 mm MICS and Glaucoma Surgery
- •1.3.6 Summary
- •References
- •2. MICS Instrumentation
- •2.1 MICS Instrument Choice: The First Step in the Transition
- •2.2 MICS Incision
- •2.3 MICS Capsulorhexis
- •2.4 MICS Prechopping
- •2.5 MICS Irrigation/Aspiration Instruments
- •2.5.1 19 G Instruments
- •2.5.2 21 G Instruments
- •2.6 MICS Auxiliary Instrument
- •2.6.1 Scissors
- •2.6.2 Gas Forced Infusion
- •2.6.3 Surge Prevention
- •2.7 New MICS Instruments
- •2.7.1 Flat Instruments
- •References
- •3.1 Introduction
- •3.2 Power Generation
- •3.3.1 Tuning
- •3.2.2 Phaco Energy
- •3.2.2.1 Low Frequency Energy
- •3.2.2.2 High Frequency Energy
- •3.2.3 Transient Cavitation
- •3.2.4 Sustained Cavitation
- •3.3.1 Alteration of Stroke Length
- •3.3.2 Alteration of Duration
- •3.3.2.1 Burst Mode
- •3.3.2.2 Pulse Mode
- •Micro Pulse (Hyper-Pulse)
- •Pulse Shaping
- •3.3.3 Alteration of Emission
- •3.4 Fluidics
- •3.5 Vacuum Sources
- •3.6 Surge
- •3.7.1 Micro-incisional Phaco
- •3.7.2 Bimanual Micro-Incisional Phaco
- •3.7.3 Micro-Incisional Coaxial Phaco
- •3.7.3.1 Irrigation and Aspiration
- •3.8 Conclusion
- •Reference
- •Further Reading
- •4.1 Introduction
- •4.3 Incision Size
- •4.4 Torsional Ultrasound
- •4.5 Conclusion
- •References
- •5. Technology Available
- •5.1 How to Better Use Fluidics with MICS
- •5.1.1 Physical Considerations
- •5.1.1.2 Chamber Stability
- •5.1.1.3 Holdability
- •5.1.2 Surgical Considerations
- •5.1.2.2 Phaco Technique
- •5.1.2.4 The OS3 and CataRhex SwissTech Platforms
- •Equipment
- •Machine Settings
- •5.2 How to Use Power Modulation in MICS
- •5.2.1 Introduction
- •5.2.3 The Concept of Unoccluded Flow Vacuum
- •5.2.4 The Intricacies of Ultrasound Power Modulation
- •5.2.5 The Variable Incidence of Wound Burn Rates
- •References
- •5.3 MICS with Different Platforms
- •5.3.1 MICS with the Accurus Surgical System
- •5.3.1.1 Introduction and Historic Background
- •5.3.1.3 Surgical Parameters for MICS with Accurus
- •5.3.1.4 Final Considerations
- •5.3.2.1 Introduction
- •5.3.2.7 Technology for MICS on the AMO Signature
- •5.3.2.8 Applying Signature Technology to CMICS and BMICS
- •5.3.3 MICS with Different Platforms: Stellaris Vision Enhancement System
- •5.3.3.2 Evaluating the Stellaris Vision Enhancement System
- •5.3.3.3 The Advantages of BMICS
- •References
- •6.1 Pupil Dilation and Preoperative Preparation
- •6.1.1 Managing the Small Pupil
- •6.1.2 Techniques that Depend on the Manipulation of the Pupil
- •6.1.3 Iris Surgery
- •6.1.4 Preoperative Preparation and Infection Prophylaxis
- •6.1.5 Evaluating Risk
- •6.1.6 Assessing Your Approach
- •6.1.7 Preventing Infection, Step by Step
- •6.1.8 Sample Protocol Outline
- •6.1.9 A Careful, Critical Eye
- •References
- •6.2 Incisions
- •References
- •6.3 Thermodynamics
- •6.3.1 Introduction
- •6.3.2 Corneal Thermal Damage
- •6.3.3 Heat Generation
- •6.3.4 Factors that Contribute to Thermal Incision Damage
- •6.3.4.1 Energy Emission: Amount and Pattern of How the Energy Is Delivered
- •6.3.4.3 Viscoelastic Devices and Possible Occlusion of the Aspiration Line
- •6.3.4.4 Irrigation Flow
- •6.3.4.5 Position of the Tip Inside the Incision
- •6.3.4.6 Tip Design
- •6.3.4.7 Surgical Technique
- •6.3.5 Conclusion
- •6.4 Using Ophthalmic Viscosurgical Devices with Smaller Incisions
- •6.4.1 Introduction
- •6.4.1.1 The Nature of OVDs: Rheology
- •6.4.1.3 Soft Shell and Ultimate Soft Shell Technique (SST & USST)
- •6.4.2 Routine, Special and complicated Cases
- •6.4.2.1 Phakic and Anterior Chamber IOLs
- •6.4.2.3 Fuchs’ Endothelial Dystrophy
- •6.4.2.5 Capsular Staining for White & Black Cataracts
- •6.4.2.6 Flomax® Intraoperative Floppy Iris Syndrome USST
- •6.4.3 Discussion
- •References
- •6.5 Capsulorhexis
- •References
- •References
- •6.7 Biaxial Microincision Cataract Surgery: Techniques and Sample Surgical Parameters
- •6.8.1 Surgical Technique
- •6.8.2 Advantages
- •6.8.3 Disadvantages
- •6.8.4 Final Thoughts
- •References
- •6.9 BiMICS vs. CoMICS: Our Actual Technique (Bimanual Micro Cataract Surgery vs. Coaxial Micro Cataract Surgery)
- •6.9.1 Introduction
- •6.9.2 Historical Background
- •6.9.3 BiMICS. BiManual MicroIncision Cataract Surgery
- •6.9.3.1 Introduction
- •6.9.3.2 Instrumentation
- •6.9.3.5 Phacotips
- •6.9.3.6 Capsulorhexis
- •6.9.3.7 Phaco Knives
- •6.9.3.8 The Phaco Machines
- •6.9.3.9 Phaco Pumps
- •6.9.3.10 Ultrasound Power Delivery
- •6.9.3.11 IOL Implantation
- •6.9.3.12 Astigmatism
- •6.9.4.1 Capsulorhexis
- •6.9.4.2 Phacotips
- •6.9.4.3 The Phaco Machines
- •6.9.4.4 Phaco Pumps
- •6.9.4.5 Ultrasound Power Delivery
- •6.9.4.6 Irrigation-Aspiration
- •6.9.4.7 Incision-Assisted IOL Implantation
- •6.9.5 Conclusion
- •References
- •6.10 Endophthalmitis Prevention
- •6.10.1 Antibiotic Prophylaxis
- •6.10.2 Wound Construction
- •6.10.3 Summary
- •References
- •7.1 High Myopia
- •7.2 Posterior Polar Cataract
- •7.3 Posterior Subluxed Cataracts
- •7.4 Mature Cataract with Zonular Dialysis
- •7.5 Punctured Posterior Capsule
- •7.6 Posterior Capsule Rupture
- •7.7 Pseudoexfoliation
- •7.8 Rock-Hard Nuclei
- •7.9 Switching Hands
- •7.10 Microcornea or Microphthalmos
- •7.11 Large Iridodialysis and Zonular Defects
- •7.12 Intraoperative Floppy Iris Syndrome (IFIS)
- •7.14 Iris Bombé
- •7.15 Very Shallow Anterior Chambers
- •7.16 Refractive Lens Exchange
- •7.18 Intraocular Cautery
- •7.19 Biaxial Microincision Instruments
- •References
- •7.1 MICS in Special Cases: Incomplete Capsulorhexis
- •7.1.1 Introduction
- •7.1.2 Avoiding Complications While Constructing Your Microcapsulorhexis
- •7.1.3 Avoiding Complications During Biaxial Phaco with an Incomplete Capsulorhexis
- •7.1.4 Avoiding Complications During IOL Insertion with an Incomplete Capsulorhexis
- •7.1.5 Conclusions
- •References
- •7.2 MICS in Special Cases (on CD): Vitreous Loss
- •7.2.1 Introduction
- •7.2.2 Posterior Capsule Tears and Vitreous Prolapse
- •7.2.3 Vitreous and the Epinucleus or Cortex
- •7.2.4 Different Techniques Other than Pars Plana Vitrectomy for Nuclear Loss in Vitreous
- •7.2.5 Pars Plana Vitrectomy
- •7.2.6 Zonulolysis
- •References
- •7.3 How to Deal with Very Hard and Intumescent Cataracts
- •7.3.1 Introduction
- •7.3.2 Types of Cataracts
- •7.3.3 Management of Hard Cataracts Through Biaxial Technique
- •7.3.4 Incision
- •7.3.5 Capsulorrhexis
- •7.3.6 Hydrodissection
- •7.3.8 Conclusion
- •References
- •8. IOL Types and Implantation Techniques
- •8.1 MICS Intraocular Lenses
- •8.1.1 Introduction
- •8.1.2 Lenses
- •8.1.2.2 ThinOptX MICS IOLs (ThinOptX, Abingdon, VA)
- •8.1.2.3 Akreos MI60 AO Micro Incision IOL (Bausch & Lomb, Rochester, NY)
- •8.1.2.4 IOLtech MICS lens (IOLtech, La Rochelle, France; and Carl Zeiss Meditec, Stuttgard, Germany)
- •8.1.3 Optical Quality of MICS IOLs
- •8.1.4 Conclusion
- •References
- •8.2 Implantation Techniques
- •8.2.2 Prerequisites to a Sub-2 Injection
- •8.2.3 IOLs Used for Injection Through Microincision
- •8.2.3.1 Material
- •8.2.3.2 Design
- •8.2.3.3 Optic Design
- •8.2.3.4 Haptic Design
- •8.2.3.5 Posterior Barrier (360°)
- •8.2.4 Injectors Meant for Microincision
- •8.2.4.1 Objectives of Injectors Meant for Microincision
- •8.2.4.2 Characteristics of Sub-2 Injectors
- •8.2.4.3 The Cartridges
- •Loading Chambers
- •Injection Tunnels and Cartridge Tips
- •8.2.4.4 The Plunger Tips (or plunger)
- •8.2.4.5 Pushing Systems
- •8.2.4.6 Injector Bodies
- •8.2.4.7 Principal Sub-2 Injectors
- •8.2.5 Visco Elastic Substances and Injection Through Microincision
- •8.2.6 Techniques of Sub-2 Injection
- •8.2.6.2 Incision Construction
- •8.2.6.3 Pressurization of the Anterior Chamber
- •8.2.6.4 Loading the Cartridge
- •8.2.6.5 Loading the Injector
- •8.2.6.6 Insertion of the Plunger Tip
- •8.2.6.7 Injection in the Anterior Chamber
- •8.2.6.8 Positioning the IOL in the Capsular Bag
- •8.2.6.9 Removing the VES
- •8.2.6.10 Thin Roller Injector
- •8.2.6.11 Conclusion
- •Reference
- •8.3 Special Lenses
- •8.3.1 Toric Posterior Chamber Intraocular Lenses in Cataract Surgery and Refractive Lens Exchange
- •8.3.1.1 Introduction
- •8.3.1.3 T-IOL Calculation
- •8.3.1.4 Current T-IOL Models
- •8.3.1.5 Preoperative Marking
- •8.3.1.6 Clinical Indications
- •8.3.1.7 Custom-Made Lenses
- •8.3.1.8 Conclusion for Practice
- •References
- •8.3.2 Special Lenses: MF
- •8.3.2.1 Discussion
- •8.3.2.2 Conclusion
- •8.3.2.3 Outlook
- •References
- •8.3.3 Special Lenses: Aspheric
- •References
- •8.3.4 Intraocular Lenses to Restore and Preserve Vision Following Cataract Surgery
- •8.3.4.1 Introduction
- •8.3.4.2 Why Filter Blue Light?
- •Summary
- •8.3.4.3 Importance of Blue Light to Cataract and Refractive Lens Exchange Patients
- •Summary
- •8.3.4.4 Quality of Vision with Blue Light Filtering IOLs
- •Summary
- •8.3.4.5 Clinical Experience
- •Summary
- •8.3.4.6 Unresolved Issues and Future Considerations
- •References
- •8.3.5 Microincision Intraocular Lenses: Others
- •8.3.5.1 ThinOptX®
- •8.3.5.2 Smart IOL
- •8.3.5.4 AcriTec
- •8.3.5.5 Akreos
- •8.3.5.7 Rayner
- •8.3.5.8 Injectable Polymers
- •8.3.5.9 Final Comments
- •References
- •9. Outcomes
- •9.1 Safety: MICS versus Coaxial Phaco
- •9.1.1 Introduction
- •9.1.2 Visual Outcomes
- •9.1.3 Incision Damage
- •9.1.4 Corneal Incision Burn
- •9.1.5 Corneal Changes
- •9.1.6 Infection
- •9.1.7 Summary
- •References
- •9.2 Control of Corneal Astigmatism and Aberrations
- •9.2.1 Introduction: Impacts of MICS Incision on the Outcomes of Cataract Surgery
- •9.2.2 Objective Evaluation of Corneal Incision
- •9.2.3 Control of Corneal Aberration and Astigmatism with MICS
- •9.2.4 Role of Corneal Aberrometry in Evaluating MICS Incision
- •9.2.5 Role of OCT in Evaluating MICS Incision
- •9.2.6 Our Experience in Corneal Aberrations and Astigmatism After MICS
- •9.2.7 Conclusion
- •References
- •9.3 Corneal Endothelium and Other Safety Issues
- •9.4 Incision Quality in MICS
- •9.4.1 Introduction: History of Incision Size Reduction
- •9.4.2 The Trends Towards Microincision Cataract Surgery (BMICS)
- •9.4.3 Advantages of Minimizing the Incision Size
- •9.4.4 Model for the Analysis of Corneal Incision Quality [21]
- •9.4.5 Our Protocol for Evaluation of Incision Quality in BMICS [21]
- •9.4.6 Results
- •9.4.6.1 Visual, Refractive and Biomicroscopic Outcomes
- •9.4.6.2 Incision Imaging (OCT) Outcomes
- •9.4.8 Conclusion
- •References
- •INDEX
8.3.3 Special Lenses: Aspheric |
255 |
another variable should be added to the system. In fact, Guirao et al determined that the mean surgically induced spherical aberration, following cataract extraction through a 3.5 mm clear corneal incision, with implantation of a monofocal IOL for a 6 mm pupil, calculated by ray-tracing from the corneal topography, measures 0.03
± 0.17 mm (spherical aberration mean: pre, +0.32 ± 0.12 mm, and post, +0.34 ± 0.19 mm) [35]. However, with a mean absolute error of 0.058 ± 0.056 mm for all the eyes in this study, this degree of surgically induced spherical aberration could explain the majority of inaccuracies in the results. Postoperative topography was not included as an outcome measure in the present study and remains a topic for further research.
Another limitation of this feasibility study is the absence of psychometric testing or contrast sensitivity measurements to evaluate the functional results. Analysis of the functional impact of customized selection of aspheric IOLs must eventually rely upon such data, which represent an important area for future study.
Along these lines, research in “just-noticeable differences” of refractive and wavefront errors indicates that 0.04 mm of RMS aberration should be considered as the threshold [36]. While on a population average, the benefit of aspheric IOL selection based on corneal wavefront measurements may reside below this threshold, for a specific individual, the difference may in fact be quite noticeable. Customization is particularly important for patients who have had prior keratorefractive surgery, such as LASIK. Selection of aspheric IOLs in this population remains a topic for future research.
Take Home Pearls
ßAspheric intraocular lenses offer superior mean functional vision and contrast sensitivity for
most patients.
ßSelecting the best fit aspheric IOL on the basis of corneal topography may enhance the results.
References
1.Holladay JT, Piers PA, Koranyi G, van der Mooren M, Norrby S. A new intraocular lens design to reduce spherical aberration of pseudophakic eyes. J Refract Surg 2002; 18:683–691
2.Kurz S, Krummenauer F, Thieme H, Dick HB. Contrast sensitivity after implantation of a spherical versus an aspherical intraocular lens in biaxial microincision cataract surgery. J Cataract Refract Surg 2007; 33(3):393–400
3.Tecnis Foldable Ultraviolet Light-Absorbing Posterior Chamber IOL [package insert]. Advanced Medical Optics, Santa Ana, CA, 2005
4.Packer M, Fine IH, Hoffman RS, Piers PA. Initial clinical experience with an anterior surface modified prolate intraocular lens. J Refract Surg 2002; 18:692–696
5.Mester U, Dillinger P, Anterist N. Impact of a modified optic
design on visual function: Clinical comparative study. J Cataract Refract Surg 2003; 29(4):652–660
6. Packer M, Fine IH, Hoffman RS, Piers PA. Improved functional vision with a modified prolate intraocular lens. J Cataract Refract Surg 2004; 30:986–992
7.Bellucci R, Scialdone A, Buratto L, Morselli S, Chierego C, Criscuoli A, Moretti G, Piers P. Visual acuity and contrast sensitivity comparison between Tecnis and AcrySof SA60AT
intraocular lenses: A multicenter randomized study. J Cataract Refract Surg 2005; 31(4):712–717
8.Kennis H, Huygens M, Callebaut F. Comparing the contrast sensitivity of a modified prolate anterior surface IOL and of two spherical IOLs. Bull Soc Belge Ophtalmol 2004; 294:49–58
9.Kershner RM. Retinal image contrast and functional visual performance with aspheric, silicone, and acrylic intraocular lenses: prospective evaluation. J Cataract Refract Surg 2003; 29:1684–1694
10.Ricci F, Scuderi G, Missiroli F, Regine F, Cerulli A. Low contrast visual acuity in pseudophakic patients implanted with an anterior surface modified prolate intraocular lens. Acta Ophthalmol Scand 2004; 82(6):718–722
11.Martinez Palmer A, Palacin Miranda B, Castilla Cespedes M, Comas Serrano M, Punti Badosa A. Spherical aberration influence in visual function after cataract surgery: Prospective randomized trial [in Spanish]. Arch Soc Esp Oftalmol 2005; 80(2):71–77
12.Munoz G, Albarran-Diego C, Montes-Mico R, RodriguezGalietero A, Alio JL. Spherical aberration and contrast sensitivity after cataract surgery with the Tecnis Z9000 intraocular lens. J Cataract Refract Surg 2006; 32(8):1320–1327
13.Kasper T, Buhren J, Kohnen T. Visual performance of aspherical and spherical intraocular lenses: intraindividual comparison of visual acuity, contrast sensitivity, and higherorder aberrations. J Cataract Refract Surg 2006; 32(12): 2022–2029
14.Awwad ST, Lehmann JD, McCulley JP, Bowman RW. A comparison of higher order aberrations in eyes implanted with AcrySof IQ SN60WF and AcrySof SN60AT intraocular lenses. Eur J Ophthalmol 2007; 17(3):320–326
15.Sandoval HP, Fernández de Castro LE, Vroman DT, Solomon KD. Comparison of visual outcomes, photopic contrast sensitivity, wavefront analysis, and patient satisfaction following cataract extraction and IOL implantation: aspheric vs spherical acrylic lenses. Eye 2008; 22(12):1469–1475
16.Rocha KM, Soriano ES, Chalita MR, Yamada AC, Bottos K, Bottos J, Morimoto L, Nose W. Wavefront analysis and contrast sensitivity of aspheric and spherical intraocular lenses: a randomized prospective study. Am J Ophthalmol 2006; 142(5):750–756
256 |
M. Packer et al. |
17.Rocha KM, Soriano ES, Chamon W, Chalita MR, Nosé W. Spherical aberration and depth of focus in eyes implanted with aspheric and spherical intraocular lenses: a prospective randomized study. Ophthalmology 2007; 114(11):2050–2054
18.Werner L, Olson RJ, Mamalis N. New technology IOL optics. Ophthalmol Clin North Am 2006; 19(4):469–483
19.Altmann GE, Nichamin LD, Lane SS, Pepose JS. Optical performance of 3 intraocular lens designs in the presence of decentration. J Cataract Refract Surg 2005; 31(3):574–585
20.Piers PA, Fernandez EJ, Manzanera S, Norrby S, Artal P. Adaptive optics simulation of intraocular lenses with modified spherical aberration. Invest Ophthalmol Vis Sci 2004; 45(12):4601–4610
21.Beiko G. Personalized Correction of Spherical Aberration in Cataract Surgery. In: Annual Meeting of the American Academy of Ophthalmology, Chicago, IL, 18 October 2006
22.Levy Y, Segal O, Avni I, Zadok D. Ocular higher-order aberrations in eyes with supernormal vision. Am J Ophthalmol 2005; 139(2):225–228
23.Wang L, Koch DD. Ocular higher-order aberrations in individuals screened for refractive surgery. J Cataract Refract Surg 2003; 29(10):1896–1903
24.Beiko GH, Haigis W, Steinmueller A. Distribution of corneal spherical aberration in a comprehensive ophthalmology practice and whether keratometry can predict aberration values. J Cataract Refract Surg 2007; 33(5):848–858
25.Packer M, Fine IH, Hoffman RS. Bimanual ultrasound phacoemulsification. In: Fine IH, Packer M, Hoffman RS (eds) Refractive Lens Surgery. Springer, Heidelberg, 2005, pp 193–198
26.Apple DJ, Peng Q, Visessook N, Werner L, Pandey SK, Escobar-Gomez M, Ram J, Whiteside SB, Schoderbeck R, Ready EL, Guindi A. Surgical prevention of posterior capsule opacification. Part 1: Progress in eliminating this complication of cataract surgery. J Cataract Refract Surg 2000; 26(2):180–187
27.Guyton DL, Uozato H, Wisnicki HJ. Rapid determination of intraocular lens tilt and decentration through the undilated pupil. Ophthalmology 1990; 97(10):1259–1264
28.Wu M, Li H, Cheng W. Determination of intraocular lens tilt and decentration using simple and rapid method. Yan Ke Xue Bao 1998; 14(1):13–16; 26
29.Padmanabhan P, Rao SK, Jayasree R, Chowdhry M, Roy J. Monochromatic aberrations in eyes with different intraocular lens optic designs. J Refract Surg 2006; 22(2):172–177
30.Denoyer A, Roger F, Majzoub S, Pisella PJ. [Quality of vision after cataract surgery in patients with prolate aspherical lens]. J Fr Ophtalmol 2006; 29(2):157–163
31.Bellucci R, Morselli S, Piers P. Comparison of wavefront aberrations and optical quality of eyes implanted with five different intraocular lenses. J Refract Surg 2004; 20(4):297–306
32.Caporossi A, Martone G, Casprini F, Rapisarda L. Prospective randomized study of clinical performance of 3 aspheric and 2 spherical intraocular lenses in 250 eyes. J Refract Surg 2007; 23:639–648
33.Piers PA, Weeber HA, Artal P, Norrby S. Theoretical comparison of aberration-correcting customized and aspheric intraocular lenses. J Refract Surg 2007; 23(4):374–384
34.Packer M. Tilt and decentration: Toward a new definition of tolerance. In: Fine IH (ed) Perspectives in Lens and IOL Surgery. EyeWorld 2005; 10(6):65–66
35.Guirao A, Tejedor J, Artal P. Corneal aberrations before and after small-incision cataract surgery. Invest Ophthalmol Vis Sci 2004; 45:4312–4319
36.Legras R, Chateau N, Charman WN. Assessment of justnoticeable differences for refractive errors and spherical aberration using visual simulation. Optom Vis Sci 2004; 81(9):718–728