Contents
SECTION 1 PREOPERATIVE CONSIDERATIONS |
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1. |
Landmarks in LASIK Surgery |
2 |
2. |
M Vanathi, Namrata Sharma |
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Indications and Contraindications of LASIK |
7 |
|
3. |
Jeewan S Titiyal, Rakesh Ahuja, Namrata Sharma |
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Patient Counselling |
15 |
|
4. |
Namrata Sharma, Rakesh Ahuja, Rasik B Vajpayee |
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LASIK: Preoperative Assessment |
21 |
|
|
Michael S Loughnan |
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SECTION 2 EQUIPMENT AND INSTRUMENTS |
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5. |
Excimer Laser Machines |
36 |
6. |
Namrata Sharma, Rakesh Ahuja, Rasik B Vajpayee |
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Microkeratomes |
54 |
|
7. |
Rasik B Vajpayee, Namrata Sharma |
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LASIK Ancillary Instruments and Operating Environment Variables |
73 |
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|
Rakesh Ahuja, Jeewan S Titiyal |
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SECTION 3 SURGICAL TECHNIQUE |
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8. |
Presurgical Preparation and Exposure |
88 |
9. |
Prashant Bhartiya, Namrata Sharma, Rasik B Vajpayee |
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Marking the Cornea and Creation of Corneal Flap |
92 |
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|
Patrick Titzé, Aghlab N Khoury, George D Kymionis, George A Kounis, |
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10. |
Ioannis M Aslanides, Ioannis G Pallikaris |
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Laser Ablation and Flap Repositioning |
102 |
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|
Aghlab N Khoury, Patrick Titzé, George D Kymionis, Sotiris Plainis |
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11. |
Ioannis M Aslanides, Ioannis G Pallikaris |
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Postoperative Management in LASIK Surgery |
113 |
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Kent L Anderson, Ramin Salouti, Hugh R Taylor |
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SECTION 4 RESULTS AND COMPLICATIONS |
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12. |
Results of LASIK Surgery |
127 |
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Alka Rani Balasubramanya R Elankumaran S Rasik B Vajpayee |
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Alka Rani, Balasubramanya R, Elankumaran S, Rasik B Vajpayee |
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13. |
Refractive Surgery and Strabismus |
136 |
14. |
Lionel M Kowal, Ravindra R Battu |
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Intraoperative Complications |
147 |
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15. |
Gerard L Sutton, Namrata Sharma, Rasik B Vajpayee |
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Postoperative LASIK Complications |
166 |
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|
Bilal F Khan, Anh Nguyen, Samir A Melki |
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SECTION 5 RETREATMENT AFTER LASIK |
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16. |
Retreatment of Residual Refractive Errors after LASIK |
197 |
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Howard V Gimbel, EE Anderson Penno |
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SECTION 6 LASIK IN SPECIAL SITUATIONS |
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17. |
Hyperopic LASIK |
206 |
18. |
Mittanamalli S Sridhar |
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LASIK for Presbyopia |
216 |
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19. |
Amar Agarwal, Athiya Agarwal, Sunita Agarwal, Guillermo Avalos-Urzua |
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LASIK in Pediatric Eyes |
222 |
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20. |
Deepinder K.Dhaliwal |
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LASIK after Radial Keratotomy |
226 |
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21. |
Tushar Agarwal, Namrata Sharma, Rasik B Vajpayee |
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LASIK after Penetrating Keratoplasty |
234 |
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22. |
Eric D Donnenfeld, Renée Solomon |
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LASIK for Residual Errors after Previous Surgery |
255 |
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Namrata Sharma, Rakesh Ahuja, Rajesh Sinha, Rasik B Vajpayee |
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SECTION 7 RECENT ADVANCES IN LASIK |
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23. |
Topography Assisted LASIK |
264 |
24. |
Mayank S Pangtey, Namrata Sharma, Rasik B Vajpayee |
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Wavefront Guided LASIK |
270 |
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25. |
Laurence Sullivan, Namrata Sharma |
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Laser Sub-epithelial Keratomileusis (LASEK) |
283 |
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|
Dimitri T Azar, Joel Javier, Puwat Charukamnoetkanok, Elias Jarade |
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|
Hailton Oliveira, Sandeep Jain |
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Acknowledgements |
296 |
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Index |
297 |
Section 1
Preoperative Considerations
1
Landmarks in LASIK Surgery
M Vanathi, Namrata Sharma
The history of modern refractive surgery dates back to 1949 when Jose Ignacio Barraquer (Fig. 1.1) proposed the surgical modification of the refractive status of the eye by changing the radius of curvature of the anterior corneal surface1–4. He refined his ideas of performing lamellar keratoplasty for refractive purposes to correct spherical myopia. In 1958 Barraquer experimented on performing a free hand lamellar dissection of the corneal stroma to create a lamellar corneal disc and then attempted a refractive cut by removing stromal tissue from the bed (keratomileusis in situ) or the stromal surface of the corneal disc.1 He dissected the lamella to about half the thickness with the use of a corneal dissector or Paufique knife. He then considered freezing the lamellar corneal disc and used the cryolathe to modify the corneal disc. In the same year, he performed the first resection in situ using a prototype keratome with cutting angle of zero degree.
In 1962, Barraquer used the more accurate microkeratome and also invented the suction ring, dovetail guides between rings, applanation tonometer and first intraoperative keratoscope.
Krumeich, Swinger and Barraquer developed a new instrument in the early 1980s called the BKS
Figure 1.1 Jose Ignacio Barraquer
1000 to perform a non-freeze refractive cut (nonfreeze or BKS technique)5. In the late 1980s, Luis Ruiz developed an automated microkeratome and reported that the refractive effect of stromal resection can be altered by varying its diameter and depth. The development of this microkeratome was a major advancement in the field of lamellar
Landmarks in LASIK surgery 3
refractive surgery and the surgery came to be known as Automated Lamellar Keratoplasty [ALK]. This microkeratome rendered a much smoother stromal bed due to the controlled speed of the advancement of the keratome head and the very high speed of oscillation of the blade. However, ALK had inherent complications such as lost or displaced caps, irregular astigmatism and was not a very predictable procedure. Furthermore, the technique of ALK had a long learning curve and required considerable surgical skill and experience.
Trokel (Fig. 1.2) and Srivinivasan6 in 1983 suggested the first corneal application of the excimer laser and in 1988 the first surgical applications in the form of photorefractive keratectomy were performed by McDonald and Kaufman.7
Figure 1.2. Stephen Trokel
In 1989, Lucio Buratto 8,9 presented the technique of intrastromal keratomileusis using the excimer laser or photokeratomileusis (Fig. 1.3). He performed the refractive cut with laser ablation on either the free lamellar corneal disc (cap) or in situ ablation (excimer laser intrastromal keratomileusis [ELISK]
Figure 1.3. Lucio Buratto
Step by step LASIK surgery 4
Figure 1.4. Ioannis G Pallikaris
on the exposed stromal bed or cap). The keratomileusis is simple and safe when the ablation is performed on the cap because the mechanical fixation of the corneal disc is not required.
Pallikaris and his colleagues10 in 1990, made the next major advancement in the field of LASIK surgery when they introduced the hinge technique for LASIK, by using a flap with a nasal hinge instead of a free flap (Fig. 1.4). The tissue flap is lifted and an in situ refractive procedure on the underlying stroma is performed. This variation in the technique makes keratomileusis faster and simpler.
Buratto in 1996 started the down-up LASIK11 with a vertical cut from below upwards resulting in a superior hinge. The use of Hansatome (Baush and Lomb Surgicals, Claremont, CA) to create superior hinges allowed this technique to be widely used.
Relasik as an enhancement procedure for residual myopia was first reported by Perez et al.12 In the initial studies reablation was done on the bed. However, more recently, reablation on the cap has also been advocated.13
The advent of epithelial LASIK or laser assisted subepithelial keratomileusis (LASEK) by Massimo Camellin in 1999, further broadened the indications of excimer laser surgery (Fig. 1.5). This enabled performance of laser ablation for relatively thin corneas with higher myopic refractive errors.14 LASEK is a relatively new refractive surgical techni-
Figure 1.5. Massimo Camellin
Landmarks in LASIK surgery 5
que that combines the advantages of laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). LASEK may also prove to be superior to LASIK in customized ablations.
A number of major advancements have taken place in excimer laser machines in form of custom laser ablations15 and wavefront guided custom ablations.16 Methods of detection of wavefront aberration or aberrometry was an important discovery which laid the foundation of the future customized ablations. Based on the interferometry, Hartmann17 and Tschering18 constructed and described an apparatus by the name of “aberroscope” from a grid superimposed on a 5 diopter spherical lens. Twenty years later this aberroscope was used to investigate and characterize monochromatic aberrations and this study also introduced the concept of Zernicke polynomials.19 More recently, Webb and colleagues implemented a method which computes the wave aberrations and reduces it to Zernicke polynomials.20
Hartmann Shack wavefront sensor, a method initiated in the astronomy to analyze the aberrations of the atmosphere above a telescope in real time was adapted by Bille and Liang to image the human fundus by removing the aberrations of the eye with a definable mean.21 Josef Bille from Heidelberg, Germany is the father of wavefront technology. Theo Seiler is credited with the first wave front guided LASIK in 1999.
LASIK: IMPORTANT MILESTONES
1958 |
- Keratomileusis |
- JI Barraquer |
1962 |
- Manual Microkeratome |
- JI Barraquer |
1977 |
- First Keratomileusis in USA |
- JI Troutoan |
1980–83 |
- BKS technique |
- JH Krumeich |
1983 |
- Corneal application of Excimer laser |
- SL Trokel |
1983–86 |
- Keratomileusis in situ |
- L Ruiz |
1988 |
- First successful PRK |
- MB McDonald |
1989 |
- LASIK in normal human eye |
- L Buratto |
1990 |
- Hinge technique in LASIK |
- IG Pallikaris |
1996 |
- Down-up LASIK |
- L Buratto |
1999 |
- Relasik |
- JI Perez-Santoja |
1999 |
- LASEK |
- M Camellin |
1999 |
- Wavefront Technology |
- Josef Bille |
1999 |
- Wave front guided LASIK |
- Theo Seiler |
2002 |
- Relasik-undersurface ablation of flap |
- MJ Maldonado |
REFERENCES
1. Barraquer JI. Basis of refractive keratoplasty. An Med Espec 1965; 51:66–82.
Step by step LASIK surgery 6
2.Barraquer JI. Queratomileusis para la correction de la miopia. Arch Soc Am Optom 1964; 5:27– 41.
3.Barraquer JI. Keratomileusis. Int Surg 1967; 48:103–17.
4.Barraquer JI. Keratomileusis and Keratophakia. In Reycroft PV (Ed): Corneoplastic surgery: Proceedings of the second International Corneoplastic Conference. Pergamon Press: New York. 1969; 409–63.
5.Krumeich JH, Swinger CA. Nonfreeze epikeratophakia for the correction of myopia. Am J Ophthalmol 1987; 103:397–403.
6.Trokel SL, Srinivasan R, Braren B. Excimer laser surgery of the cornea. Am J Ophthalmol 1983; 96:710–15.
7.McDonald MB, Beuerman R, Falzoni W, Rivera L, Kaufman HE. Refractive surgery with the excimer laser. Am J Ophthalmol 1987; 103(3 Pt 2):469.
8.Buratto L, Brint S, Ferrari M. keratomileusis. In LASIK Principles and Techniques. Slack Incorporated. Thorofare NJ.
9.Buratto L, Ferrari M. Excimer laser intrastromal keratomileusis: Case reports. J Cataract Refract Surg 1992; 18:3741.
10.Pallikaris IG, Papatzanaki ME, Stathi EZ, Frenschock O, Georgiadis A. Laser in situ keratomileusis. Lasers Surg Med 1990; 10:463–68.
11.Buratto L. Down-up LASIK with the new Chiron Microkeratome; Milano, Italy 1997.
12.Perez-Santonja JJ, Ayala MJ, Sakla HF, Ruiz-Moreno JM, Alio JL. Retreatment after laser in situ keratomileusis. Ophthalmology 1999;106:21–28.
13.Maldonado MJ. Undersurface ablation of the flap for laser in situ keratomileusis retreatment. Ophthalmol 2002; 109:1453–64.
14.Michela Cimberle. LASEK has more than 1 year of successful experience. Ocular Surg News 2000.
15.Tamayo Fernandez GE, Serrano MG. Early clinical experience using custom excimer laser ablations to treat irregular astigmatism. J Cataract Refract Surg 2000; 26(10): 1442–50.
16.Highlights of the 1 st International Congress of Wavefront Sensing and Aberration-free Refractive Correction. J Refract Surg 2001; 17(5):S566–72.
17.Hartmann J. Bemerkungen ueber den Bau und die Justirung von Spektrographen. Zeitschrift fuer Instrumentenkunde. 1900; 20:47.
18.Tscherning M. Die monochromatischen Aberrationen des menschlichen Auges. Z Psychol Physiol Sinn 1894; 6:456–71.
19.Howland HC, Howland B. A subjective method for the measurement of monochromatic aberrations of the eye. J Opt Soc Am 1977; 67(11):1508–18.
20.He JC, Marcos S, Webb RH, Burns SA. Measurement of the wave-front aberration of the eye by a fast psychophysical procedure. J Opt Soc Am A Opt Image Sci Vis 1998; 15(9):2449–56.
21.Miller DT, Williams DR, Morris GM, Liang J. Images of cone photoreceptors in the living human eye. Vision Res 1996; 36(8):1067–79.