Femtosecond Laser - Principles and Application in Ophthalmology

1.Introduction and historical overview18
1.1.Some milestones in the development of femtosecond lasers and their applications18
1.2.References19
2.Physical principles of the generation and amplification of ultrashort laser pulses22
2.1.Laser process and laser resonator22
2.2.Bandwidth of laser radiation22
2.3.Laser resonator22
2.4.Mode synchronisation (mode-locking)23
2.5.Amplification of fs pulses24
2.6.References26
3.Femtosecond lasers in ophthalmology: laser-tissue interaction, multiphoton imaging, biomechanical modelling28
3.1.Introduction28
3.2.Laser-tissue interaction28
3.3.Multiphoton imaging30
3.4.Biomechanical modelling34
3.5.Conclusions and outlook36
3.6.References37
4.Clinical application40
4.1.Intrastromal femtosecond laser incisions40
4.1.1.Introduction40
4.1.2.Implantation of ICRS and effects on keratoconus40
4.1.3.Mechanical tunnel incisions and implantation of ICRS40
4.1.4.Femtosecond laser-controlled tunnel incisions before ICRS implantation41
4.1.5.Application41
4.1.6.Surgery42
4.1.7.Case report: Ex- and reimplantation of ICRS in keratoconus with fs laser support44
4.1.8.Long-term postoperative results45
4.1.9.Summary46
4.1.10.References46
4.2.Perforating keratoplasties with the femtosecond laser47
4.2.1.Introduction47
4.2.2.High degree of flexibility in the pKPL using the femtosecond laser47
4.2.3.Application48
4.2.4.Surgery50
4.2.5.Results50
4.2.6.Case reports51
4.2.7.Summary53
4.2.8.References53
4.3.Penetrating keratoplasty using the TECHNOLAS femtosecond laser: The Heidelberg Experience54
4.3.1.Introduction54
4.3.2.Studies on penetrating keratoplasty with the TECHNOLAS fs laser54
4.3.2.1.Clinical experiences54
4.3.2.2.Histopathology of corneal buttons56
4.3.2.3.Postoperative endothelial cell count57
4.3.3.Results of penetrating keratoplasty by different fs laser cut designs58
4.3.4.References59
4.4.Anterior lamellar keratoplasties with the femtosecond laser60
4.4.1.Introduction60
4.4.2.Application60
4.4.3.Surgery60
4.4.4.Results61
4.4.5.Case reports61
4.4.6.Summary63
4.4.7.References63
4.5.Endothelial grafts or posterior lamellar keratoplasties with the femtosecond laser63
4.5.1.Introduction63
4.5.2.Application63
4.5.3.Surgery65
4.5.4.Results65
4.5.5.Case reports65
4.5.6.Summary67
4.5.7.References67
4.6.Astigmatic keratotomies with the femtosecond laser67
4.6.1.Introduction67
4.6.2.Indications68
4.6.3.Diagnostic analysis68
4.6.4.Application68
4.6.5.Surgery69
4.6.6.Case reports69
4.6.7.References72
5.Refractive surgery with the femtosecond laser76
5.1.Flap dissection during LASIK (Femto-LASIK)76
5.1.1.Background 76
5.1.2.Hinge position76
5.1.3.Hinge length77
5.1.4.Flap thickness77
5.1.5.Geometry of the angle of incision (side cut)77
5.1.6.Flap diameter77
5.1.7.Visual control of flap dissection78
5.1.8.Application of flap preparation78
5.1.9.Surgery79
5.1.10.Summary80
5.1.11.Studies on flap cutting with the TECHNOLAS fs laser: The Heidelberg Experience80
5.1.12.References81
5.2.Intrastromal refractive correction with the femtosecond laser82
5.2.1.Refractive surgery – an introduction82
5.2.2.The INTRACOR procedure83
5.2.3.CE approval study for INTRACOR83
5.2.4.Patient selection for INTRACOR85
5.2.5.References86
6.Prospects for femtosecond laser in ophthalmology88
6.1.Introduction88
6.2.Femtosecond technology – where to now?88
6.3.Clinical prospects89
6.4.References91
Index94