Post on 14-Feb-2017
transcript
THE NEW ERA OF CONTACTLENS FITTING?
VINCENT MOLKENBOER
OPTOMETRIST
HOW DID WE DO IT?
HOW DID WE DO IT?
• MEAN-K
• DEPENDING ON THE TYPE OF LENS +0.8 / +1.0 MM
• MULTIPLE BCR CHOICES
• MULTIPLE DIAMETERS
DID WE FORGET HOW TO FIT?
• INTRODUCTION OF DISPOSABLE HYDROGEL CONTACTLENSES ( 90’S)
• MULTIPLE BCR CHOICES
• SINGLE DIAMETER
DID WE FORGET HOW TO FIT?
• INTRODUCTION OF SILICONE HYDROGEL CONTACTLENSES (1998)
• FIRST GENERATION: 2 BCR CHOICES, 1 DIAMETER
• SECOND AND THIRD; 1 BCR , 1 DIAMETER
(RE)INVENTING CONTACTLENS FITTING?
AXIAAL VS. TANGENTIAAL
• AXIAL = IN RELATION TO THE OPTICAL AX
• TANGENTIAL = PERPENDICULAR ON THE MEASURED PART OF THE CORNEA
AXIAL
TANGENTIAL
CONTACTLENSES & CORNEAL TOPOGRAPHY
• WAT ZIEN WE?
AXIAL
TANGENTIAL
1 WEEK
2 WEEKS
1 MONTH
3 MONTHS
6 MONTHS
SOFT CONTACTLENSES & CORNEAL CHANGES
• WAT ZIEN WE NIET?
MODULUS & DESIGN/THICKNESS
Data beschikbaar gesteld door Alcon
MODULUS: 1.2 MPA VS. 0.72 MPA
TYPE: TORIC LOTRAFILCON B VS. MULTI LOTRAFILCON B
MATERIAL: COMFILCON A VS. OMAFILCON A
DESIGN: BI-CURVE VS. ASFERIC
RESULTATEN
Eef van der Worp, Eye & Contact Lens Dec 2014 – Volume 37
OC-SAG vs CL-SAG
Vincent
Molkenboer
OC-SAG vs CL-SAG
OC-SAG vs CL-SAG
Eef van der Worp Vincent Molkenboer Global Contact 1/2015 – Volume 68
EAGLET EYE
SAGGITAL DIFFERENCES
Overview of lowest (left) to highest CL-SAG of all lenses (spherical and toric) in the minus group ( microns)
Sf(-)
OPTOCRAFT
Air Optix 8.6/14.2
Biofinity 8.6/14.0
Oasys 8.4/14.0
Oasys 8.8/14.0
Purevision
8.3/14.0
Purevision
8.6/14.0
Air Optix Ast
8.7/14.5
Biofinity Toric
8.7/14.5
Oasys Ast
8.6/14.5
Purevision Toric
8.7/14.0 Air Optix 8.6
14.2 -45 51 -225 87 -170 155 187 275 -184 Biofinity 8.6
14.0 45 96 -180 132 -125 200 232 320 -139 Oasys 8.4
14.0 -51 -96 -276 36 -221 104 136 224 -235 Oasys 8.8
14.0 225 180 276 311 55 380 411 499 41 Purevision 8.3
14.0 87 -132 -36 -311 -256 69 100 188 -270 Purevision 8.6
14.0 170 125 221 -55 256 325 356 444 -14
Air Optix Ast 8.7 14.5 -155 -200 -104 -380 -69 -325 32 120 -339
Biofinity Toric 8.7 14.5 -187 -232 -136 -411 -100 -356 -32 88 -370
Oasys Ast 8.6 14.5 -275 -320 -224 -499 -188 -444 -120 -88 -458
Purevision Toric 8.7 14.0 184 139 235 -41 270 14 339 370 458
Eef van der Worp, Christian Mertz Eye & Contact Lens 2015 – Volume 38
Sagittal Height Differences of Frequent Replacement Silicone Hydrogel Contact Lenses
Eef van der Worp, Cristian Mertz
HEIGHT
CL-SAG: 3529
OC-SAG 3613μ
HEIGHT
8.10
OC-SAG 3613μ
CL-SAG: 3529
OC-SAG 3667μ
CL-SAG: 3858 + 200μ (from OC-SAG)
14.0 CL-SAG: 4091
OC-SAG 3667μ
+ 400μ (from OC-SAG)
OC-SAG vs CL-SAG
Graeme Young Optometry & Vision Science July 2014 - Volume 91
This mathematical model shows that ‘lens edge strain’ in a normal eye, with a typical (8.6 - 14.2mm) lens this could be as much as 2.7%
strain - but for the same lens on a cornea and/or ocular surface that is flat this would
result in a tight fit showing 8.5% strain.
This mathematical model shows that ‘lens edge strain’ in a normal eye, with a typical (8.6 - 14.2mm) lens this could be as much as 2.7%
strain - but for the same lens on a cornea and/or ocular surface that is flat this would
result in a tight fit showing 8.5% strain.
CUSTOM MADE
Tsag-Nsag = 0.81 mm CENTRATION
Tsag-Nsag = 0.81 mm CENTRATION
CONCLUSION
• WE NEED MORE INFORMATION ABOUT THE EFFECTS OF CONTACTLENSES ON THE CORNEA
• WE NEED BETTER OR OTHER DESIGNS TO BE SUCCEFULL IN MYOPIA CONTROL AND MULTIFOCAL CONTACTLENSES
• MAYBE WE NEED DIFFERENT DESIGNS FOR ALL SOFT CONTACTLENSES