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