Soft CL Multifocals Design and Fitting. Soft Multifocal Lens Designs. Issues Surrounding Multifocals. Blur Interpretation. Simultaneous Vision Designs

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1 Soft CL Multifocals Design and Fitting Mark Andre, FAAO Associate Professor of Optometry Pacific University Mark Andre, FAAO is affiliated with CooperVision, as a consultant. Issues Surrounding Multifocals Success rates Chair time Diminished visual acuities Dryness Lens cost Practitioner s confidence Soft Multifocal Lens Designs Aspheric Center Near Design Multizone Design Aspheric Center Distance Design Simultaneous Vision Designs Blur Interpretation 1

2 Looks can be deceiving! What if we could see the complexity of the optical design? Aspheric Center Near Designs Corneal Mapping over CL Aspheric Center Near Design (High Add) Case History 65 year old patient wearing Aspheric Center Near design CLs Complains of poor visual acuity with new higher add lenses Unable to improve with over-refraction Possible Causes Increase in add power effects distance VA Pupil Size Aspheric Center Near Designs Low Add High Add 2

3 Pupil Size and Age Age Daylight Nighttime (Years) Diameter Diameter mm Pupil N 4.5 mm Pupil 5.6 mm Pupil Case History 47 year old patient wearing Aspheric Center Near design multifocals complains of poor vision Rx: with a Low Add No improvement with over-refraction Possible Causes Contact lens optics not aligned with patients line of sight Decentered or high riding lens Angle Lambda and Multifocals Fovea is temporal to the posterior pole. Visual axis passes through the lens at an angle of 3 to 11 degrees. X Line of Sight Centered Optics Line of Sight 3

4 Anterior Aspheric Optics Difference Display over CL Aspheric Center Near Design Radial Astigmatism Horizontal Coma Spherical Aberration Topography over a High Riding Aspheric Multifocal Aspheric Center Distance Designs 4.0 mm Pupil 3.5 mm Case History 57 year old patient wearing Aspheric Center Distance design multifocals Rx: with a High Add Complains of poor near vision Possible Cause Pupil size 4

5 Pupil Size and Age 2.6 mm Pupil 5.6 mm Pupil Age Daylight Nighttime (Years) Diameter Diameter D D. Low Add 0mm 1mm 2mm 3mm 4mm 5mm 6mm Age Pupil Diameter to 3.5 mm 2.6 mm Pupil 5.6 mm Pupil Concentric or Multi-Zone Multifocals Available in center/near or center/distance D D. Low Add 0mm 1mm 2mm 3mm 4mm 5mm 6mm High Add 0mm 1mm 2mm 3mm 4mm 5mm 6mm Distance Near Distance Distance Distance Center Near Near Distance Near Near Near Center Distance Concentric Ring Center Distance Designs Topography over CL Concentric Rings Design (Center Distance) 5

6 Case History 46 year old patient wearing Concentric Ring design multifocals Rx: with a add Complains of haloes, glare and ghosting The Effect of Sagittal Height 10.2 mm 13.0 mm Possible Cause Pupil size Depth of anterior chamber The Effect of Sagittal Height 10.2 mm 13.0 mm Difference Display over CL Concentric Ring Design (Center Distance) Difference Display over CL Concentric Rings Design (Center Distance) Multi-zone Center Distance Designs 6

7 Topography over CL Multi-zone Center Distance Design Multi-zone Center Near Designs Difference Display over Center Near Multi-zone Design (+2.50 Add) Balanced Progressive Technology Center Distance Design Center Near Design Case History 64 year old patient wearing Multi-zone design multifocals OD with a Add D Lens OS with a Add N Lens Complains of poor distance vision Corneal Mapping over high riding Multi-zone D Lens (+2.50 Add) Possible Cause De-centered or high riding lens Poor distance acuity in N lens 7

8 Difference Display (+2.50 Add) Multi-Zone Design Radial Astigmatism Vertical Coma Spherical Aberration Corneal Mapping over centered Multi-zone D Lens (+2.50 Add) Difference Display (+2.50 Add) High Riding Lens Centered Lens 8.7 Base Curve 8.4 Base Curve Multi-zone Multifocal Toric The lens is a double slab off back toric with markings at 3 & 9 o clock 8

9 Translating Soft Contact Lenses #1 Do not confuse equilibration, with adaptation. Equilibration takes minutes, while adaptation sometimes requires hours, or even days. #2 Do not provide more add power than necessary. Prescribe the add power as you would for flat top or executive bifocals. #3 Use a cell phone to assess near functional vision. Immediate feedback Everyday tasks that are important to the patient #4 Be suspicious of unexpected overrefractions. #5 Don t ignore the astigmatic error. Check for poor fitting or decentered lenses. Line of sight issues. 9

10 #6 Reach final Rx in 1-2 visits. Make small change in lens Rx Additional visits may not improve vision Identify cause of vision issues Thank You 10