Case One

Patient: NC, Age 49.

Occupation: Systems Analyst, uses computer 7 hrs/day.

Hobbies: Reading, TV.

History: Currently wearing Boston Multivision GP for two years. Previously wore single-vision rigid lenses in monovision for several years. Once tried SCL's but got poor vision. Has history of dry eyes.

Ocular Health: Unremarkable except history of dry eyes.

General Health: Unremarkable. Last Exam 2+ years.

C.C.: Unhappy with near range of vision and distance vision is acceptable.

Subjective:

• OD Pl -2.75 x 175 20/20- Add + 1.75 20/20
• OS +0.75 -1.75 x 005 20/20- Add + 1.75 20/20

K's:

• OD 40.37/43.37 @ 90 D ½
• OS 40.37/42.37 @ 92 Do

Slit Lamp: Lids, Lashes, Conj. And Corneas were unremarkable except for #1 Periph epithelial punctate staining.

Lid Position: Lower lids were ½ below limbus. Upper lids were 2 mm above pupil in normal room illumination.

Pupil size: 5+ mm, OU.

Dominant Eye: OD.

Current Lenses: Boston Multivision (Back surface Aspheric Multifocal).

• OD 8.10 BC -1.00 DS 9.60 Dia. Add +1.50
• OS 8.20 BC -1.25 DS 9.60 Dia Add +1.50

Lens Performance:

• VA's:
• Dist.: 20/30.OD & 20/20-OS
• Near: 20/50 OD & 20/70-OS
• Lens position was lid attached and slightly high.

Diagnostic Fitting: Spherical base curve multifocal Dx CLs in Mandell Seamless (Front surface concentric with + 2.00 Add were utilized.

• OD 8.18 BC -0.75DS 9.8Dia/8.2OZ W/ 3.4mm Dist Zone +2.00
• OS 8.23 BC Plano 9.8Dia/8.20OZ W/3.4mm Dist Zone +2.00 Add

Lens Performance: Initial Performance was acceptable for expanded near range with 20/20 OD, OS, OU; however, distance vision fluctuated due to the high-riding position of the spherical base curve on the moderately toric corneas. Note that the previous lens was a back aspheric design (Boston Multivision).

Finial Design: A bitoric design incorporating the front surface multifocal effect was utilized as follows:

• OD 8.40 / 7.89 BC's +.25/-2.25 9.5Dia/8.0OZ 10.20/.25 SC, 11.50/.3 PC, 3.4mm Dist Zone, +2.00 Add Paragon HDS
• OS 8.39 / 7.99 BC's -0.25/-1.75 9.5Dia/8.0OZ 10.20/.25 SC, 11.50/.3 PC, 3.4mm Dist Zone, +2.00 Add Paragon HDS

Discussion: This patient performs a great deal of mid- (computer) to near-point (reading reports) tasks. The best multifocal design would be a simultaneous vision type. The design used does require good centration to allow for stable distance vision and a small amount of translation for critical near tasks. The toric design allowed this lens to perform these functions. This case also shows that astigmatic eyes usually always get better and more stable vision with GP's (Note there had been an unsuccessful attempt at fitting this patient with monovision with CIBA Torisoft SCL's!)

Case Two

Patient: LS, Age 58.

Occupation: Bookkeeper (part-time), uses computer one and one half hours per day.

Hobbies: Walk, tennis, ski, bicycle and gardening.

History: Patient has successfully worn rigid for 30 years. She is currently wearing single-vision distance lenses and wears single-vision reading spectacles over her lenses to perform mid- and near-point tasks.

Ocular Health: Unremarkable.

General Health: Uses hormone replacement medication and otherwise in excellent health. No history of allergies or dry eyes.

C.C.: Not happy with near vision and use of spectacles over contact lenses.

Subjective:

• OD -0.75 DS 20/20 Add +2.25 20/20
• OS -1.00 DS 20/20 Add +2.25 20/20

K's:

• OD 41.50 / 42.00 @90 Do
• OS 41.751. / 42.62 @88 Do

Slit Lamp: Lids, lashes, conjunctiva and corneas were unremarkable.

Lid Position: Lower lids were tangent to lower limbus and upper lids were 1 ½ mm above pupil margin in normal room illumination.

Pupil Size: Pupils are 5+mm in normal room illumination.

Dominant eye: OD.

Current Lenses:

• OD 8.04 BC -1.00 DS 9.8 Dia / 8.0 OZ Tricurve Design
• OS 7.98 BC -1.50 DS 9.8Dia / 9.80 OZ Tricurve Design

Lens Performance:

• VA's:
• Dist.: 20/20 OD, 20/25 OS
• Near: W/+2.00 : 20/20-OD,OS & OU
• Lenses appeared to be lid attached and had minimal apical clearance.

Diagnostic fitting: Patient was enrolled in a study using Blanchard Essential III High add multifocal GP's in Boston XO material.

• OD 8.00 BC -2.00DS 9.80 Dia. +2.50 Add
• OS 7.90 BC -2.00DS 9.80 Dia. +2.50 Add

Lens Performance: The initial performance appeared to be acceptable for a back aspheric design. The right lens did appear to move excessively and was changed to a 7.90 BC.

Final Design:

• OD 7.90 BC -1.75 DS 9.80 Dia +2.50 Add, Edge design was a minus carrier to stabilize lens position.
• OS 7.90 BC -1.50 9.80 Dia +2.50 Add, minus carrier edge design.
• VA's were:
• Dist.: 20/20-2, OD&OS, 20/20 OU
• Near: 20/25OD, 20/20OS, & 20/20 OU with good midrange.
• NOTE: This design utilizes both Back and Front Aspheric curves to obtain the higher add power.

Discussion: This case demonstrates how a high-add aspheric multifocal can give good vision performance and comfort. Back aspheric rigid lenses can cause corneal distortion. I always do corneal topography on all patients during fitting to check for corneal distortion caused by this design.