The new Akreos MI 60 lens

Joel Pynson, MD - Director Design Engineering

Bausch & Lomb, Toulouse - France

London, September 9th 2006

Akreos material

• Hydrophilic acrylic• Made of MMA and HEMA• Hydration rate : 26%• First human implantation : July 1998• Excellent biocompatibility• Superior optic quality (machining versus

molding)• Over 1.5 millions lenses implanted

Akreos AO

• To improve the PCO rate with a full 360° barrier

• To improve the visual results with an aspheric optic

• To reduce the incision size from 3.2 mm to 2.8 mm

Spherical Aberration

Typical Spherical IOL

S.A. < 0

“Undercorrected” Proposed Aspherical IOL

S.A. = 0

Proposed Aspherical IOL

S.A. > 0

“Overcorrected”

Advantages

• Better optic quality whatever is the pupil diameter

• Optic quality not modified by lens decentration

• Suitable for any cornea, even cornea with negative spherical aberration

Next generation : Akreos MI 60

• Goals : develop a sub 2mm (MICS) IOL without jeopardising the stability of the implant inside the capsular bag.

• Design new haptics that are both slender and ensure excellent stability of the implant.

• Check the behaviour of the implant experimentally, by using a computer-generated finite element model

• Check the behaviour of the implant experimentally, by using the Miyake technique

Akreos MI60 haptic design

• 4 haptics angled at about 10°

• A rigid part near the 360° barrier and forming, together with the lens, a rigid central area

• A thinner, external flexible part

• A curved terminal part.

Akreos MI60 – ANSYS model

Akreos MI60 – Carrara model

Miyake Test

Pilot Clinical Study on Akreos Micro-incision Lens

• Single centre, one surgeon, 20 patients

• Primary outcome: corneal incision size

• Secondary outcomes:

– Visual quality: UCVA, BCVA (Logmar chart),

– Intracapsular stability: centration vs pupil, anterior-posterior displacement, PCO

• Follow up: 12 months

Injection technique 1: “cartridge in”

P=0,001 (Man Whitney test)

IN OUT

Before injection

2,11 mm (0,08) 1,77 mm (0,07)

After IOL implantation

2,22 mm (0,04) 1,86 mm (0,07)

Stretch stretch=0,11 (0,06)

stretch=0,09 (0,06)

Wilcoxon test p=0,008 p=0,007

• Standard injection technique, 10 patients

• Mean incision size: – 2.11mm before

implantation (min 2, max 2.3)

– 2.22 mm after implantation

– Stretch : 0,11 mm

• Minimal incision size– Min 2.2 mm

Injection technique 2:“cartridge out”

1,20

1,30

1,40

1,50

1,60

1,70

1,80

1,90

2,00

2,10

1 2 3 4 5 6 7 8 9 10

Patients

Inc

isio

n s

ize

(m

m)

Phaco

Before Injection

Post injection

• Wound-assisted technique, 10 patients

• ICD = incision diameter, no extra pressure during lens injection => Isobaric injection

• Mean incision size – 1,77 mm before injection

(min 1,7, max 1,9 )– 1,86 mm after injection– Stretch : 0,09 mm

• Minimal incision size– Min 1,8 mm

• Isobaric injection achieved with the Medicel Viscoglide 1.8 system

1.25 mm

Short learning curve

logMAR Visual Acuity

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80

UCVA BCVA

logM

AR

VA

PreOp (n=20)

M1 (n=19)

M3 (n=18)

M6 (n=19)

M12 (n=18)

20/20

20/2

20/4

20/10

20/6

• Gain of 6 lines of UCVA (left side) • Good predictability of refractive outcome • Good early post-op BCVA, • Stability of VA at 1 year

Stability of refraction over time

REFpreOp D15 M1 M3 M6 M12

mean -1,09 -0,61 -0,5 -0,5 -0,45 -0,4

SD 2,37 0,59 0,6 0,54 0,56 0,62

N 20 20 19 18 19 18

min -7,5 -2 -1,75 -1,75 -1,75 -1,75

max 2,75 0,5 0,5 0,5 0,5 0,75

-2

-1,5

-1

-0,5

0

0,5

1

D15 REF M1 REF M3 REF M6 REF M12 REF

Refraction in spherical equivalent

Lens Stability versus Pupil

Left to right: patient 10 at 15 days, 1 month, 3 month , 6 month and 1 year

• At 1, 3, 6 month and 1 year, minimal movements were observed.

•Y1 : 0.11mm (SD=0.088)

• Lens very stable in bag.

0,12

0,13

0,10

0,11

0,09

0,12

0,08

0,11

0,090,08

0,06

0,11

0,00

0,10

0,20

1M 3M 6M 12M

Op

tic

al

de

ce

ntr

ati

on

(m

m)

Total

Horizontal axis

Vertical axis

Posterior Capsule Opacification (n=18)

• Retro-illumination pictures were analysed with EPCO 2000 software analysis of 6mm and 3mm central area

• EPCO scores at 1-Year in line with what we are used to see with standard lenses.

EPCO score

0,03 0,04 0,030,005 0,02 0,0030

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

M3 M6 M12

6 mm area

3 mm area

Nd:Yag

n=19 n=19 n=18

Conclusions

• Akreos Micro-incision Lens has demonstrated to be safe and effective after 1-Year follow up

• It allows insertion through a 1.8mm incision • Isobaric injection reduces incision trauma• Innovative design provides excellent

intracapsular stability at 1 year• Visual acuity is excellent and stable• At 1 year , PCO rates are very low