The new Akreos MI 60 lens
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Transcript of The new Akreos MI 60 lens
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