The Art of Micro-coaxial Lens Replacement

Con N. Moshegov

Sydney

Microincisional Phaco

Small incision clear corneal surgery is desirable because:

Causes less induced astigmatismPossibly reduces risk of endophthalmitisQuicker stabisation of final refraction Potentially better AC maintenance

Prospective evaluation of early visual and refractive effects with small clear corneal incision for cataract surgery.

Lyle WA, Jin GJC. J Cataract Refract Surg 1996; 22: 1456-60

Surgically induced astigmatismSurgically induced astigmatism

Microincisional PhacoMicroincisional Phaco

Two methods of microincision cataract surgery available:

Bimanual

Coaxial

3 groups each of 5 human cadaver eyesUnderwent simulated phaco by– Standard phaco (2.75mm)– Bimanual phaco (2 x 1.2mm)– Microcoaxial phaco (2.2mm)

Wound integrity assessed by noting aqueous leakage and India ink penetrationWound architecture examined with SEM

Microincisional PhacoMicroincisional Phaco

Spontaneous wound leakage evident in all 5 of the bimanual group, 1 of the standard group and none of the 2.2mm coaxial group

Whitening and edema of wound edge present in 4 eyes of the bimanual group and in none of the others

India ink penetrated the 1.2mm wounds of the bimanual group but not the coaxial group (India Ink particles have roughly the same size as bacteria)

Greater endothelial cell loss and compromise to Descemet’s membrane near wound in bimanual group

Microincisional PhacoMicroincisional Phaco

Why so?

Stress from instrument manipulation within an overly tight wound

Increased heat from a sleeveless tip

Microincisional PhacoMicroincisional Phaco

Other disadvantages of bimanual MICS:

CCC with conventional forceps not possible

Necessitates chopping technique

Necessitates irrigating chopper:– Restricted inflow → difficulty maintaining AC

Microincisional PhacoMicroincisional Phaco

OZil™ Torsional Technology is possible through a 2.2mm incision using ‘Ultra Sleeve’

Any single piece AcrySof IOL can now be implanted through an unenlarged 2.2mm incision

Minor alterations to usual technique required– CCC– Micro tip and Ultra sleeve– I/A– IOL implantation

Microincisional PhacoMicroincisional Phaco

• Some capsulorhexis forceps cannot be Some capsulorhexis forceps cannot be opened inside the 2.4mm (or smaller) incisionopened inside the 2.4mm (or smaller) incision

No good:• Masket forceps from Katena (K5-5084 & K5-5084a) • Kraff-Utrata forceps from Asico (AE-4394 & AE-4394a)

Good:Good:• Utrata from Katena (K5-5081 & K5-5081a) Utrata from Katena (K5-5081 & K5-5081a) • Inamura cross action from Duckworth & Kent (2-716-2R)Inamura cross action from Duckworth & Kent (2-716-2R)

• Vitreo-retinal micro-forceps not necessaryVitreo-retinal micro-forceps not necessary

0.9 mm MicroTip

0.9 mm Flared Tip

0.9 mm Tapered Tip

Optimal Tip for Micro-coaxial: 0.9 mm Mini-Flared Kelman 0.9 mm Mini-Flared Kelman®® ABS ABS®® Tips Tips

Angled design enhances OZil Angled design enhances OZil torsional movement and torsional movement and efficiencyefficiencyFlared head increases holding Flared head increases holding force and emulsification force and emulsification capacitycapacityNarrower proximal portion Narrower proximal portion permits utilization of higher permits utilization of higher vacuum and offers better vacuum and offers better surge suppressionsurge suppression

30° and 45° angulations

Irrigation/aspirationIrrigation/aspiration

Smaller bore I/A tip

Silicone tip an option

Metallic tips also available

No change in technique

IOL implantationIOL implantation

Not possible with ‘B’ cartridge

Modification of technique necessary with ‘C’ cartridge

Single handed injectors with second hand being used to provide countertraction

MONARCH® D Cartridge

Lockout Feature

33% smaller nozzle size than Monarch® C cartridge

D C

~ 33% reduction vs. ‘C’ nozzle tip

BA

D

C

Monarch III ‘D’ Cartridge & H4 (blue) Injector

Monarch II ‘C’ Cartridge & H3 (green) Injector

Very similar to the Very similar to the MonarchMonarch®® II (Green) Injector II (Green) Injector

Blue color for ease of identificationBlue color for ease of identification

Same ergonomic feelSame ergonomic feel

Same threads and lens advance rateSame threads and lens advance rate

Smaller plunger tip to accommodate the smaller Smaller plunger tip to accommodate the smaller MonarchMonarch®® D cartridge D cartridge

MONARCH® III Injector

NEW MonarchNEW Monarch®® III IOL Delivery III IOL Delivery System* System* (INTREPID(INTREPID™ Micro-coaxial System)™ Micro-coaxial System)

• Easier IOL loading vs. Monarch ‘C’ • 2.4mm ‘through-the-wound’

•Surgeon technique similar to Monarch II with ‘C’ with larger incision

• 2.2mm wound assisted•LESS stress vs. other systems

• AcrySof IQ (SN60WF) IOL = up to 27.0D

*Commercial availability January 2008

Attributes of AcrySof IOL

• Tough• No haptic damage• Slow controlled unfolding• Easy to orientate

Attributes of AcrySof IOL

• No tilting• Rotational stability• Blue filter • Well documented proof of low PCO

Attributes of AcrySof IOL

• Same platform with all variations

Toric IOL needs to be rotationally stable

As the pupil changes size, its centroid may not remain stationary relative to the limbus

Centration relative to the pupil

• With Acrysof single piece IOLs the surgeon can make an adjustment to the final position of the IOL

• Where the surgeon puts it is where it will stay!

Almost 30 million AcrySof IOL have been implanted over the last 10 yearsOne in every two foldable IOLs implanted in the World is made of AcrySof material70% of these are single pieceMajority of these are with a blue filter

Filtering Blue LightFiltering Blue Light

The AcrySof Natural lens has not been demonstrated to have any significant negative impact on colour perception, contrast sensitivity or scotopic vision

Despite theoretical concerns it has not been documented to cause a significant disruption to the circadian rhythm

No proof that filtering blue light reduces the risk of developing ARMD

Retinal Protection: FACTS

Mice exposed to blue light for 25 minutes Mice exposed to blue light for 25 minutes have photoreceptor damagehave photoreceptor damage

If an AcrySof Natural lens is interposed If an AcrySof Natural lens is interposed between them and the light source…between them and the light source…

much less damage occursmuch less damage occurs

Retinal Protection: FACTS

Surgeons have a marked supression of blue Surgeons have a marked supression of blue sensitivity after performing Argon laser PRP using sensitivity after performing Argon laser PRP using blue – green light blue – green light Lasts for several hoursLasts for several hoursIn more senior ophthalmologists this was In more senior ophthalmologists this was irreversibleirreversible

Gunduz, K and Arden, GB. Changes in colour contrast Gunduz, K and Arden, GB. Changes in colour contrast sensitivity associated with operating argon lasers. sensitivity associated with operating argon lasers.

Br. J. Ophthalmol 1989 (73), 241-6.

‘‘Every major IOL manufacturer is

working on the idea of a blue light

filtering lens’

I’ll bet…OZil™ Torsional Technology will prove to be a most popular method of phacoemulsification

Better efficiency and improved followability

Safer thermal profile

Utilized across all lens densities

Requires no change in technique

Goes well with microincisional surgery

Bimanual MICS will fall in popularity

AcrySof will maintain it’s popularity

No financial interest in any of the products No financial interest in any of the products mentioned and no gain in endorsing themmentioned and no gain in endorsing them