Premier IOL choices Technique & Decision Makingor earlier cataract surgery

or do we really need femtosec laser cataract surgery

Dr. Inderjit Singh

FRCS(E)., FRCOphth., FRANZCO

Chatswood , Sydney

Aim of modern cataract Surgery Royal College of Ophthalmologists

Restoration of vision Achievement of desired refractive

outcomeImprovement QOLEnsuring safety and satisfactionA VA is not mentionedMeticulous pre-op;intra-op;post op mng

Earlier Cataract Operations (1)

Outcomes in small incision is more predictable Glasses free vision-Toric and Multifocal IOLs Safer operation because of smaller incisions Meet the visual demands that patient expects Short recovery period

Earlier Cataract Operations (2)

Surgery should be performed for symptoms rather than a number on a vision chart– Influenced by a variety of cataracts

Earlier Cataract Operations (3)

Allow patients to minimise glasses wear Have the surgery at an age when you are still healthy

and active Improved vision, via cataract surgery, minimises falls.

Fractured hip aged 75, 40% survive one year. Contralateral hip fracture, in such a patient

Earlier Cataract Operations (4)

Minimize future AAC glaucoma Improves glare and night drivingUp to 97% of patients are achieving

UDVA/CDVA of 6/4

Visual Function Test- VF7

Reading signs – traffic,street,storeSeeing steps,stairs,or curbsWatching TVNight drivingReading small printDoing fine handiworkCooking

The Unhappy Patient

Ocular Co-morbidities Refractive surprises Astigmatism Amblyopia

FOCUS Autumn 2010Pt. Expectations

The success of refractive cataract surgery depends on achieving a predictable refractive outcome for defocus (spherical equivalent) and astigmatism. Refractive surprises can seriously compromise patient

satisfaction and also give rise to potential problems of anisometropia, dominance switch in which the dominant eye ends up with the weaker uncorrected vision and, above all, give rise a sense of failure in patients expecting good

uncorrected visual acuity.

FOCUS – Autumn 2010Ocular comorbidities

Small hyperopic eyes, large myopic eyes, eyes with very steep or flat corneas, shallow anterior chamber depths, history of refractive surgery, vitrectomy, corneal ectasia, peripheral corneal melt syndromes and contact lens use (when measured without an adequate contact lens holiday) are at significant risk of refractive surprises. It is important to warn these patients of the increased risk of refractive surprise as part of the informed consent process and prepare the patients for a second stage enhancement procedure

Refractive Surprise

Refractive Cataract Surgery

Restore transparency of ocular media +correct any refractive aberrations of the eye (ametropia,astigmatism)

Reduce spec dependence QOL and economic benefits

Refractive Surprise

Anisometropia Dominance switch Sense of failure in pts

expecting good uncorrected va

Refractive Surprise - Sources of ErrorNorrby,S. JCRS 34/3 March 2008

IOL power calculations- SRKT, HofferQ, Haigis,HolladayII, Post op Effective Lens position(36%) ( Optimising IOL constant

most important factor,Anstodemon,JCRS Jan 2011) Error in post op refraction(27%) AXL Measurements(17%) Pupil Size(8%) – only if there is spherical aberration Keratometry(10%)- ant curvature with keratometer,topographers;post

curvature IOL Power –very small variability,(desired outcome deviation =max

0.18D) Other Sources of error- corneal thickness,post surface

asphericity,higher order,chromatic aberrations,change in corneal power (Norrby,S JCRS 34/3 March 2008)

What about Astigmatism Pre-existing corneal astig –TORIC IOL Surgeon induced astig – astigmatic neutral

incision. Nailing +/- 0.50 D for both sphere

and cylinder is important

+1.00-2.00x90(SE=0) +0.25-0.50x90(SE=0)

Ferrer-Blasco T,Montés-Micó R,Peixoto-de-Matos SC,González-Méijome JM,Cerviño A.Prevalence of corneal astigmatism before cataract surgery.J Cataract Refract Surg.2009;35(1):70-75. N =

4540 eyes.

87% of cataract surgery patients have preoperative astigmatism

64% of patients fall within 0.50 to 1.2536% of patients having greater than 1.26 D

ASTIGMATISM (contd)

16% of all eyes had astig of 1.5D or more 46.8% WTR(minus cyl @180) , 34.3% ATR Temp clear corneal incision will reduce

astig in 34% of pts but worsen for 47% Corneal astig did not increase with age Correlations -AXL,Ks,ACD,WTW-normal

and abnormal eyes – effect on effective IOL position

TORIC IOLs- New Standard of careWolffsohn,JCRS,Effect of uncorrected astigmatism on

vision March 2011

Modest amounts of astigmatism can have major effect on vision

Effect independence – night,rain driving Quality of life, well being – reading speed Higher risks of falls Worse with WTR

1.Eliminate Surgeon Induced Astigmatism - Results of Astigmatism Studies Masket, MD

Surgeon Factor

The surgically induced astigmatic factor is usually in the range between 0.25 and 0.50 D when a 2.2- to 2.4-mm incision is used. Ideally, a surgeon should review the outcomes of one’s previous 20 or more cases, comparing preoperative keratometric measurements with postoperative readings. Routinely reexamining one’s surgically induced astigmatic factor to monitor for any changes can also be beneficial.

Astigmatism

aim for both spherical and astigmatic outcomes of ±0.5 D to avoid symptoms of ghosting and shadows.

A patient with >=0.75 D of regular corneal astigmatism and who desires spectacle independence for distance vision may be considered for a toric IOL. Evidence supports the use of toric IOLs even in patients with low levels of astigmatism

Statham M, Apel A, Stephensen D. Comparison of the AcrySof SA60 spherical intraocular lens and the AcrySof Toric SN60T3 intraocular lens outcomes in patients with low amounts of corneal astigmatism. Clin Experiment Ophthalmol. 2009;37:775–779

Wound assisted Un-enlarged 2.2mm Incision

K values and corneal topography centred on visual axis

nasaltemporal

Toric IOLSAlcon,

Zeiss- larger corrections

SN60 T2 = 0.5 D correction

SN60 T2 = 0.5 D – 1.0 D correction

Toric IOLs

2.2mm incision at mark5-5.5mm CCCCohesive viscoelastic (provisc) for easy and

complete removal from behind IOLPrecise alighnment using I/A tip start 10-20 shy of markings

Other Factors affecting postop astig-IOL Tilt and Shift

Small rhexis- hyperopic shift Post capsule debris (viscoelastic) and

fibrotic bands-myopic shift and cyl Irregular rhexis One loop in bag only

Toric IOLS(140 eyes )

Stable IOL in the bagAfter 1yr.- 100% within 10*

96% within 5*Markings can be 5* off> 10* from axis reduces effect by 1/3> 30* from axis causes increased astig

Toric IOLs-Pre Op Prep

Accurate Ks and AxlContact Lens wearers - 1-3 weeksMeasure undisturbed corneasGet pt to blink often whilst measuring Ks

Toric IOLs Pre Op

Mark 180 meridian steep meridian and incision site at Slit lamp.

Keep limbus dry Use thin fine mark –

thick pen = upto 10degrees

Toric markingsGraether Toric Marker ASICO

Visual axis, CCC markings visual axis David Jory 8 marker

Repeatable CCC

REPEATABLE CCC

REPEATABLE CCC

Scanning electron micrographsof the excised capsule disk edge produced by manualcapsulorhexisA) and laser capsulotomy(B). White arrows in B point to the microgrooves produced by the laserNJ Friedman -J Cataract Refract Surg. 2011 Jul;37

Stable Effective IOL positiondepends on

100 eyes Selected at random CCC measured at slit lamp Range of CCC size 5.0- 5.3 mm All covered optic CCC with bent cystotome(15c)

CCC covering optic edge

Toric IOLS(140 eyes )

Stable IOL in the bagAfter 1yr.- 100% within 10*

96% within 5*Markings can be 5* off> 10* from axis reduces effect by 1/3> 30* from axis causes increased astig

Refractive cataract surgery

1.astigmatism can be corrected2.repeatable sized CCC = stable effective

lens position3.small astig neutral incision1 + 2 + 3 = predictable stable refrective

outcome.BUT WHAT ABOUT NEAR VISION ?

MULTIFOCAL IOLs

HAPPY PATIENT

Problem1. Astigmatism

2. Astigmatism - prexisting

3. Glasses free vision

4. Rapid visual /life style recovery

5. Refractive surprise

6. Changing refraction

7. PCO

8. Inflammatory consequences-CME.DME

9. Comorbidities

Solution

1. 2.2mm astig neutral incision

2. Toric IOL

3. Multifocal /toric IOL

4. Polite low energy quick phaco

5. Accurate biometry.optimise A

6. CCC over optic – stable IOL

7. Polish post capsule

8. Pre-op NSAIDS,polite low energy phaco (Ozil phaco)

9. Assessment (OCT) +counselling

End Points forSuccessful Cataract Surgery

=quality of visionHigh contrast va maintained long term

Aspheric IOL Residual refraction defecit = 0.50 for both

SE and astig – Aspheric Toric and Multifocal Toric