Premier IOL choices- Earlier cataract surgery vs Femtosecond laser cataract surgery

1. Premier IOL choices
Technique & Decision Making
or earlier cataract surgery
or do we really need femtosec
laser cataract surgery
Dr. Inderjit Singh
FRCS(E)., FRCOphth., FRANZCO
Chatswood , Sydney

2. Aim of modern cataract Surgery
Royal College of Ophthalmologists

Restoration of vision
 Achievement of desired refractive
outcome
 Improvement QOL
 Ensuring safety and satisfaction
 A VA is not mentioned
 Meticulous pre-op;intra-op;post op mng

3. 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

4. Earlier Cataract Operations
(2)

Surgery should be performed for symptoms
rather than a number on a vision chart
– Influenced by a variety of cataracts

5. 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

6. Earlier Cataract Operations
(4)

Minimize future AAC glaucoma
 Improves glare and night driving
 Up to 97% of patients are achieving
UDVA/CDVA of 6/4

8. Visual Function Test- VF7
Reading signs – traffic,street,store
 Seeing steps,stairs,or curbs
 Watching TV
 Night driving
 Reading small print
 Doing fine handiwork
 Cooking


9. The Unhappy Patient
 Ocular
Co-morbidities
 Refractive surprises
 Astigmatism
 Amblyopia

10. FOCUS Autumn 2010
Pt. 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.

11. FOCUS – Autumn 2010
Ocular 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

12. 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

13. Refractive Surprise - Sources of Error
Norrby,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)

14. 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)


15. Ferrer-Blasco T,Montés-Micó R,Peixoto-de-Matos SC,GonzálezMéijome 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 1.25
 36% of patients having greater than 1.26 D

16. 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

17. TORIC IOLs- New Standard of care
Wolffsohn,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

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

19. 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.

20. 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

21. Wound assisted Un-enlarged 2.2mm Incision

22. K values and corneal topography centred
on visual axis
temporal
nasal

23. Toric IOLS
Alcon,
Zeiss- larger corrections
SN60 T2 = 0.5 D correction
SN60 T2 = 0.5 D – 1.0 D correction

24. Toric IOLs

2.2mm incision at mark
 5-5.5mm CCC
 Cohesive viscoelastic (provisc) for easy and
complete removal from behind IOL
 Precise alighnment using I/A tip
 start 10-20 shy of markings

25. Other Factors affecting postop astigIOL 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

26. Toric IOLS
(140 eyes )

Stable IOL in the bag
 After 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

27. Toric IOLs-Pre Op Prep

Accurate Ks and Axl
 Contact Lens wearers - 1-3 weeks
 Measure undisturbed corneas
 Get pt to blink often whilst measuring Ks

28. 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

29. Toric markings
Graether Toric Marker ASICO

30. Visual axis, CCC markings
visual axis
David Jory 8 marker

31. Repeatable CCC

32. REPEATABLE CCC

33. REPEATABLE CCC

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

35. Stable Effective IOL position
depends 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

36. Toric IOLS
(140 eyes )

Stable IOL in the bag
 After 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

37. Refractive cataract surgery

1.astigmatism can be corrected
 2.repeatable sized CCC = stable effective
lens position
 3.small astig neutral incision
 1 + 2 + 3 = predictable stable refrective
outcome.
 BUT WHAT ABOUT NEAR VISION ?

38. MULTIFOCAL IOLs

39. HAPPY PATIENT
Problem
1.
2.
3.
4.
5.
6.
7.
8.
9.
Astigmatism
Astigmatism - prexisting
Glasses free vision
Rapid visual /life style recovery
Refractive surprise
Changing refraction
PCO
Inflammatory consequencesCME.DME
Comorbidities
Solution
1.
2.
3.
4.
5.
6.
7.
8.
9.
2.2mm astig neutral incision
Toric IOL
Multifocal /toric IOL
Polite low energy quick phaco
Accurate biometry.optimise A
CCC over optic – stable IOL
Polish post capsule
Pre-op NSAIDS,polite low
energy phaco (Ozil phaco)
Assessment (OCT) +counselling

40. End Points for
Successful Cataract Surgery
=quality of vision

High contrast va maintained long term
Aspheric IOL
 Residual refraction defecit = 0.50 for both
SE and astig – Aspheric Toric and
Multifocal Toric