EastwoodEye Surgery

Dr Gagan KhannahOphthalmic Surgeon

Eastwood Eye SurgeryMacquarie University Hospital

Sydney Eye Hospital

PresMed Annual Optometrist Conference10th March 2013

Femtosecond Laser Cataract Surgery – Magic or Myth?

A Balanced View!

Laser AssistedCataract Surgery

• Individual steps of laser assisted cataract surgery (LACS)– Anterior capsulotomy– Nuclear fragmentation– Corneal incisions

• Hypothetical benefits

• Discuss the current evidence base– very early days in adoption of LACS– further discussion of clinical

impression

Agenda

Does LACS:

• Improve precision and reproducibility?

• Improve safety?

• Improve refractive outcomes?

Questions

• Are the benefits statistically significant:

– Result unlikely to occur by chance– Does not mean result is important or

meaningful

• Are the benefits clinically or practically significant

• Is the benefit worth the extra time, cost and effort

Assessing evidence for new technology

• High resolution anterior segment imaging coupled to femtosecond laser

• Anterior capsulotomy

• Nuclear fragmentation

• Corneal incisions (primary, secondary and arcuate incisions)

Capabilities of LenSx laser

Anterior Capsulotomy

• Perform capsulotomy safely and completely, resistant to tearing

• Central, circular and reproducible– anteroposterior effective lens position– lateral centration– IOL calculations

• Predictably overlap IOL edge by 0.5mm

Anterior Capsulotomy

Anterior Capsulotomy

• Most striking feature of day 1 appearance

• Published evidence?

Anterior Capsulotomy

• Nagy

– 100% of anterior capsulotomies within 0.25mm vs 10% of manual

Anterior Capsulotomy

• Tackman, Friedman– less deviation

from intended diameter

– increased circularity

Anterior Capsulotomy

• Zoltan Nagy– Series of studies– Less IOL tilt and decentration– Better IOL-anterior capsule overlap– Decreased higher order aberrations

• Clinical significance?– No definite improved refractive result

(sphere, cylinder or unaided visual acuity)– Longer term studies required– Subgroup analysis required

Nuclear Fragmentation

• Effectively disassemble the nucleus

• Safety: protection of posterior capsule

• Safety: reduction in total phaco power and protection of corneal endothelium

Femtosecond nuclear fragmentation

• No reports of femtosecond laser direct damage to posterior capsule

• Offset from posterior capsule on imaging appears to be effective in preventing this

Nuclear fragmentation- safety

• Reducing need to go deeper with phaco tip may reduce risk of PC rupture

• 0.31% PC rupture rate lower than reported incidence of 0.53% - 2.7% in manual surgery

Nuclear fragmentation- safety

• Decreased total phaco energy confirmed to statistically significant level in multiple studies

• Close to 50% reduction in both total phaco energy and phaco time

• May reduce damage tocorneal endothelium

• May reduce potential forinflammation andcorneal burns

Nuclear fragmentation- safety

• Statistically significant reduction in phaco energy in all grades of cataract

• No studies yet to confirm reduction in endothelial cell loss. Further long term studies required.

• May be particularly important in patients with Fuch’s dystrophy

• Younger patients

Endothelial protection

Corneal incisions

Ability to customise reproducible, multiplanar corneal wounds shown in multiple studies

Corneal incisions

• Reproduciblewounds may allowmore consistentsurgically inducedastigmatism

• No large studiespublishedat this stage

Corneal incisions

• Endophthalmitis a rare but devastating complication

• Well constructed clear corneal wounds may reduce the risk of endophthalmitis

• Difficult to study: incidence 0.13%

• A lot of data would be required to prove a benefit in reducing endophthalmitis

Corneal incisions

Latest Results

• In this section, focus on objective current data, not on our clinical impression

• Objective data already demonstrates that LACS is no worse than manual phaco– Short learning curve– Would not have been able to say this about

move from ECCE to phaco in first 12 months– Took until 2001 for first large scale RCT

proving cost effectiveness of phaco vs ECCE

Conclusions

• New technology– experience rising very rapidly– 30,000 cases, almost all in the last 12

months

• Data demonstrating statistically significant benefit in a number of areas– at this stage relatively little definite clinically

significant data– large number of studies currently underway– longer term studies, eg endothelial cell loss

Conclusions

• Positive initial impressions, not discouraged by:– inability to immediately have clinically

significant evidence base– new complications– increases in cost

• As technology and techniques mature, history suggests:– complications decrease– equipment costs reduce with widespread

adoption– outcomes and efficiencies improve– Other technologies develop

Conclusions

EastwoodEye Surgery

Laser Refractive Cataract Surgery

Provides Image –guided, surgeon control to perform:– Anterior capsulotomy– Lens fragmentation– Corneal incisions

4 systems currently in development

EastwoodEye Surgery

Laser Refractive Cataract Surgery

Possible Advantages– Automates steps of cataract surgery– Improved corneal incisions & astigmatism

control– Improved capsulotomy for effective lens

positioning– Less phaco energy and endothelial cell loss

EastwoodEye Surgery

Laser Refractive Cataract Surgery

Disadvantages– Topical anaesthesia– Cost– Limitations

Small pupil

Corneal opacity

Dense cataract

Keratoconus

EastwoodEye Surgery

Laser Refractive Cataract Surgery

Exciting technology and future is bright

Still in its infancy and benefits unclear

Requires better safety data & research

Costs must be addressed

Secondary advances may revolutionise cataract surgery

Thank You