Journal clubJournal club

Irina CozmaIrina Cozma

On behalf of David H Hughes’ On behalf of David H Hughes’ teamteam

Royal Gwent HospitalRoyal Gwent Hospital

VasavadaVasavada AR, AR, RajRaj SM. SM. Anterior capsule relationship Anterior capsule relationship

of the AcrySof intraocular of the AcrySof intraocular lens optic and posterior lens optic and posterior capsule opacification: a capsule opacification: a prospective randomized prospective randomized

clinical trial.clinical trial...

Ophthalmology. 2004 Ophthalmology. 2004 May;111(5):886-94May;111(5):886-94

PCOPCO

• Common complication of cataract Common complication of cataract surgery with IOL implantationsurgery with IOL implantation

• Meta-analysis 1998Meta-analysis 1998

• Schaumberg DA et al A systematic Schaumberg DA et al A systematic overview of the incidence of PCO.overview of the incidence of PCO.Ophthalmology. 1998 Ophthalmology. 1998 Jul;105(7):1213-21. Jul;105(7):1213-21.

Incidence of PCO with AcrySof Incidence of PCO with AcrySof IOL IOL

• Is very lowIs very low

• Hydrophobic acrylic AcrySof® leads to Hydrophobic acrylic AcrySof® leads to the lowest incidence of PCO.3 A study the lowest incidence of PCO.3 A study with a 3-year follow-up showed that with a 3-year follow-up showed that hydrophobic acrylic IOLs yielded the hydrophobic acrylic IOLs yielded the lowest percentage of PCO (10%) lowest percentage of PCO (10%) followed by silicone (40%) and followed by silicone (40%) and poly(methyl methacrylate) (PMMA) poly(methyl methacrylate) (PMMA) (56%) lenses.2 (56%) lenses.2

• Sharp truncated optic edge combined with Sharp truncated optic edge combined with total cover of the optic by the anterior total cover of the optic by the anterior capsule is crucial to blocking the migration capsule is crucial to blocking the migration of lens epithelial cells. of lens epithelial cells.

• There are 2 conflicting theories on the There are 2 conflicting theories on the mechanism. Nishi and coauthors22 mechanism. Nishi and coauthors22 postulate that cell contact inhibition is postulate that cell contact inhibition is responsible for reduced PCO with square-responsible for reduced PCO with square-edged IOLs, while Boyce and coauthors23 edged IOLs, while Boyce and coauthors23 suggest the phenomenon may be caused suggest the phenomenon may be caused by a mechanical pressure barrier effect at by a mechanical pressure barrier effect at the sharp optic edge. the sharp optic edge.

• It also seems that overall IOL size is It also seems that overall IOL size is important in preventing PCO, with a important in preventing PCO, with a 6.0 mm optic leading to less PCO 6.0 mm optic leading to less PCO than a 5.5 mm optic 2 years after than a 5.5 mm optic 2 years after surgery.24 The above factors surgery.24 The above factors undoubtedly influenced the low undoubtedly influenced the low incidence and severity of PCO with incidence and severity of PCO with both IOLs in our study.both IOLs in our study.

Incidence of PCOIncidence of PCO

• 11.8% - 1 year11.8% - 1 year

• 20.75% – 2 years20.75% – 2 years

• 28.55% - 3 years 28.55% - 3 years

What is the study What is the study about?about?• Means and approaches to prevent or Means and approaches to prevent or

delay PCOdelay PCO

• Not looking at :Not looking at :

• How to quantify PCO most common How to quantify PCO most common used POCOMAN used POCOMAN

• http://www.ph.kcl.ac.uk/http://www.ph.kcl.ac.uk/POCOMAN.html POCOMAN.html

• Ocular or systemic factorsOcular or systemic factors

Clinical approaches to PCO Clinical approaches to PCO preventionprevention• Non IOL relatedNon IOL related• SurgicalSurgical• Anterior CCC sizeAnterior CCC size• Posterior CCCPosterior CCC• Capsule polishingCapsule polishing• Cortical clean upCortical clean up• MechanicalMechanical• Capsular tension ringCapsular tension ring• ChemicalChemical• HeparinHeparin

• IOL relatedIOL related• SurgicalSurgical• Placement site of IOLPlacement site of IOL• MechanicalMechanical• IOL optic edgeIOL optic edge• ChemicalChemical• Surface coatingSurface coating

The studyThe study

• Prospective randomised controlledProspective randomised controlled

• Primary end point:Primary end point:

• To evaluate the relationship of the anterior To evaluate the relationship of the anterior capsule and AcrySof MA 30 IOL and its capsule and AcrySof MA 30 IOL and its impact on the development of central PCOimpact on the development of central PCO

• Secondary end point:Secondary end point:

• Incidence of PCO in the 3 zones of the Incidence of PCO in the 3 zones of the capsule capsule

Inclusion criteriaInclusion criteria

• 202 consecutive patients with senile 202 consecutive patients with senile cataracts over 50 yr old operated on over cataracts over 50 yr old operated on over 6/12 in India 6/12 in India

• One surgeonOne surgeon

• Same cataract techniqueSame cataract technique

• Ethics committee approvedEthics committee approved

• Informed consentInformed consent

• Pupil dilatation more than 7mmPupil dilatation more than 7mm

• Hypertensive includedHypertensive included

Exclusion criteriaExclusion criteria

• Co-morbidity or previous intraocular Co-morbidity or previous intraocular surgerysurgery

• BlackBlack

• On topical or systemic NSAIDS or On topical or systemic NSAIDS or steroidssteroids

MethodMethod

• Same surgical techniqueSame surgical technique• Topical anestheticTopical anesthetic• Temporal clear corneal incisionTemporal clear corneal incision• Acrysoft MA30 5.5mm optic and Acrysoft MA30 5.5mm optic and

12.5mm diameter in the bag12.5mm diameter in the bag• After IOL implanted and before After IOL implanted and before

viscoelastic removedviscoelastic removed• Randomization: envelope Randomization: envelope

Randomization groupsRandomization groups

• 1. Anterior capsule covering 1. Anterior capsule covering completely the edge of IOL completely the edge of IOL

• 2.Anterior capsule totally off the IOL 2.Anterior capsule totally off the IOL edgeedge

• 3. Anterior capsule partially covered 3. Anterior capsule partially covered the edge of IOL the edge of IOL

AssessmentAssessment

• 1/521/52

• 1/121/12

• 6/126/12

• 12/12.12/12.

• 18 patients excluded as no f/u(6,4,6).18 patients excluded as no f/u(6,4,6).

• Single observer.Single observer.

• No eye required Yag laser at 3 years.No eye required Yag laser at 3 years.

Does this research add to Does this research add to literature in any way?literature in any way?

• Will the result add information to a Will the result add information to a meta-analysis?meta-analysis?

• Is there sufficient doubt in the mind Is there sufficient doubt in the mind of the reader to make new evidence of the reader to make new evidence desirable even when not scientifically desirable even when not scientifically necessary? necessary?

. Incidence of Posterior Capsule Opacification in the Peripheral Zone of the Posterior Capsule

                                                                                                                     

.

Incidence of PCOn in the Midperipheral Zone of Posterior Capsule

                                                                                                                                                                                                                                                                                                                                                                        

Incidence of PCO in the Central Zone of the Posterior Capsule

                                                                                                                     

ConclusionConclusion

• When using Acrysoft mode MA30 the relationship When using Acrysoft mode MA30 the relationship of the AC and the IOL is not a factor that relates of the AC and the IOL is not a factor that relates to the development of central PCO at 3 years.to the development of central PCO at 3 years.

• Confirms suggestion of retrospective study that at Confirms suggestion of retrospective study that at 3 years overlap of the anterior capsule is more 3 years overlap of the anterior capsule is more critical with SI40 than with AcrySof 3-piece. critical with SI40 than with AcrySof 3-piece.

• Peripheral opacification was slow and similar Peripheral opacification was slow and similar between the groups.between the groups.

• Midperipheral opacification was present in 24.2% Midperipheral opacification was present in 24.2% in group 1, 16% in group 2 and 20.65 9n group 3. in group 1, 16% in group 2 and 20.65 9n group 3.

Power and limitationsPower and limitations

• Power close to Power close to 80%.80%.

• Degree of PCO has Degree of PCO has not been assessed, not been assessed, only presence or only presence or absence.absence.

Take home messageTake home message

• A total cover of the optic when using A total cover of the optic when using AcrySof MA30 does not seem to be AcrySof MA30 does not seem to be compulsory.compulsory.