Journal Club

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Journal Club

  1. 1. Journal club Irina Cozma On behalf of David H Hughes’ team Royal Gwent Hospital
  2. 2. Vasavada AR, Raj SM. Anterior capsule relationship of the AcrySof intraocular lens optic and posterior capsule opacification: a prospective randomized clinical trial. . Ophthalmology. 2004 May;111(5):886-94
  3. 3. PCO <ul><li>Common complication of cataract surgery with IOL implantation </li></ul><ul><li>Meta-analysis 1998 </li></ul><ul><li>Schaumberg DA et al A systematic overview of the incidence of PCO. Ophthalmology. 1998 Jul;105(7):1213-21. </li></ul>
  4. 4. Incidence of PCO with AcrySof IOL <ul><li>Is very low </li></ul><ul><li>Hydrophobic acrylic AcrySof® leads to the lowest incidence of PCO. 3 A study with a 3-year follow-up showed that hydrophobic acrylic IOLs yielded the lowest percentage of PCO (10%) followed by silicone (40%) and poly(methyl methacrylate) (PMMA) (56%) lenses. 2 </li></ul>
  5. 5. <ul><li>Sharp truncated optic edge combined with total cover of the optic by the anterior capsule is crucial to blocking the migration of lens epithelial cells. </li></ul><ul><li>There are 2 conflicting theories on the mechanism. Nishi and coauthors 22 postulate that cell contact inhibition is responsible for reduced PCO with square-edged IOLs, while Boyce and coauthors 23 suggest the phenomenon may be caused by a mechanical pressure barrier effect at the sharp optic edge. </li></ul>
  6. 6. <ul><li>It also seems that overall IOL size is important in preventing PCO, with a 6.0 mm optic leading to less PCO than a 5.5 mm optic 2 years after surgery. 24 The above factors undoubtedly influenced the low incidence and severity of PCO with both IOLs in our study. </li></ul>
  7. 7. Incidence of PCO <ul><li>11.8% - 1 year </li></ul><ul><li>20.75% – 2 years </li></ul><ul><li>28.55% - 3 years </li></ul>
  8. 8. What is the study about? <ul><li>Means and approaches to prevent or delay PCO </li></ul><ul><li>Not looking at : </li></ul><ul><li>How to quantify PCO most common used POCOMAN </li></ul><ul><li>http:// www.ph.kcl.ac.uk/POCOMAN .html </li></ul><ul><li>Ocular or systemic factors </li></ul>
  9. 9. Clinical approaches to PCO prevention <ul><li>Non IOL related </li></ul><ul><li>Surgical </li></ul><ul><li>Anterior CCC size </li></ul><ul><li>Posterior CCC </li></ul><ul><li>Capsule polishing </li></ul><ul><li>Cortical clean up </li></ul><ul><li>Mechanical </li></ul><ul><li>Capsular tension ring </li></ul><ul><li>Chemical </li></ul><ul><li>Heparin </li></ul><ul><li>IOL related </li></ul><ul><li>Surgical </li></ul><ul><li>Placement site of IOL </li></ul><ul><li>Mechanical </li></ul><ul><li>IOL optic edge </li></ul><ul><li>Chemical </li></ul><ul><li>Surface coating </li></ul>
  10. 10. The study <ul><li>Prospective randomised controlled </li></ul><ul><li>Primary end point: </li></ul><ul><li>To evaluate the relationship of the anterior capsule and AcrySof MA 30 IOL and its impact on the development of central PCO </li></ul><ul><li>Secondary end point: </li></ul><ul><li>Incidence of PCO in the 3 zones of the capsule </li></ul>
  11. 11. Inclusion criteria <ul><li>202 consecutive patients with senile cataracts over 50 yr old operated on over 6/12 in India </li></ul><ul><li>One surgeon </li></ul><ul><li>Same cataract technique </li></ul><ul><li>Ethics committee approved </li></ul><ul><li>Informed consent </li></ul><ul><li>Pupil dilatation more than 7mm </li></ul><ul><li>Hypertensive included </li></ul>
  12. 12. Exclusion criteria <ul><li>Co-morbidity or previous intraocular surgery </li></ul><ul><li>Black </li></ul><ul><li>On topical or systemic NSAIDS or steroids </li></ul>
  13. 13. Method <ul><li>Same surgical technique </li></ul><ul><li>Topical anesthetic </li></ul><ul><li>Temporal clear corneal incision </li></ul><ul><li>Acrysoft MA30 5.5mm optic and 12.5mm diameter in the bag </li></ul><ul><li>After IOL implanted and before viscoelastic removed </li></ul><ul><li>Randomization: envelope </li></ul>
  14. 14. Randomization groups <ul><li>1. Anterior capsule covering completely the edge of IOL </li></ul><ul><li>2.Anterior capsule totally off the IOL edge </li></ul><ul><li>3. Anterior capsule partially covered the edge of IOL </li></ul>
  15. 15. Assessment <ul><li>1/52 </li></ul><ul><li>1/12 </li></ul><ul><li>6/12 </li></ul><ul><li>12/12. </li></ul><ul><li>18 patients excluded as no f/u(6,4,6). </li></ul><ul><li>Single observer. </li></ul><ul><li>No eye required Yag laser at 3 years. </li></ul>
  16. 20. Does this research add to literature in any way? <ul><li>Will the result add information to a meta-analysis? </li></ul><ul><li>Is there sufficient doubt in the mind of the reader to make new evidence desirable even when not scientifically necessary? </li></ul>
  17. 21. . Incidence of Posterior Capsule Opacification in the Peripheral Zone of the Posterior Capsule                                                                                                                        .
  18. 22. Incidence of PCOn in the Midperipheral Zone of Posterior Capsule                                                                                                                                                                                                                                                                                                                                                                          
  19. 23. Incidence of PCO in the Central Zone of the Posterior Capsule                                                                                                                       
  20. 24. Conclusion <ul><li>When using Acrysoft mode MA30 the relationship of the AC and the IOL is not a factor that relates to the development of central PCO at 3 years. </li></ul><ul><li>Confirms suggestion of retrospective study that at 3 years overlap of the anterior capsule is more critical with SI40 than with AcrySof 3-piece. </li></ul><ul><li>Peripheral opacification was slow and similar between the groups. </li></ul><ul><li>Midperipheral opacification was present in 24.2% in group 1, 16% in group 2 and 20.65 9n group 3. </li></ul>
  21. 25. Power and limitations <ul><li>Power close to 80%. </li></ul><ul><li>Degree of PCO has not been assessed, only presence or absence. </li></ul>
  22. 26. Take home message <ul><li>A total cover of the optic when using AcrySof MA30 does not seem to be compulsory. </li></ul>

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