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PROBLEMS OF APHAKIA & IOL

PROBLEMS OF APHAKIA & IOL. Maj M. Ahsan Mukhtar FCPS, FRCS (Glasg) CLASSIFIED EYE SPECIALIST REGISTRAR VITREO-RETINAL SURGERY. OBJECTIVES. Enlist common problems of aphkaia Briefly describe the mechanism / physics of these problems Know basics of intraocular lenses. PROBLEMS OF APHAKIA.

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PROBLEMS OF APHAKIA & IOL

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  1. PROBLEMS OF APHAKIA & IOL Maj M. Ahsan Mukhtar FCPS, FRCS (Glasg) CLASSIFIED EYE SPECIALIST REGISTRAR VITREO-RETINAL SURGERY

  2. OBJECTIVES • Enlist common problems of aphkaia • Briefly describe the mechanism / physics of these problems • Know basics of intraocular lenses

  3. PROBLEMS OF APHAKIA • Relative spectacle magnification (RSM) • Anisometropia in unilateral aphakia • Aberrations • Heavy lenses (glasses) • Visual field limitation • Loss of ultra-violet protection • Other problems • Cystoid Macular edema • Retinal Detachment • Increase In Proliferative Diabetic Retinopathy • Amblyopia in children with unilateral aphakia

  4. PROBLEMS OF APHAKIA • Relative spectacle magnification (RSM) • Anisometropia in unilateral aphakia • Aberrations • Heavy lenses (glasses) • Visual field limitation • Loss of ultra-violet protection • Other problems • Cystoid Macular edema • Retinal Detachment • Increase In Proliferative Diabetic Retinopathy • Amblyopia in children with unilateral aphakia

  5. RELATIVE SPECTACLE MAGNIFICATION • The ratio between the corrected and uncorrected image size • Image is 33% larger in corrected aphakia • Patient may misjudge distances • Actual VA of an Aphakic reading 6/9 is approx 6/12

  6. RELATIVE MAGNIFICATION AND IMAGE SIZE SOLUTION • Intra-ocular lens • Contact lens • Isiekonic lens • Corneal procedures

  7. PROBLEMS OF APHAKIA • Relative spectacle magnification (RSM) • Anisometropia in unilateral aphakia • Aberrations • Heavy lenses (glasses) • Visual field limitation • Loss of ultra-violet protection • Other problems • Cystoid Macular edema • Retinal Detachment • Increase In Proliferative Diabetic Retinopathy • Amblyopia in children with unilateral aphakia

  8. ABERRATIONS IMAGE DISTORTION troublesome to the newly aphakic patients Straight lines appears curved except when viewed through a very small axial zone of lens

  9. ABERRATIONS RING SCOTOMA The prismatic power of the more peripheral parts of a spherical lens

  10. ABERRATIONS JACK-IN-THE-BOX The direction of the scotoma changes as the patient moves his eyes, and objects may appear out of the scotoma or disappear into it. SOLUTION Tell the patient to move his head instead of moving eyes while wearing aphakic glasses

  11. PROBLEMS OF APHAKIA • Relative spectacle magnification (RSM) • Anisometropia in unilateral aphakia • Aberrations • Heavy lenses (glasses) • Visual field limitation • Loss of ultra-violet protection • Other problems • Cystoid Macular edema • Retinal Detachment • Increase In Proliferative Diabetic Retinopathy • Amblyopia in children with unilateral aphakia

  12. HEAVY GLASS LENSES • Use plastic lenses

  13. PROBLEMS OF APHAKIA • Relative spectacle magnification (RSM) • Anisometropia in unilateral aphakia • Aberrations • Heavy lenses (glasses) • Visual field limitation • Loss of ultra-violet protection • Other problems • Cystoid Macular edema • Retinal Detachment • Increase In Proliferative Diabetic Retinopathy • Amblyopia in children with unilateral aphakia

  14. VISUAL FIELD LIMITATION • SOLUTION Ask Patient to move head instead of moving eyes while wearing aphakic glasses

  15. PROBLEMS OF APHAKIA • Relative spectacle magnification (RSM) • Anisometropia in unilateral aphakia • Aberrations • Heavy lenses (glasses) • Visual field limitation • Loss of ultra-violet protection • Other problems • Cystoid Macular edema • Retinal Detachment • Increase In Proliferative Diabetic Retinopathy • Amblyopia in children with unilateral aphakia

  16. LOSS OF ULTRA-VIOLET PROTECTION • SOLUTION • Intra-ocular lens with UV protection • Glasses with UV protection

  17. PROBLEMS OF APHAKIA • Relative spectacle magnification (RSM) • Anisometropia in unilateral aphakia • Aberrations • Heavy lenses (glasses) • Visual field limitation • Loss of ultra-violet protection • Other problems • Cystoid Macular edema • Retinal Detachment • Increase In Proliferative Diabetic Retinopathy • Amblyopia in children with unilateral aphakia

  18. OTHER PROBLEMS DUE TO APHAKIA • Cystoid Macular edema • Retinal Detachment • Increase In Proliferative Diabetic Retinopathy • Amblyopia in children with unilateral aphakia • Occlusion therapy • IOL • Contact lenses

  19. INTRA OCULAR LENSES

  20. INTRA OCULAR LENSES The optic (the central refracting element) The heptics

  21. IOL MATERIAL • Optic • Polymethylmethacrylate (PMMA) • Silicon • Acrylic (hydrophillic and hydrophobic) • Hydrogel • Heptics • Polypropylene (3 piece) • Same material as optics (1 piece)

  22. IOL DESIGN

  23. TYPES OF IOL AC IOL Iris claw Lens PC IOL

  24. IOL TYPES Monofocal IOL Multifocal IOL Toric Accomodative

  25. PLACEMENT OF IOL IN EYE • The posterior chamber (PC IOL) • capsular bag • Sulcus • The anterior chamber (AC IOL) • Iris / pupil supported • Angle supported

  26. AC-IOL

  27. PC IOL • PC IOL • PC IOL in Capsular bag

  28. RIGID VS FOLDABLE IOL’S • Rigid • PMMA • One piece to facilitate maximal stability and fixation • Foldable • Silicone IOLs: have lower rates of posterior capsular opacification than PMMA IOLs • Acrylic IOLs • Hydrogel IOLs: have higher water content • Collamer IOLs : are a mixture of collagen and hydrogel (newly developed)

  29. ADVANTAGES OF IOLs All problems of aphakia ------ gone Broader field of view Lesser problem of image magnification Binocularity is maintained

  30. DISADVANTAGES OF IOLS Problems of accommodation Chances of dislocation into the vitreous UGH syndrome with AC-IOL Endothelial decompensation

  31. THANK YOU

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