Download - PROBLEMS OF APHAKIA & IOL
PROBLEMS OF APHAKIA & IOL
Maj
M. Ahsan Mukhtar
FCPS, FRCS (Glasg)
CLASSIFIED EYE SPECIALIST
REGISTRAR VITREO-RETINAL SURGERY
OBJECTIVESOBJECTIVES
Enlist common problems of aphkaia
Briefly describe the mechanism / physics of these problems
Know basics of intraocular lenses
PROBLEMS OF APHAKIAPROBLEMS 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
PROBLEMS OF APHAKIAPROBLEMS 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
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
RELATIVE MAGNIFICATION AND IMAGE SIZE
SOLUTION
Intra-ocular lens Contact lens Isiekonic lens Corneal procedures
PROBLEMS OF APHAKIAPROBLEMS 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
ABERRATIONS
IMAGE DISTORTION
troublesome to the newly aphakic patients
Straight lines appears curved except when viewed through a very small axial zone of lens
ABERRATIONSABERRATIONS
RING SCOTOMA
The prismatic power of the more peripheral parts of a spherical lens
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
PROBLEMS OF APHAKIAPROBLEMS 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
HEAVY GLASS LENSES
Use plastic lenses
PROBLEMS OF APHAKIAPROBLEMS 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
VISUAL FIELD LIMITATION
SOLUTION
Ask Patient to move head instead of moving eyes while wearing aphakic glasses
PROBLEMS OF APHAKIAPROBLEMS 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
LOSS OF ULTRA-VIOLET PROTECTION
SOLUTION Intra-ocular lens with UV protection Glasses with UV protection
PROBLEMS OF APHAKIAPROBLEMS 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
Cystoid Macular edema Retinal Detachment Increase In Proliferative Diabetic Retinopathy Amblyopia in children with unilateral aphakia
Occlusion therapy IOLContact lenses
OTHER PROBLEMS DUE TO APHAKIA
INTRA OCULAR LENSES
INTRA OCULAR LENSES
The optic (the central refracting element)
The heptics
IOL MATERIAL
Optic Polymethylmethacrylate (PMMA) Silicon Acrylic (hydrophillic and hydrophobic) Hydrogel
Heptics Polypropylene (3 piece) Same material as optics (1 piece)
IOL DESIGN
TYPES OF IOL
AC IOL Iris claw Lens PC IOL
Monofocal IOL
Multifocal IOL
Toric
Accomodative
IOL TYPES
PLACEMENT OF IOL IN EYE
The posterior chamber (PC IOL) capsular bag Sulcus
The anterior chamber (AC IOL) Iris / pupil supported Angle supported
AC-IOL
PC IOL
PC IOL PC IOL in Capsular bag
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)
ADVANTAGES OF IOLs
All problems of aphakia ------ gone
Broader field of view
Lesser problem of image magnification
Binocularity is maintained
DISADVANTAGES OF IOLS
Problems of accommodation
Chances of dislocation into the vitreous
UGH syndrome with AC-IOL
Endothelial decompensation
THANK YOU