Transcript Problems-of-Aphakia

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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Relative spectacle magnification (RSM)
Anisometropia in unilateral aphakia
Aberrations
Heavy lenses (glasses)
Visual field limitation
Loss of ultra-violet protection
Other problems
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


Cystoid Macular edema
Retinal Detachment
Increase In Proliferative Diabetic Retinopathy
Amblyopia in children with unilateral aphakia
PROBLEMS OF APHAKIA
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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
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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
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Intra-ocular lens
Contact lens
Isiekonic lens
Corneal procedures
PROBLEMS OF APHAKIA
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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
ABERRATIONS
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 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
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Use plastic lenses
PROBLEMS OF APHAKIA
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





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 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
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SOLUTION

Intra-ocular lens with UV protection
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Glasses with UV protection
PROBLEMS OF APHAKIA
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





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
OTHER PROBLEMS DUE TO
APHAKIA
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Cystoid Macular edema
Retinal Detachment
Increase In Proliferative Diabetic Retinopathy
Amblyopia in children with unilateral aphakia
 Occlusion therapy
 IOL
 Contact lenses
INTRA OCULAR LENSES
INTRA OCULAR LENSES
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The optic (the central
refracting element)
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The heptics
IOL MATERIAL
Optic
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Polymethylmethacrylate (PMMA)
Silicon
Acrylic (hydrophillic and hydrophobic)
Hydrogel
Heptics
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Polypropylene (3 piece)
Same material as optics (1 piece)
IOL DESIGN
TYPES OF IOL
AC IOL
Iris claw Lens
PC IOL
IOL TYPES
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Monofocal IOL
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Multifocal IOL
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Toric
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Accomodative
PLACEMENT OF IOL IN EYE
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The posterior chamber (PC IOL)
 capsular bag
 Sulcus
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The anterior chamber (AC IOL)
 Iris / pupil supported
 Angle supported
AC-IOL
PC IOL
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PC IOL
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PC IOL in Capsular
bag
RIGID VS FOLDABLE IOL’S
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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
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Broader field of view
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Lesser problem of image magnification
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Binocularity is maintained
DISADVANTAGES OF IOLS
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Problems of accommodation
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Chances of dislocation into the vitreous
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UGH syndrome with AC-IOL
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Endothelial decompensation
THANK YOU