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