The document discusses aphakia, which is the absence of the crystalline lens from the eye. This can be caused by congenital issues, lens absorption, trauma, or surgical removal of the lens. Symptoms include defective vision and visual distortions. For aphakic patients to see clearly, they require optical rehabilitation like spectacles, contact lenses, or intraocular lenses. The document then focuses on the types, history, and surgical techniques for implanting different kinds of intraocular lenses.

2.  Removal of the cataractous lens
renders
the patient Aphakic.
Aphakia- Aphakia literally means
absence of crystalline lens from
the eye.

3. causes
 Congenital absence of lens.
 Due to absorption of lens matter.
 Traumatic extrusion of lens.
 Posterior dislocation of lens.
 Surgical aphakia occuring after removal
of lens.

4. symptoms
 Defective vision.
 Erythropsia & cynopsia(i.e.seeing red &
blue images)

5. sign
 Anterior chamber is deep.
 Iridodonesis.
 Pupil is jet black.
 Retinoscopy reveals high
hypermetropia.

6. For the pt. to be able to see clearly
some form of optical rehabilitation
must be provided.
This may be in the form of
1.Spectacles
2.Contact lenses
3.Intraocular lens

7. Comfort & Optical Aniseikonia
convenience aberration
spectacle •Heavy •Visual •Magnification
•Cosmetically distortion, pin of 20-30% so
poor cushion effect produces
because of diplopia
central
magnification
Contact •Insertion & nil •Magnification
lens removal about
cumbersome 8%,tolarable
Iol Comfertable nil •Magnification
in every way 1-
2%,negligible

8. INTRAOCULAR LENS
 The central part overlying the optic axis
is called Optic.
 Peripheral arms used for placement &
stabilization are the Haptic.

9. History
 Intraocular lens implant history had its
beginning on Nov.29,1949 when Harold
Ridley, a British ophthalmologist
performed his 1st case.

10. Types of IOLs
 Anterior chamber IOL
 Iris-supported lenses
 Posterior chamber lenses

11. Anterior chamber IOL
 Lie in front of iris & supported in the
angle of anterior chamber.
 ACIOL inserted after ICCE or ECCE.
 It is not so popular due to comparatively
higher incidence of bullous keratopathy.
 Kelman multiflex type of ACIOL is used.

12. Iris supported lenses
 These lenses are fixed on the iris with
the help of sutures, loops or claws.
 These lenses also have a high
incidence of postoperative complication.
 E.g. Singh & Worst’s iris claw lens.

13. Posterior chamber lenses
 PCIOLs rest entierly behind the iris.
This may be supported by the ciliary
sulcus or the capsular bag, recent trend
is towards in the bag fixation.
 Depending on material of
manufacturing,types of PCIOLs are
available

14.  Rigid IOLs- made entirely from
PMMA.
 Foldable IOLs- use after
Phacoemulsification are made of
silicon, acrylic, hydrogel & collamer.
 Rollable IOLs- It is after phakonit
technique.made of hydrogel.

15. Calculatio of IOL power-
 Most common method is SRK formula
by regression formula.
 P=A-2.5L-0.9K
 P=power of IOL
 A=constant
 L=axial length of eyeball.

16.  For long eyeball some adjustment is
made in the formula by taking new
constant A1.

17. A1(new const.) Axial lenth of eye
A1 3 <20mm
A1 2 20 to <21mm
A1 1 21 to <22mm
A 22 to 24.5 mm
A-0.5 >24.5mm

18. Surgical technique of ACIOL
implantation
 Can be carried out after ICCE & ECCE.
 After lens extraction, the pupil is
constricted by injecting miotics into A.C.
 A.C. is filled with 2% methylcellulose or
1% sodium hyaluronate.
 IOL,held by a Forceps gently slid into
A.C.

19.  Inferior haptic is pushed in the inferior
angle at 6o’ clock position & upper
haptic is pushed to engage in the upper
angle.

20. Technique of posterior
chamber IOL implantation
 Implantation of rigid IOL-
 It implanted after ECCE.
 Capsular bag & A.C. is filled with 2%
methylcellulose or 1%sodium
hyaluronate.
 IOL,hold by a Forceps.

21.  Inferior haptic is pushed in the inferior
angle at 6o’ clock position
 The superior haptic is grasped by tip, &
is gently pushed down & then released
to slide in the upper part of the capsular
bag behind the iris.
 The IOL is then dilated into the
horizontal position.

22.  Implantation of foldable IOLs is made
either with the help of holder-folder
forceps or the foldable IOLs injector.

23. References
 Parsons’ diseases of the eye.