Aphakia refers to the absence of the crystalline lens, resulting from various causes such as congenital defects, surgical removal, or trauma. The condition leads to significant refractive issues, including high hypermetropia and loss of accommodation, manifesting in symptoms like defective vision and unique visual phenomena. Treatment options include spectacles, contact lenses, intraocular lens implantation, and emerging refractive surgery, each having specific advantages and disadvantages.

1. APHAKIA
CAUSES, OPTICS, CLINICAL FEATURES
AND TREATMENT
Dr Khushmina Khan

2. Aphakia
 Aphakia literally means absence of crystalline lens
 From an ophthalmological point of view, aphakia is the
absence of the lens in the pupillary area.

3. CAUSES OF APHAKIA
 Congenital aphakia
 Surgical aphakia – removal of lens as in cataract
extraction
 Aphakia due to absorption of lens – sometimes seen in
children after trauma
 Traumatic extrusion of lens
 Posterior dislocation of lens into the vitreous causes
optical aphakia

4. OPTICS IN APHAKIA
 The lens is important in refraction and hence its removal
results in considerable decreased in the refractory power
of the eye
 The eye becomes highly hypermetropic
 The power of eye decreases from +60D to +44D
 The power of accommodation lost
 The posterior focal point lies behind the eyeball

5. Clinical features
 Symptoms
 Defective vision – due to high hypermetropia and loss
of accommodation
 Erythropsia and cyanopsia – due to entry of infrared and ultraviolet
rays in the absence of the crystalline lens

6.  Signs (anterior to posterior)
 Limbal scar in case of surgical aphakia
 Deep anterior chamber
 Iridodonesis – tremulousness of the iris due to loss of support of
lens
 Jet Black pupil
 Loss of 3rd and 4th purkinje images
 Fundus examination reveals a small hypermetropic fundus
 Retinoscopy shows high hypermetropia

7. Treatment:
 Spectacles
 Spectacles should be prescribed with about +10D lens for correction
of aphakia
 It should also include correction for surgical astigmatism and +3-4D
for near vision
 Nowadays spectacles are not preferred for use in aphakia due to its
many disadvantages

8. Advantages and Disadvantages of using spectacles in
APHAKIA
 Advantages
 Cheap
 Easy to use
 No complications
 Disadvantages
 The images are magnified – about 30% – hence not useful in unilateral
aphakia as it causes diplopia
 The field of vision in decreased considerably
 Spherical and chromatic aberration of high power lenses
 Roving ring scotoma (Jack in the box phenomenon)
 Prismatic effect of the thick lenses
 High power are cosmetically not acceptable

9. Contact lenses
 Advantages over spectacles:
 Produces less magnification
 Better field of vision
 Less chromatic and spherical aberration
 No prismatic effect
 Cosmetically more acceptable
 Disadvantages
 Costly
 More care in required usage of contact lenses – may not be suitable for
use in young children and elderly
 Complications related to use of contact lenses

10. Intraocular lens implantation
 This is the preferred method nowadays
 The lens can be implanted in the capsular bag or in the anterior
chamber
 It eliminates most of the disadvantages associated with the use of
spectacles or contact lenses
 Disadvantage include the complications associated with surgery

11. Refractive surgery
 – This is a newly emerging treatment for aphakia
 Keratophakia
 a lenticule prepared from the donor cornea is placed within the lamellae
of the patient’s cornea
 Epikeratophakia
 a lenticule prepared form the donor cornea is stitched to the patients
cornea after removing the epithelium
 Hyperopic Lasik

12. Thank You