pictures in different cases of A-Scan

1. Presented by
Richa Gupta
B.Optom.,FOptom.
M.Optom(1 year)

2. MATURE CATARACT
 Strong sound attenuation production by a very dense
cataract can significantly impair the ability to display
spikes from the various interfaces along the visual
axis.
 Maximum gain setting may be required to obtain
spikes of sufficient height from the post. lens
capsule and retina.

3. Biometry scan in mature cataract

4. • Causes an irregular shape of
the ocular wall
• Inability to display a distinct ,
high retinal spike
• Deepest portion of the
staphyloma may be located
eccentric to macula, thus the
measurement may be longer
than true AL along the visual
axis.
2. Posterior
Staphyloma

5. RD
Edema
Tumor
3. Macular Lesions
An elevated macular lesion
may prevent the display of
a distinct retinal spike and
often causes a shortened
AL measurement.

6. RETINAL DETACHMENT
 RD is a disorder of the eye in which retina separates from the
layer underneath.
 Retinal detachment results in high amplitude spikes

7. Spikes seen in RD patients

8.  Asteroid Hyalosis
 Vitreous Hemorrhage
 Gas Bubble
4. Vitreous Lesions

9. ASTEROID HYALOSIS• Asteroid hyalosis is a
degenerative condition of the
eye involving small white
opacities in vitreous humor.
• It is a common clinical entity
in which calcium-lipid
complexes are suspended
throughout the collagen fibrils
of the vitreous.

10. Spikes seen in patients with asteroid hyalosis

11. INTRAOCULAR FOREIGN BODY
• Biometry is done by both
the techniques immersion
and contact and can find the
changes in spikes due to
foreign body.

12. BIOMETRY DONE BY IMMERSION TECHNIQUE

13. BIOMETRY DONE BY CONTACT TECHNIQUE

14. EXUDATIVE RD
 It occurs when blood or fluid from the middle
layer of tissue that forms the eyeball (choroid)
flows into the space under the retina and
separates the retina from the layer beneath it.
 The detachment does not involve tears in the
retina or traction from the vitreous.

15. EXUDATIVE RD

16. A-scan of right eye

17. A-scan of left eye

18. MICROPHTHALMIA
 Microphthalmia is a developmental disorder of eye in
which one or both eyes are abnormally small and have
anatomic malformation

19. Spikes seen in right eyes

20. Spikes of left eye

21. POST BUCKEL AXIAL LENGTH
 Rhegmatogenous RD usually requires prompt surgical
therapy.
 RD can be manage by pneumatic retinopexy , scleral
buckling (SB) or vitreoretinal surgery.
 These external techniques may not only lead to
changes in axial length but may also cause a reduction
in anterior chamber depth (ACD).

22. POST BUCKEL AXIAL LENGTH

23. Spikes of OD

24. A-SCAN IN CASE OF PSEUDOPHAKIA

25. a scan in case of air bubble