It can be seen as opacity in lens material with echoes inside the lens or increased anteroposterior diameter of the lens with a high echogenicity of the posterior capsule.
Also can be seen both images.
The lens can be moved from its normal position,
normally to posterior segment.
Lens dislocation is caused by damage to the zonular fibers (suspensory ligament) that keep the lens in place,
and can be seen in ocular trauma and Marfan syndrome.
It occurs in 50% of patients over age 50,
more frequently and earlier in subjects with myopia.
B-scan reveals point-like and membrane-like echoes,
with a rapid initial movement and a fluid after-movements.
This is not specific for degenerative condition,
we can see similar images in hemovitreous or hyalitis.
It has been associated with diabetes mellitus,
hypertension and hypercholesterolemia.
We can see calcium particles like little focal or diffuse opacities with high echogenicity,
without any posterior acoustic shadowing and fluid characteristic movements.
The most frequent causes are the rupture of sclerotic vessels,
diabetic retinopathy or tumors.
There are several stages of hemorrhage showing different morphological characteristics.
In early stages B-scan reveals very low echogenicity thin echoes,
with considerable movements.
In its evolution,
opacities acquire medium echogenicity,
with the same fluid movements.
Then forming high echogenicity fibrin clots,
and may be formed thick membranes which moving fluidly with eye movements at beginning,
and after become rigid and fixed to posterior wall,
being able to cause a retinal detachment.
- PERSISTENT HYPERPLASTIC PRIMARY VITREOUS
It is a rare congenital developmental anomaly of the eye,
a failure of normal primary vitreous regression (formed by the hyaloid artery) that is not replaced by the secondary or adult vitreous.
It is important to use colour Doppler for the differential diagnosis with retinoblastoma and other leucocoria.
Ultrasound reveals a little eye ball (microphthalmia),
an hiperechogenic mass behind the lens,
and an echogenic band extending from posterior surface of the lens to the optic nerve head.
On colour Doppler,
this band shows an arterial blood flow,
due to the persistence of the hialoid artery.
- POSTERIOR VITREOUS DETACHMENT
The detachment may be complete or incomplete.
Incomplete detachment may present fixation areas to the posterior wall,
being able to observe retinal traction.
In complete detachment there is no relationship with the posterior wall.
B-scan shows a thin membrane with very low echogenicity and sometimes it is necessary increasing the gain to see it. This membrane has a concave shape parallel to the posterior wall.
the vitreous shows increased after movements.
With colour Doppler there is absence of flow,
which differentiates it from retinal detachment.
Accumulation of fluid between the neuroepithelium and retinal pigment epithelium in the "subretinal" space.
It can be seen like a high echogenicity thick membrane,
from the optic disc to the ora serrata when the detachment is complete.
It takes morphology in "V" in its early stages; "Y" or "T" when it evolves without treatment.
May be mobile in the acute phase,
becoming more rigid in cases of chronic detachments.
Vascularization is detected with Doppler (arteriovenous flow).
High echogenicity thick membrane with a convex configuration.
It forms an obtuse angle with the posterior wall not detached.
Movements are scarce or absent.
Colour Doppler reveals arterial flow.
They are tumors that affect the uveal tract (iris,
cilliary body and choroid).
Small tumors show middle and homogeneous echogenicity,
a biconvex lens appearance and they have usually a regular outline.
Larger tumors are lower-echogenicity lesions and can present cystic areas representing areas of necrosis or hemorrhage.
They are usually mushroom-shaped and they have an irregular outline.
These tumors present smooth attenuation.
Colour doppler examination of these tumors will show evidence of perfusion in most instances.
It is frequently associated with retinal detachment,
and vitreous hemorrhage occasionally.
They are difficult to differentiate from melanoma.
They are usually more irregular,
more echogenic and vascularized and may be multiple.
The most frequent metastasis are usually from breast and lung cancer.