Interactive Transcript
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Thus far, we have reviewed the traumatic injuries and
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infectious inflammatory injuries of the globe.
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This next entity,
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Persistent Hyperplastic Primary Vitreous,
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sort of crosses the boundaries between a congenital
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abnormality as well as a vascular abnormality
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when we're using our vitamin C and D mnemonic.
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These are two different patients who have PHPV.
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Both of the patients show microphthalmos on the left side.
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In both of the cases,
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one sees a vertically oriented line which leads from the
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region of the retina anteriorly to the lens of the eye.
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This is the persistence of the embryonic
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hyaloid vascular system,
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the hyaloid artery in what is known as Cloquet's canal.
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PHPV is discovered in infants who demonstrate
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leukocoria, as well as microphthalmos.
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However,
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these patients may also present with retinal hemorrhages.
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Because of the abnormal development of the
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choroid and retina in these patients,
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the retinal hemorrhages may not follow the typical
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location that we say with regard to 10 o'clock
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and 2 o'clock along the globe.
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In this case,
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the upper image shows an area of blood products
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in the affected left globe which extends far anteriorly,
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greater than expected for our typical retinoblastoma,
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which should end at the ora serrata
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at 10 o'clock and 2 o'clock
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As you can see,
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the lens of the eye and the ciliary apparatus is generally
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abnormally developed in patients who have PHPV.
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And therefore, retinal detachments may proceed further
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anteriorly than typical in a normal eye.
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To distinguish this lesion from retinoblastoma,
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remember we say that PHPV does not calcify and is usually
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associated with a small globe as opposed to the most
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common cause of leukocoria, retinoblastoma,
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which is associated with a normal-sized
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globe or slightly larger globe.
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The abnormal lens is another factor that
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distinguishes PHPV from retinoblastoma,
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which has a normal lens of the eye.
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The next congenital anomaly that we wish to speak
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about is the coloboma.
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A coloboma is a congenital
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anomaly where there is a defect in the
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retina and the ocular membranes.
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This is typically projecting into the insertion site of
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the optic nerve.
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Although, you can have colobomas,
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medially and laterally located.
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Colobomas are diseases that we see in infancy
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and they are to be distinguished from the other entity
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that may cause an enlarged,
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elongated globe, the staphyloma.
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Staphyloma is seen on these images.
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Once again, with staphyloma,
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we see thinning of the uveoscleral membrane
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as opposed to the normal thickness
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of those ocular membranes.
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And usually, staphylomas project towards
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the temporal side of the globe.
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The most common cause of staphyloma is axial myopia.
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However, one can see it after trauma
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or endophthalmitis, anything that causes weakening
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of the uveoscleral membranes.
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You may also see this with rheumatoid arthritis
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and other collagen vascular diseases.
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