corneal trasplantation.ophtaaa

1. Phthisis bulbi

2. • Phthisis bulbi is defined as atrophy, shrinkage, and disorganization of the
eye and intraocularcontents.
• Many blind eyes pass through several stages of atrophy and
disorganization before progressing to the end stage of phthisis bulbi:
Atrophia bulbi without shrinkage.
• In this initial stage, the size and shape of the eye are maintained despite
the atrophy of intraocular tissues.
• The following structures are most sensitive to loss of nutrition:
– the lens, which becomes cataractous;
– the retina, which atrophies and becomes separated from the RPE by serous
fluid accumulation; and
– the aqueous outflow tract, where anterior and posterior synechiae develop.

3. Cont…
Atrophia bulbi with shrinkage.
• In this stage, the eye becomes soft because of ciliary bodydysfunction and the
progressive diminution of IOP.
• The globe becomes smaller and assumes a squared-off configuration as a result
of the influence of the 4 rectus muscles.
• The anterior chamber collapses.
• Associated corneal endothelial cell damage initially resultsin corneal edema,
followed by opacification from degenerative pannus, stromal scarring,and
vascularization.
• Most of the remaining internal structures of the eye will be atrophic but
recognizable histologically.

4. Cont…
Phthisis bulbi
• In this end stage, the size of the globe shrinks from a normal average diameter of
23–25 mm to an average diameter of 16–19 mm.
• Most of the ocular contents become disorganized.
• In areas of preserved uvea, the RPE proliferates, and drusen may develop.
• In addition, extensive dystrophic calcification of Bowman layer, lens,
retina, and drusen usually occurs.
• Osseous metaplasia of the RPE with bone formation may be a prominent feature.
• Finally, the sclera becomes markedly thickened, particularly posteriorly.

5. Cont…
• Phthisis bulbi represents an ocular end stage disease characterized by
– atrophy, shrinkage, and disorganization of the eyeball and intraocular contents.
• It is derived from the Greek word phthiein or phthinein, meaning shrinkage or
consuming.
• Atrophy and phthisis bulbi refer to consecutive stages in the degeneration process:

6. Cont…
• Stage 1
– is ocular atrophy without shrinkage, in which there is atrophy of intraocular
structures such as the retina and uvea in a normal size or even enlarged eye
(bupthalmos) such as diffuse atrophy in longstanding glaucoma;
• Stage 2
– is ocular atrophy with shrinkage (aka atrophia bulbi), which refers to atrophy of
intraocular structures, plus atrophy of the globe so that it is smaller than normal;
• Stage 3
– is ocular atrophy with shrinkage and disorganization, known as phthisis bulbi

7. Optociliary shunt vessels can be classified as congenital or acquired.
• Congenital cases are rare. They represent a vascular malformation that connects the
retinal and choroidal venous circulations.
• Acquired causes of optociliary shunt vessels
• Common
– Central and hemicentral retinal vein occlusion
– Optic nerve sheath meningioma
– Chronic glaucoma
• Less common
– Chronic papilledema
– Optic nerve head drusen
– Optic nerve glioma
– Arachnoid cyst of the optic nerve
– Phakomatoses
– Diabetic retinopathy

8. Cont…
• Optociliary shunt vessels are diagnosed on ophthalmic fundus exam, appearing
as tortuous vascular loops that start and end on the disc.
• Flow within these shunts can be documented in indocyanine green angiograms,
as well as during the venous phase of fluorescein angiography.
• They must be differentiated from neovascularization of the disc.
• Optociliary shunt vessels exhibit a larger caliber and do not cause leakage on FA