L13 - Ocular Lymph Supply Flashcards
(22 cards)
What is the function of the lymphatic system?
- Remove interstitial fluid and macromolecules (including proteins) to lymph nodes before entering blood circulation. 2. Carry immune cells to lymph nodes and control immunity in health and disease.
What are some lymphatic-specific molecules found in the eye?
LYVE-1, podoplanin, VEGFR-3, Prox-1, and lymphangiogenic factors like VEGF-C.
What tissues are lymphatic-rich in the eye?
Eyelids, lacrimal glands, conjunctiva, limbus, optic nerve sheath, extraocular muscles, connective tissues around muscle cones, and avian choroid.
What tissues are lymphatic-free in the eye?
Cornea, lens, iris, ciliary body, retina, choroid, and sclera.
What tissues are lymphatic-inducible in the eye?
Cornea, iris, and ciliary body.
Where are LYVE-1+ cells found in the eye?
Cornea, conjunctiva, limbus, iris, ciliary body, choroid, retina, sclera, extraocular muscles, and optic nerve sheath.
Why is the cornea typically devoid of vasculature?
It must maintain transparency as it is the forefront medium for light to reach the retina.
Under what conditions can lymphangiogenesis occur in the cornea?
Inflammatory, infectious, traumatic, chemical, or toxic insults.
Why is the lymphatic pathway critical in corneal transplantation?
It plays a key role in the induction of transplantation immunity.
What is the function of the conjunctival lymphatic system?
Supports essential metabolic function and provides immune effectors to the anterior eye compartment.
What are the three major structures of the uvea?
Iris, ciliary body, and choroid.
Are lymphatics normally found in the uvea?
No, but lymphatics have been identified in the avian choroid and may be induced pathologically in humans.
What pathological conditions can induce lymphatics in the uveal tract?
Progressive myopia, melanomas, and extraocular extension.
Does the retina have lymphatic vessels?
No, but LYVE-1+ cells are present. Functional role is not yet known.
What happens in cervical lymphostasis?
It can result in lymphostatic retinopathy.
How is the eyelid lymphatically drained?
Lateral 2/3 of eyelids → pre-auricular nodes; medial part → submandibular nodes.
Name two lymphatic-related disorders involving cancer or fluid retention.
Lymphatic invasion in tumors and chemosis (defects or blockades).
What ocular disorder is associated with lymphangiogenesis in the cornea?
Corneal inflammation.
What lymphatic condition is associated with chalazion?
Flattened lymphatics.
What lymphatic change is seen in dermatochalasis?
Lymphatic dilation.
What is the lymphatic characteristic of blepharochalasis?
Lymphatic proliferation and dilation.
What lymphatic issues are associated with conjunctival oedema and dry eye?
Structural defects and lymphangiogenesis, respectively.
