hi let's talk about the palpebral fissures and palpebrae or the eyelids so the palpebral
fissure is the space between the palpebrae or the eyelid so here I'll outline it here
and therefore it is the space through which the eye can encounter the external world there are
two sides to the palpebral fissure there is a lateral angle or campus and a medial angle or
canthus the palpebrae themselves are somewhat complex layer wise from superficial to deep
we have the skin of the eyelids and then the the sub-q the subcutaneous tissue then we have
some of the the palpebral fibers of orbicularis oculi and then deep to that those orbicularis
oculi fibers we have the tarsofascial layer of the palpebrae and then and then deep to
the tarsofascial layer of the palpebrae we then have the palpebral conjunctiva and that palpebral
conjunctiva is going to be in close contact with the bulbar conjunctival which is upon the eye so
let's really focus on this tarsofascial layer here this is a very underappreciated part of
the of the orbit so the the first element here that I'd like to draw your attention to is the
orbital septum the the orbital septum is a very weak membranous layer that's contiguous with the
orbital periosteum so all around the rim of the orbit the the periosteum those bones is
contiguous and it sends this orbital septum and the septum is weaving its way around elements
like the superior and inferior tarsal plates which are giving structure and support to the palpebrae
they're weaving behind the medial palpebral ligament in the lateral palpebral ligament
which are anchoring the palpebrae at the angles or the camp thigh and this is important because
it's going to serve as a frame of reference to differentiate clinically free septal orbital
cellulitis from postseptal orbital cellulitis preseptal orbital cellulitis can come from a
superficial injury or you know an infection or a bug bite might present like a swollen eye many
of you have probably experienced that before or at least I've seen it before you know preseptal
orbital cellulitis is is outpatient treatment you know postseptal orbital cellulitis is usually the
result of movement of infection from another deep space so I mean it could be cellulitis
from typically it would be the ethmoidal air cells or the sphenoid sinus mostly the the
ethmoidal air cells cavernous sinus etc those those post septal cellulitis they they can be
very serious and require you know inpatient therapy and very rigorous IV antibiotics so
when people are discussing the two types of orbital cellulitis pre septal and post septal
they're actually referencing this orbital septum here and so this the starship tar so facial layer
of the eye is is supporting the the palpebrae and allowing them to to work to protect and to
keep the the surface of the eye lubricated also embedded within the the tar so facial layer are
going to be tarsal glands and these tarsal glands are going to pores along the outer margins of the
palpebrae and some of these you can you can see quite well if you look at the at the conjunctiva
the palpebral conjunctiva adjacent to these glands you can see how it's a little lighter
in spaces so that glandular material isn't as as dark as the vasculature that's going to surround
it or interleave between those two elements so we've discussed the the orbital fissure and the
medial lateral angles or can't thigh as well as the layers of tissue of the palpebrae skin
sub-q orbicularis oculi palpebral fibers that Tarso facial layer then finally the palpebral
conjunctiva and some of the elements of that tarzo facial layer thank you very much for your time