Eyelid Flashcards
Telecanthus
abnormally increased distance between the. medial canthi of the eyelids
Poliosis
whitening of the eyelashes
Madarosis
loss of eyelashes
Trichiasis
turning inward of eyelashes, often secondary to entropion
Phthiriasis palpebrarum
an infection of the eyelashes caused by Phthirus pubis
Layers of the eyelid
- Skin Layer
thin layer of skin that contains fine hairs, sweat glands, and sebaceous glands. The skin layer of the eyelid is unique because it is the thinnest in the body and contains no fat
- Subcutaneous areolar layer
thin layer of loose connective tissue that lies between the outer skin and the underlying orbicularis. The upper lid (of) contains the levator of aponeurosis as it travels to its insertion within the skin and upper tarsal plate
- Orbicularis layer
Contains the palpebral portion of the orbicularis oculi, one of the muscles of facial expression innervated by CN VII
a. Orbicularis oculi
2 portions: Orbital portion and Palpebral portion
i. Orbital portion
attaches to the orbital margins and extends outward. Used for forced closure of the eyelids
ii. Palpebral portion
used for spontaneous and reflex blinking. contains two specialized areas
2 specialized areas of palpebral portion of the orbicularis oculi
- Muscle of Riolan - referred to as the pars ciliaris
- Muscle of Horner - referred to as pars lacrimalis
- Muscle of Riolan (palpebral portion of the orbicularis oculi)
The most superficial portion of the orbicularis oculi (subtarsal portion) that keeps the lid margin tightly applied to the globe during eye movements; may contribute to rotating the eye-lashes toward the eye during eyelid closure
- Muscle of horner (^)
consists of fibers from the orbicularis (originating from the posterior lacrimal crest and fascia of the lacrimal sac) that encircle the canaliculi and help drain tears into the lacrimal sac
Ectropion
paralysis of the orbicularis will cause the lower eyelid to droop away from the globe, resulting in
Back to the layers of the eyelid categories
- Submuscular areolar layer
thin layer of loose ct that is between the orbicularis and orbital septum. Upper lid (of) contains the levator aponeurosis and palpebral portion of main lacrimal gland. Peripheral and marginal arcades are present in this layer within the upper and lower eyelids
- Orbital septum
dense irregular ct that serves as a barrier to the orbit in the upper and lower eyelids. Prevents fat from falling down onto the lid margins and keeps infections localized to anterior part of the eyelid, away from the orbit
(info within orbital septum) A. Periorbita
loosely covers the orbital bones and projects anteriorly to become the orbital septum and posteriorly to fuse with the dura of optic nerve
