The Red Eye - PS Flashcards
What tissues make up the eyelids?
Skin, meibominan glands and conjunctiva
Where can you see redness in the eye?
Eyelids, conjunctiva, episclera, sclera, third eyelid, cornea, anterior chamber, anterior uvea, posterior uvea, retina, retrobulbar area
How could you get red eyelids?
Hyperaemia, swelling, ulcers, crusts, loss of hair
Dermatitis of various causes
Meibomian glands have a problem such as infection, neoplasia, granuloma
What are the eyelids intimately associated with?
Cornea and tear film
What knock on effects could be seen with red eyelids?
Loss of protective effect
Loss of oily part of tear film
Contact problem with eyelid hairs/masses and the cornea
What secondary pathologies could be seen as a result of eyelid pathology?
Corneal ulceration
Corneal vascularisation
Excessive tear production
What is the conjunctiva?
Mucus membrane lining of the sclera, 3rd eyelid and underside of eyelid that ends at the limbus (where the white meets the cornea)
What makes up the conjunctiva?
Epithelial cells
Mucus cells (goblet cells)
Lymphoid tissue
Blood vessels
What are the characteristics of conjunctival blood vessels?
Dichotomous branching
Very sensitive to surface irritation
How can conjunctival blood vessels cause redness?
Dilation of vessels and separation of endothelial cells leads to hyperaemia and oedema
What is the episclera?
Connective tissue under conjunctiva up to the limbs
Different looking blood vessels
What are the characteristics of episcleral blood vessels?
No dichotomous branching
Larger, meadner
What does the presence of episcleral blood vessels indicate?
Intra-ocular disease such as uveitis and glaucoma
Severe/chronic surface irritation in some cases
What is the sclera?
True white of the eye
Fibrous tunic continuous with the cornea via the limbus
Collagen fibres and fibroblasts
Emisaria are the holes in the sclera for blood vessels and nerves
What is the structure of the third eyelid?
Lots of lymphoid follicles in the bulbar side and palpebral side
T shaped cartilage core holds the third eyelid up against the eye
Contains the lacrimal gland
How can the third eyelid become red?
Hyperaemic
Cartilage curling outwards
Prolapse of lacrimal gland
What name is given to enlarged lymphoid follicles?
Follicular conjunctivitis
What are the four layers of the cornea?
Epithelium
Stroma
Descemets membrane
Endothelium
What are the characteristics of the corneal epithelium?
Physical barrier to tears, micro-organisms, environment
Hydrophobic
Doesn’t have blood vessels in health
Has nerves
What are the characteristics of the stroma?
Hydrophilic
Stays relatively dehydrated through the action of the endothelium (sodium/potassium pumps) and epithelium (passive)
What is stromal overhydration called?
Corneal oedema
What is the anterior chamber?
The space between the cornea and the iris
What fills the anterior chamber?
Aqueous humour
What are the characteristics of the aqueous humour?
Fills the anterior and posterior chambers
Maintains intra-ocular pressure
Feeds the inner cornea
Produced from blood fluids by the epithelium of the ciliary body
What two diseases can affect the anterior chamber?
Uveitis increases uveoscleral outflow and decreases IOP (intra-ocular pressure)
Glaucoma due to iridocorneal angle closure/clogging
What relationship exists between IOP and glaucoma/uveitis?
Uveitis = decrease in IOP Glaucoma = increase in IOP
What are the parts of the uvea?
Anterior uvea made up of the iris and ciliary body
Posterior uvea which is the choroid
What are the common denominators of the uvea?
It is a mesh of blood vessels and usually contains a lot of pigment
Other than blood vessels what else does the anterior uvea have?
Muscles - constrictor and dilator
Anterior blood ocular barrier that separates blood and aqueous humour
Other than blood vessels what else does the posterior uvea have?
Tapetum lucidum
What is miosis?
Iris spasm resulting in pain
What does endothelial cell separation into the anterior chamber result in?
Keratic precipitates
Hyphema
Fibrin
Proteins
What is leakage of blood components seen as around the lens?
Snow banking
What are adhesions of the iris to the anterior lens called?
Posterior synechia
What are PIFMs?
Pre-iridal fibrovascular membranes
What can PIFMs result in?
Bleeding in the eye due to uveitis
Closure or blockage of the iridocorneal angle
What is rubeosis iridis?
Anterior uveitis of the uvea
What can cause redness of the anterior uvea?
PIFMs
Hyphema
Keratic precipitates
What can sudden decompression result in?
Inflammation
Anterior synechia (iris to cornea)
Bleeding from the iris and ICA due to retrograde flow of aqueous humour followed by blood
What can cause sudden decompression?
Corneal perforation
Iris and lens damage
What is the posterior uvea?
It is the choroid and is continuous with the anterior uvea
What can diseased posterior and anterior uvea present as?
Posterior and anterior uveitis
Bleeding into the anterior segment of the eye (hyphema)
Retinal detachment
How can the retrobulbar area become red?
Inflammation and infection
Neoplasia
How can inflammation and infection get to the retrobulbar area of the eye?
Haematogenously
Nerves
From the eye
Which structures of the eye can become neoplastic?
Muscle, fat, nerves, blood vessels, cartilage, glands, skin
What do retrobulbar area problems lead to?
Altered position of the eye in the orbit and relationship with eyelids
Possible increased pressure around the eye
Swelling or infection of the tissues around the eye
Vision loss
Pupillary problems
Restriction of ocular movement
What are the first steps of the ophthalmic exam?
Symmetry
Tear test
What are the three main light examination techniques and what are they used for?
Distant direct - retroillumination, cataracts vs sclerosis
Close direct - fundus, retina, high magnification
Indirect - fundus, retina, low magnification
What are some ancillary tests used in the ophthalmic exam?
Tonometry
Imaging
Fluorescein
Gonioscopy
What does DAMNITV stand for?
Degenerative/developmental Anomalous/autoimmune Metabolic/mechanical/mental Nutritional/neoplastic Inflammatory/infectious/ischaemic/inherited/iatrogenic/idiopathic Traumatic/toxic Vascular
