Ophthalmoscopy Prep Flashcards
Ophthalmoscopy may be performed as part of a ….
Neurological examination
What can be viewed with opthalmoscopy?
Vasculature of the eye.
To some degree, the nerve supply.
Why is a focus wheel used?
To accomodate for any refractive error.
What is the function of the focus wheel?
Can be moved to change the strength of the lens, enabling you to focus on the internal structures.
Role of lens indicator?
Number changes as lens wheel is moved.
Should be set on 0 before starting the examination.
Hyperopia
Longsightedness.
Distant object image focused behind retina.
Hence objects appear out of focus, may cause headaches, eye strain.
Myopia
Condition where image of a distant object becomes focused in front of retina.
Causes distant objects to appear out of focus.
Why is it good practice to place your free hand on patients head, with thumb above eye?
If you get too close, forehead will touch your thumb preventing you from bumping into the patient.
What may we inspect the external structures of the eye for?
Lesions, scars, trauma, any other abnormalities.
State the structures of the eye?
Eyelids, eyelashes Lateral an medial canthus Sclera Conjunctiva Iris Cornea Pupil
Blepharitis
Causes red, swollen and itchy eyelids.
Eyelids sticky and difficult to open in the morning
Non-contagious
Stye
Small yellowish spot, most commonly caused by blocking of oil gland at base of eyelid.
Can be painful / tender to touch.
Conjunctivitis
Inflammation of conjunctiva caused by viral / bacterial infection.
Highly contagious
Pinguecula
Yellow bump on eye.
Non-cancerous growth on conjunctiva.
Does not cross over
What is used to make vessels of the eye more prominent?
Fluroescein drops.
Corneal limbus
Border of the cornea and the sclera.
Pterygium
Non-cancerous, wing shaped growth of tissue across cornea.
Patients sight may not usually be painful however eye may appear red.
Conjunctival epithelial inclusion cyst
Symptomless swelling of conjunctiva, which may reduce motility.
May be congenital, primary or secondary, due to trauma
Diffuse Iris Nevus
Appear as hyperpigmented regions of the iris with minimal disruption of normal iris architecture.
How may the red reflex be performed?
Ask the patient to fix their gaze on a distant object.
Look through ophthalmoscope (with light switched on)
Observe for red reflex and identify any areas where it is reduced or distorted.
Why is the red reflex observed?
Light reflecting back from blood rich retina.
Strabismus
Both eyes are not looking forward in the same direction
What is a common observation of the red reflex?
Reduction of bright red colour due to cataracts in one of the patients eyes.
Leukocoria
Loss of red reflex.
Abnormal white reflection from retina.
Can occur if retina lacks a tapetum lucidum.
When looking through the ophthalmascope if structures are blurry or indistinct what should you do?
Move focus wheel until image is clearer.
If images become more distorted, move the wheel in the opposite direction.
Where do retinal vessels branch from?
Optic disc into quadrants of the eye.
What colours are the veins and arteries in the eye?
Veins - burgundy
Arteries - Paler with a central silvery core with 2 outer red lines.
When examining the macula , it is important to?
Dim the light of the ophthalmoscope.
When examining the fovea it is important to?
Ask patient to look directly into the light.
Papilledema
Usually bilateral swelling of optic disc as a result of increased intracranial pressure.
Causes:
Brain tumour
Malignant hypertension
Respiratory failure
Maculopathy
Damage to macula.
- Macula is the part of the eye which provides us with central vision.
Exudates
Composed of lipid and protein.
Either hard or soft.
Often associated with adjacent fluid accumulation in the retina.
Soft exudates
Tend to be swollen nerve axons.
Age related macula degeneration
Causes vision loss in the centre of the field of vision. Drusen deposits (lipids) under retina (seen as yellow spots) are associated with an increased risk of ARMD.
2 Types of Age related macula degeneration
- Dry Macular Degeneration
2. Wet Macular Degeneration
Which is the more common type of ARMD?
Dry Macular degeneration
- Deterioriation of macula
- seen as series of dark patches
- caused by accumulation of drusen.
- causes atrophy and scaring to retina
Drusen
Deposits of extracellular waste that accumulate under the retina, between a specialized layer of cells called the retinal pigment epithelium.
Wet macular degeneration
Blood vessels grow under retina, arising from choroid or choroidal neurovascular membrane in back of eye ,leaking blood of fluid.
Describe the characteristic signs of Wet macular degeneration?
Pale patches of exudates.
Large pool of blood or lipids.
Retinopathy
Process whereby inflammation and vascular remodelling occurs over a period of time.
Types of retinopathy
- Retinopathy of prematurity ROP
- Diabetic retinopathy associated with type 1 and type 2 diabetes
- Hypertensive retinopathy
Retinopathy of prematurity ROP
, When retinal blood vessels have not developed completely as a result of prematurity.
Non proliferative retinopathy
Blood vessels in retina deteriorate.
Can become blocked, leads proteins and lipids etc
Fluid can collect in retina, impacting sharp vision
Proliferative retinopathy
New structurally unstable vessels grow on surface of retina.
Can cause frequent minor bleeding.
Hypertensive retinopathy
Results from damage to BV.
Abnormalities:
- thickening of small arteries
- blockage of retinal blood vessels
