Pathology of the eye Flashcards
What are the leading causes of blindness /SSI worldwide?
Leading causes of blindness /SSI worldwide;
- Cataract (leading cause worldwide)
- Uncorrected refractive error
- Age-related macular degeneration (leading cause in UK of blindness)
- Diabetic retinopathy
- Glaucoma
- Corneal opacities
80% is avoidable or treatable
What is Trachoma?
Trachoma - chlamydial infection, eyelashes turn in, brush cornea, and pacification of cornea
What is the WHO criteria of blindness?
Image
What are the Risk Factors for Cataract ?
Risk Factors for Cataract;
- Age
- Diabetes
- Trauma
- Inflammation
- Steroid use
- UV/radiation
- Congenital
Cataract surgery - burrow under and take out lens and put in a new silicone one
What are the Risk Factors for Corneal Ulcer?
Risk Factors for Corneal Ulcer;
- CONTACT LENSES (get micro-abrasions when take in and out and bacteria can get in if not sanitised correctly)
- Varicella/herpes
- Steroid drop use (increase infection risk)
- Dry eyes/ Exposure
- Trauma / Burns
Once treated can cause scar, can do corneal transplant from dead doner so can see again
What do you look for in a Retinal Reflex and what abnormalities may you find ?
Normal is ‘Red reflex’ = retinal reflex
Abnormal can be caused by anything obstructing the path of light from the front to the back of the eye
What are the causes of Retinoblastoma ?
Retinoblastoma can be seen in newborns and children. Causes are;
- Knudson ‘2-hit’ hypothesis
- RB1 - tumour suppressor gene
- Hereditary - earlier, bilateral
- Non-hereditary - later, unilateral
Every newborn gets a retinal reflection check (can be done with Arclight) and is done in a 6-8 week child check up
What are the features and causes of Diabetic Retinopathy ?
Reduced vision due to;
- Growth or new vessels; vitreous haemorrhage, tractional retinal detachment and robotic glaucoma
- Leakage of fluid from damaged vessels; macular oedema with loss of central visual acuity
Treatment;
- Lifestyle - smoking, weight, exercise
- Blood sugar / pressure / cholesterol
- Support renal function
- Laser, anti-VEGF, surgery
What is the pathogenesis of Diabetic Retinopathy ?
Don’t know just look at processes involved later and what diabetes does, specifically microvascular damage causing leaky vessels and a problem
What are the Features of Retinopathy of Prematurity ?
Retinopathy of Prematurity (ROP)
Retinopathy of prematurity (ROP) is an eye disease that can happen in babies who are premature (born early) — or who weigh less than 3 pounds at birth.
ROP happens when abnormal blood vessels grow in the retina (the light-sensitive layer of tissue in the back of your eye). Some babies with ROP have mild cases and get better without treatment. But some babies need treatment to protect their vision and prevent blindness.
- The 3rd endemic in middle-income countries
- Screening program in UK
- Will cause severe sight impairment if left untreated
- The most effective intervention you can make
- Similar pathological mechanism to Diabetic Neuropathy
(We do not discharge babies until their retina has been vascularised)
What are the features of Age-related macular degeneration (AMD)?
Age-related macular degeneration (AMD);
- Most common cause of SSI > 65 ears in high-income countries
- Two types: Dry and wet
- Symptoms: Progressive reduction in visual acuity. Metamorphopsia may suggest wet AMD
- Treatment: Prevention, rehabilitation and anti-VEGF injections
Dry AMD will have thinning and usual fovea dip
Wet AMD has blood formed
Why do we use Anti-VGEF injections?
A series of injections of anti-VEGF medicines are given into the back of your eye to stop these blood vessels growing and help control the leaking blood
What is happening in this image?
New vessels forming due to diabetic retinopathy
What is wrong with this image?
Cupped = Glaucoma
What is wrong with this image?
Pale = long term compression of optic nerve, ischemic problem or nutritional deficiency
What are the features of Glaucoma ?
Glaucoma;
- Optic neuropathy with a characteristic Visual Field defect, most commonly associated with raised intraoptical pressure
- Treatment: drops or surgery
- Patients unaware of visual field deficit until advanced disease (screen as disease in elderly)
What are the features of Swollen optic discs?
Swollen optic discs;
Pseudo swelling: - Small discs; Drusen
- Drusen are yellow deposits under the retina. Drusen are made up of lipids and proteins. Having drusen increases a person’s risk of developing AMD, and they may be a sign of AMD.
Genuine swelling; Raised ICP; SOL; IIH; Hydrocephalus
Symptoms of raised ICP: headaches, especially when bending forwards (frontal); vomiting/nausea; visual disturbance; tinnitus; confusion; pupillary abnormalities; diplopia
What are the 6 extra-ocular muscles?
2 horizontal;
- Medial rectus
- Lateral rectus
2 vertical;
- Superior rectus
- Inferior rectus
2 oblique;
- Superior oblique
- Inferior oblique
(Note the trochlear nerve decussates within the brainstem, hence the superior oblique is supplied by the contralateral trochlear nucelus)
What are the features of a 3rd Cranial Nerve Palsy ?
3rd Cranial Nerve Palsy;
- Vertical diplopia (double vision)
- eye is ‘down and out’
- Diplopia (double vision) everywhere
- Pupil dilated and ptosis
- Can be associated with aneurysm - needs urgent brain imaging and angiogram
Causes; Vasculopathic, tumour, aneurysm
What are the features of a 4th Cranial Nerve Palsy ?
4th Cranial Nerve Palsy;
- Oblique diplopia (double vision)
- Head tilt away from side of lesion
- Diplopia (double vision) worse away from side of palsy if unilateral (adduction)
- Common after head injury
- Bilateral - might be congenital
Causes; Vasculopathic, tumour, congenital, trauma
What are the features of a 6th Cranial Nerve Palsy?
6th Cranial Nerve Palsy;
- Horizontal diplopia (double vision)
- Worse in far distance
- Worse towards side of palsy if unilateral
- Bilateral - concerned that raised ICP is present
Causes; Vasculopathic, tumour, cranial pressure
Whats wrong with this eye?
Corneal ulcer with hypopyon
(A hypopyon is an accumulation of leukocytes in the anterior chamber due to severe intraocular inflammation)
Whats wrong with this eye?
Classic contact-lens related keratitis
Keratitis is the inflammation of the cornea, gives the eye a comparably reddened, irritated look.
“They both look like red eye or pink eye
What is wrong with this eye?
Cataract - advanced
What is wrong with this eye?
Proliferative diabetic retinopathy
What is wrong with this eye?
‘New vessels elsewhere” (NVE) - Proliferative Diabetic Retinopathy
What is wrong with this eye?
‘New vessels elsewhere” (NVE) - Proliferative Diabetic Retinopathy
What is wrong with this eye?
Haemorrhage fro new vessels in Proliferative Diabetic retinopathy
What is wrong with this eye?
Fibrosis with tractional retinal detachment - severe proliferative diabetic retinopathy
What is wrong with this eye?
‘Rubeoss iridis’ due to proliferative Diabetic retinopathy
What is wrong with this eye?
Diabetic maculopathy with exudates
What is wrong with this eye?
Laser treatment for proliferative diabetic retinopathy
What is wrong with this eye?
Dry AMD
What is wrong with this eye?
Wet AMD, showing intra- and sub-retinal haemorrhages as well as exudates
What is Exudate?
Exudate: A fluid rich in protein and cellular elements that oozes out of blood vessels due to inflammation and is deposited in nearby tissues. The altered permeability of blood
What is wrong with this eye?
Retinoblastoma
