ocular pathology Flashcards
(24 cards)
ocular pathology?
Ocular pathology is the study of diseases affecting the eye, including their causes, mechanisms, clinical features, and effects on vision.
What are the primary causes of ocular disease?
Genetic factors
Infectious agents (bacteria, viruses, fungi)
Environmental factors (toxins, UV exposure)
Vascular diseases
Immune system dysfunction
Trauma or injury
How does vascular disease affect the eye?
Diabetic retinopathy: Caused by microaneurysms, hemorrhages, and retinal ischemia due to chronic high blood sugar.
Retinal vein and artery occlusion: Caused by blockage in retinal vessels, leading to vision loss, edema, and retinal ischemia.
What are the most common types of cancer that affect the eye?
Retinoblastoma: Malignant tumor of the retina, typically diagnosed in children.
Ocular melanoma: Cancer of the pigmented cells in the uvea.
Metastatic cancers: Breast, lung, and skin melanoma are the most common cancers that metastasize to the eye.
What is the pathogenesis of diabetic retinopathy?
Hyperglycemia damages retinal blood vessels, leading to microaneurysms, capillary leakage, and neovascularization in the retina, which can cause bleeding, retinal detachment, and vision loss.
What is retinopathy of prematurity (ROP), and what are its causes?
ROP is an eye disorder that affects premature infants, where abnormal blood vessel growth occurs in the retina due to immature retinal vasculature and exposure to high oxygen levels in incubators.
What are the key clinical features of uveitis?
Red eye, pain, photophobia (sensitivity to light), and blurred vision.
It can involve different parts of the uvea: anterior uveitis (iris), intermediate uveitis (vitreous), and posterior uveitis (choroid, retina).
What is uveitis, and what are its common causes?
Uveitis is inflammation of the uvea (the middle layer of the eye), caused by autoimmune diseases (e.g., sarcoidosis, juvenile arthritis), infections (e.g., herpes, toxoplasmosis), or trauma.
What are the clinical features of macular degeneration?
Loss of central vision, blurred vision, and distorted vision (metamorphopsia).
Dry macular degeneration involves gradual retinal thinning, while wet macular degeneration involves the growth of abnormal blood vessels under the retina.
How does ocular melanoma present?
Ocular melanoma often presents as a pigmented mass on the choroid or ciliary body. Symptoms include visual changes, blurred vision, and field defects due to tumor growth or retinal detachment.
What is retinoblastoma, and how is it diagnosed?
Retinoblastoma is a malignant tumor of the retina in children, typically presenting as a white reflex (leukocoria) in the pupil. Diagnosis is confirmed with fundus examination, ultrasound, and genetic testing.
What are the common symptoms of ocular tumors?
Visual changes, including blurry vision, field defects, or distorted vision.
Red eye, pain, and photophobia can also be present if the tumor involves inflammation or retinal detachment.
How is ocular melanoma treated?
Treatment options for ocular melanoma include radiotherapy, laser therapy, and in severe cases, enucleation (removal of the eye).
What is the role of the immune system in ocular diseases?
The immune system can cause inflammation and damage to ocular tissues in diseases like uveitis, ocular graft rejection, and autoimmune-related conditions like Sjögren’s syndrome.
How does neovascularization contribute to vision loss in diseases like diabetic retinopathy?
Neovascularization leads to the formation of fragile new blood vessels in the retina that can rupture, causing hemorrhage, scarring, and retinal detachment, ultimately leading to vision loss.
: What are the major risk factors for developing ocular cancers?
Genetic mutations (e.g., retinoblastoma gene for children).
UV radiation exposure (especially for ocular melanoma).
Metastasis from cancers like breast or lung cancer.
What is papilledema, and what causes it?
Papilledema is optic disc swelling caused by increased intracranial pressure, often due to conditions like brain tumors, hydrocephalus, or intracranial hemorrhages.
How does retinal vein occlusion affect vision?
Retinal vein occlusion causes retinal swelling, hemorrhages, and macular edema, leading to blurred vision and, in severe cases, vision loss.
What is the difference between wet and dry macular degeneration?
Dry macular degeneration involves the gradual thinning of the retina and drusen formation.
Wet macular degeneration involves the growth of abnormal blood vessels under the retina, leading to retinal bleeding and vision loss.
describe the term ‘aetiology’?
Underlying cause of a disease (e.g. The environment can be an underlying aetiology of disease)
describing necrosis?
it results in the cell undergoing lysis
examples in both embryonic and adult life where apoptosis is
necessary to take place for healthy functioning?
(embryonic life) –
* Sculpting of embryonic form
* Developmental organization of the nervous system
* Elimination of dangerous components of the immune system
* Elimination of excess cells if organs are too big during development
(adult life) –
* On stimulation by T-lymphocytes
* In response to DNA damage or abnormality, e.g. by radiation, viral infection or transformation
* In certain organs and tissues, on withdrawal of supporting hormones
* Mammary glands of breast following lactation
* Reduction in size of prostate gland in the case of taking testosterone
cellular changes that occur during cell death via apoptosis?
- Chromatin condenses and migrates to nuclear membrane.
- DNA is broken down into smaller units
- Cytoplasm shrinks without membrane rupture
- Blebbing of plasma and nuclear membranes
- Cell contents are packaged in membrane bounded bodies, internal organelles
still functioning, to be engulfed by neighbouring cells - Markers appear on plasma membrane, attracting phagocytes to come and
engulf the cell
State two diseases that can occur due to ‘too little’ apoptosis taking place?
Cancer, atherosclerosis
