Ocular Pathology Flashcards
What is sympathetic uveitis ophtahlmia?
Bilateral diffuse granulomatous inflammation
T- cell mediated panuvieitis that occurs after a penetrating eye injury
Blurred vision, photophobia in the non-injured eye
What are mutton fat keratic precipitates?
Granulomatous uveitis
Collectino of epithelioid cells plus lymphocytes macrophages, multinucleated giant cells or pigment on the endothelium of the cornea
What are Dalen Fuch’s nodules
RPE inflammation with accumulation of macrophages in sympathetic uveitis
Uveal reaction to antigens localised on the RPE
What is phacoanaphylactic endophthalmitis?
Autoimmune zonal granulomatous inflammation caused by rupture of the lens capsule and consequent reaction to the lens material
May result from the breakdown of tolerance at the T cell level and formation of an antibody and antigen reaction
Macrophages an dlymphocytes enter the antioer chamber from dialted vessles in iris and ciliary body.
What is phacolytic glaucoma
Macrophages engulf lens matter and can block the AC angle leading to phacolytic glaucoma
What is suppurative endophthalmitis
Tissue necrosis with PMN leukocyte infiltration
Exogenous sources - srugical, penetrating, radiation, chemical
Endogenous - BEhcets inflammation, haematogenous spread
What is non-suppurative uveitis and enophthalmitis?
Inflammation (anteiror, intermediate or posteiorr)
Exogenous - traumatic anteiror uveitis - blunt trauma, penetrating injury inducing sterils inflammation
Endogenous - idiopathic inflammation associated with viral, bacterial infection or local ocular disease, ifnlammation associated with systemic disease
What is sjogren’s syndrome
Primary or secondary to systemic disease
Disorder of acinar glands of conuunctiva, lacrimal gland and oral mucosa
Glands destroyted by a lymphocytic infiltrate
Loss of conjunctival goblet cells leading to impaired tear secretion and dry eyes
What is rheumatoid eye disease?
Immune complex and T cell mediated mechanism
Wide spectrum of eye effects
What is necrotising scleritis and peripheral corneal ulceration due to?
Immune complex deposition which leads to complement activation, PMN infiltration, collagenase production and corneal melt
What is corneal melt
Spontaneous central-periphaerl corneal ulceration with or without infalmmaotry cell infiltrate
What is scleromalacia perforans
Thinning of the sclera and exposure of the underlying uveal tract
What happens in TED
Orbits become congested, swollena nd painful
More commonly bilateral
Dry eye due to corneal exposure, conjunctival chemosis, proptosis, eyelid retraction, lid lag, superior limbal keratopathy, diplopia, compressive optic neuropathyha
What is the histology in TED
Perivascular lymphocytic infiltration with mast cells and glucosaminoglycan accumulation within and around the EOM and fat
This progresses to fibrosis
What are effects of blunt trauma?
Separation of attachments - e.g. ciliary msucle attachemnt to scleral spur - angle recession glaucoma
Retinal oedema or commotio retinae - retinal vessel spasm producing ishcaemia and endothelial damage or interruption of axoplasmic flow in the ganglion cell processes.
Shearing of photoreceptors leading to a reactive RPE proliferation and pseudoretinitis pigmentosa
What wavelenghts do the cornea and lens absorb?
UV and blue wavelengths
What does laser stand for
Light amplication by stimualted emission of radiation
Why is there pigmentation around laser burns
RPE proliferation at edge of burn leads to pigment around white scar formed by glial cells
What are side effects of radiation to the eye?
Endarteritis - infiltration of the vessel wall by inflammatory cells and proliferation of the spindle cells within the internal elastic lamina - contributes to tumour necrosis but can also lead to telangiectasia and leakage of plasma into surrounding tissue.
Dry eye due to lacrimal gland damage
Increased risk of mutations
Cataract formation
Radiation retinopathy
Why is alkali damage worse than acid
Acids coagulate tissue meaning diffusion through cornea and sclera is limited
Alkali pass through easily and destroy lens, uveal tract, retina
What are corneal dystrophies?
Inherited, bilateral and progressive diseases that lead to corneal opacification
Autosomal dominant with complete pentrance
What is cogan’s microcystic dystrophy
Map dot fingerprint dystrophy
AD or sporadic
Onset in 2nd decade
Degeneration of cells with cyst formation leads to unstable epithelium
Histology - thickened BM, absent hemidesmosomes, fibillary materal between BM and Bowman’s layer
What is Meesman’s dystrophy
Ibset in early childhood
Epithelial dystrophy - separation of cells leading to formation of loops of basement membrane and microcysts
What dystrophy affect Bowman’s layer?
Reis-Buckler
Fine reticular opacity in superifical cornea - fibrous tissue between Bowman’s and epithelium
Thiel-Behnke
RB TB (Bowman’s)
