1. SDL 21: Eye Disorders

2. Uvea/Uveitis  Uvea is composed of the iris, ciliary body, choroid  Choroid: lotsa vascular tissue, no lymphatics  Uveitis: inflammation of..you guessed it: ciliary body, choroid, or iris.  Systemic or localized  Usually in anterior segment (i.e. juvenile RA)  Uveitis is usually associated with retinal pathology  Commonly by Pneumocystisis jirovecii  Other idiopathic causes could be autoimmune or sarcoidosis  Cytomegalovirus: think AIDS pts.

3. Uveal Melanomoa  Metastases to the choroid can commonly lead to uveal melanoma, the most common intraocular malignancy in adults.  Probably due to excessive exoposure to UV radiation during childhood. Not proven tho.  Usually spread hematogenously  commonly to liver metastasis I will give you uveal melanoma!

4. Characteristics  Microscopically, we see spindled or epitheloid tumor cells.  Lots of tumor-infiltrating lymphocytes=adverse outcome.  Unlike cutaneous melanomas  Extraocular extension of tumor: poor prognosis  Might also notice:  Retinal detachment  Glaucoma  Enucleation or radiation: no survival benefit. 

5. Retina and Vitreous  Retina is developed from the diencephalon  Responds to injury via gliosis  Hemorrhages of the nerve fiber layer appear as horizontal flames or streaks.  Retinal surface hemorrhage: appear as dots.  Retinal Detachment: separation of neurosensory retina from retinal pigmented epithelium  Could play a role in hereditary retinitis pigmentosa Hem. Nerve fiber layer Hem. Retinal surface

6. Vitreous Humor  Clear gel that fills space between retina and lens.  Adult form is avascular  Can be opacified due to trauma or retinal neovascularization  Creates “floaters” in vision Trauma neovascularization

7. Retinal Detachment (more)  Could develop after the vitreous collapses structurally  Liquefied humor can seep through the tear and get bt the neurosensory space and the pigmented epithelium  Reattachment: release vitreous traction by indenting sclera  Sugery: Sclera buckling or vitrectomy Scleral buckling vitrectomy

8. Retinal Vascular Disease  Normally, one can see blood flow in retina  Hypertension arteriosclerosis copper silver color  In retinal arteriosclerosis, arterial walls are thickened and blood appears more copper or silver color  Malignant hypertension: probably more severe retinal and choroid vessel damage  The occlusion may lead to infarcts of the retinal nerve fiber layer  Axonal damage can occur and axoplasmic transport can get interrupted  Therefore, we get accumulation of mitochondria and swollen axon ends  Cytoid bodies!

9. Retinal Vascular Disease  In ophthalmoscope, one would see a “cotton wool spot.”  May also see this in AIDS pts. Cytoid bodies: think Malignant HTN or AIDS pts Swollen axons with accumulation of mitochondria

10. Diabetics.  Hyperglycemia possibly lead to cataracts  Diabetes can also lead to microangiopathy  Types of retinal vasculopathy seen in diabetics:  1. Background pre-proliferative: abnormal angiogenesis of retinal vessels  General diabetic retinopathy, retinal basement membrane vessels are thickened.  Microaneurysms are most important concern  Hemorrhages  Breakdown of retinal blood barrier  Macular edema  visual loss.  Occlusion of vessels  up-regulation of VEGF cataracts Microaneurysms! Macular edema

11. Diabetics.  Proliferative diabetic retinopathy: neovascularization of the optic nerve  Can lead to neovascular glaucoma: if the trabecular meshwork and iris adhere together  Occlusion of main outflow (canal of Schlemm) Diabetic retinopathy: multiple hemorrhages present.

12. Retrolental Fibroplasia  Aka retinopathy of prematurity  Low birth weight infants, treated with oxygen, immature temporal retinal vessels may constrict and leave tissue downstream ischemic.  Up-regulation of VEGF  Temporal retina may be dragged to periphery, pulling the macula laterally. Could lead to retinal detachment. Tempora retina Periphery Lateral Macula Retinal detachment!

13. Retinal Artery And Vein Occlusions  General vascular disorders can affect central retinal artery  Atherosclerosis-narrow vessel walls  predisposed to thrombosis  Thrombi in Central retinal a. can develop from carotids or heart.  Hollenhorst plaques: plaques lodged in retinal circulation  Can lead to retinal infarct.  Retinal vein occlusion with ischemia: can lead to retinal neovascularization or angle closure glaucoma

14. Age-Related Macular Degeneration (ARMD)  Either non-neovascular (atrophic or dry) or neovascular (exudative or wet)  Pts over 75  (70%) hereditary  Not sure which genes, but maybe CHF (complement factor H)  BIG risk for those with CHF CC genotype + smoking 10 pack years history  Choroidal neovascularization:  Angiogenic vessels originating in the choroid capillaries.  Can settle underneath retinal pigmented epithelium after penetrate Bruch’s membrane.  May settle underneath neurosensory retina, leak and leave macular scars. VEGF antagonist injections have been used to treat the affected eye. + CHF-CC genotype

15. Retinitis Pigmentosa  Not inflammatory, it is a collection of inherited retinal disorders.  X-rec, auto dom, auto rec  Genes affected are resp. for regulating function of photoreceptor cells or retinal pigmented epithelium  RP can develop in isolation or maybe with Refsum disease  Lose cones=visual acuity affected  Lose rods=night blindness  Constriction of retinal vessels, retinal atrophy, and optic nerve head atrophy present also.  Retinal pigment is left around the vessels also

16. Retinal Lymphoma  Similar to primary large cell lymphomas of the brain  Older patients  Present similar to uveitis  Dx depends on findings of vitreous aspirate Aspirate! Dx Lymphoma

17. Optic Nerve Pathology  Neoplasms of the optic nerve are similar to brain.  Most common are gliomas (pilocytic astrocytomas) and meningiomas  Partial interrupted blood flow: vision loss, where complete loss of blood flow: optic nerve infarct  Interrupted blood flow:  Arteritic AION: inflammation of vessels surrounding optic nerve  Non-arteritic AION: embolitic or thrombotic events  Bilateral vision loss can be from temporal arteritis…just treat em with corticosteroids

18. Papilledema  Edema of optic nerve head (typically bilateral)  From raised CSF or possible tumah  Nerve head and axonal transport swells as venous stasis occurs due to increased concentric pressure.  CN II swelling can lead to elevated intracranial pressure  Increased intracranial pressure: probably no vision loss

19. Glaucomatous CN II Damage  Some pts with glaucoma actually have normal intraocular pressure: normal tension glaucoma  NTG is from nerve fiber layer thinner and ganglion cell loss.  Found by using optical coherence tomography  Advanced cases, CN II is cupped and atrophic NTG: thin nerve fiber layer and ganglion cell loss

20. Other CN II Neuropathies  Leber Hereditary Optic Neuropathy…possible nutritional deficiencies like tobacco alcohol ambylopia or methanol  Young men  Mitochondrial gene mutations? + environmental factors  CN II degeneration  Optic neuritis  Lose vision after demyelinated CN II  Think of MS pts.  Those who get optic neuritis are actually at risk for developing MS.  Single episode: may recover and be totally fine.