Disease Profiles: Retina and Choroid Flashcards
What is a stage I macular hole?
Foveolar detachment
Which patient group is most likely to be affected by chorioretinitis?
Immunodeficient patients e.g. HIV/AIDS
What is indicated by the arrows?
Posterior vitreous detachment
Which patient group is most likely to develop central serous chorioretinopathy?
Men 30-50 years
Describe the pathophysiology of a exudative non-rhegmatogenous retinal detachment
Subretinal fluid accumulation without retinal tears
Can be caused by e.g. choroidal tumours, intraocular inflammation etc.
What is a retinal hole?
Hole in the retina caused by chronic retinal atrophy
How would you investigate chorioretinitis?
Swab - culture (bacterial/viral), serology for toxoplasma and toxocara
Describe the management of posterior vitreous detachment
No treatment necessary - symptoms improve as brain as brain adjusts
Describe the clinical presentation of an epiretinal membrane
Metamorphopsia
Decreased acuity
What causes a macular hole?
Idiopathic
Secondary e.g. due to vitreous detachment, trauma
Describe the management of retinal tears
Management of retinal tears aims to create adhesions between the retina and the choroid to prevent detachment
This can be done using laser therapy or cryotherapy
What is toxocaranis (roundworm)?
Form of chorioretinitis involving ingestion of toxocara eggs (parasite hosted by cats and dogs) - leads to systemic and ocular infection
Reactive inflammatory processes lead to the organism’s encapsulation and the formation of eosinophilic granulomas, which can cause irreversible visual loss if the egg has migrated to the eye
Describe the fundoscopy findings associated with central serous chorioretinopathy
Roundish detachment of central retina
Define pathological myopia
Type of myopia that begins during childhood and progressively worsens, resulting in severe myopia by adulthood with an axial length >/= 26mm or refractive error >/= -6.00D)
Define non-rhegmatogenous retinal detachment
Detachment without any retinal tears - can be tractional or exudative
Describe the findings associated with pathologic myopia on fundoscopy
Lacquer cracks
Subretinal haemorrhage
Fuschs’ spot
Posterior staphyloma
RPE/choroid atrophy
Degeneration - cystoid, paving stone, lattice
Describe the management of chorioretinitis
May involve observation or antimicrobials ± topical steroid treatment - depends on causative pathogen and other criteria
Describe the clinical presentation of central serous chorioretinopathy
Hyperopia
Metamorphopsia
What causes chorioretinitis?
Usually a response to viral, bacterial, fungal or protozoal infection
What is an epiretinal membrane?
Scar tissue formation across the inner surface of the retina which can cause visual problems
What is a stage II macular hole?
Full-thickness defect <400µm
What causes pathologic myopia?
Environmental and genetic influences cause increased axial growth of the eyeball so image focus is too far ahead of the retina - blurred vision
Often accompanied by degenerative changes in the retina
What is a stage III macular hole?
Full thickness defect >/=400µm with no posterior vitreous detachment
Name two complications of posterior vitreous detachment
Can predispose to patients developing retinal tears and retinal detachment
What causes the formation of an epiretinal membrane?
Scar tissue most commonly forms due to age-related vitreous retraction
Can also form following eye surgery or inflammation inside the eye
What causes floaters in posterior vitreous detachment?
Collection of deposits in the vitreous body of the retina perceived as spots or strings drifting through the visual field
What is a stage IV macular hole?
Full thickness defect >/=400µm with posterior vitreous detachment
What is the most common finding in fluorescien angiography of a patient with central serous chorioretinopathy?
Small, focal hyperfluorescent RPE leak
Describe the findings on fundoscopy associated with rhegamogenous detachment
Retinal tear may be visible
Detached retina takes a convex shape
Deep mobile elevation extending to ora serrata (junction between retina and ciliary body)
Slightly opaque with dark blood vessels
Loss of choroidal pattern
Patients with retinal detachment may describe a curtain/shadow descending or ascending on field of vision. What does the shadow correspond to?
Area of detached retina
What is toxoplasma gondii?
Protozoa which can cause chorioretinitis
Congenital or acquired
Usually results in a mild flu-like illness and rarely causes any further problems, but in immunocompetent patients it enters latent phase with cysts forming and can reactivate
Describe the management of pathologic myopia
Annual checkups if stable
If CNV develops - anti-VEGF
What is a macular hole?
Central small break in the macula
Name the most common cause of retinal detachment
Rhegmatogenous - tears or holes in the retina leading to detachment
What is a retinal break?
Full thickness defect in the sensory retina
What is acute retinal necrosis?
Form of chorioretinitis caused by HSV/HZV
Describe the clinical presentation of chorioretinitis
Older patients commonly present with reduced visual acuity with floaters, usually unilateral symptoms which develop over a few days
Congenital infections may present insidiously, with little history and few symptoms
Define posterior vitreous detachment
Detachment of the posterior vitreous cortex from the internal limiting membrane of the retina
Define central serous chorioretinopathy
Serous retinal detachment at the posterior pole of the eyeball (macula or perimacular region) due to a defect in the pigment epithelium which allows fluid to leak from the sclera into the subretinal space
Describe the management of retinal detachment
Various sugical procedures which aim to reattach the retina and reduce any traction or pressure that may cause it to detach again
How would you investigate viteomacular traction?
Optical coherence tomography
How would you manage a sight-threatening Toxoplasma gondii infection?
Systemic treatment -clindamicin/azithromycin +/- steroids
Define vitreomacular traction
Incomplete posterior vitreous detachment with the persistently adherent vitreous exerting tractional pull on the macula and resulting in morphologic alterations and consequent decline of visual function
Define chorioretinitis
Inflammatory and exudative condition of the choroid and the retina (form of posterior uveitis)
What is a retinal tear?
When a retinal break is associated with vitreous traction (PVD), it is termed a retinal tear
What causes posterior vitreous detachment?
Age-related degeneration of the vitreous body (most common cause)
Myopia
Eye injury
Describe the fundoscopy findings associated with an epiretinal membrane
Retinal striae
Subretinal fluid or cystic damage
Almost always associated with PVD
Define rhegmatogenous retinal detachment
Tears or holes in the retina leading to detachment
Requires acute posterior vitreous detachment and predisposing peripheral retinal degeneration
Discuss the risk factors for rhegmatogenous retinal detachment
Posterior vitreous detachment
Pathological myopia
Previous intraocular surgery
Trauma
What examination findings might you see in retinal detachment?
May have RAPD
Describe the clinical presentation of a macular hole
Metamorphopsia
Central visual field losses
Severe reduction of visual acuity
Describe the clinical presentation of viteomacular traction
Metamorphopsia
Decreased vision
Describe the clinical presentation of pathologic myopia
Slowly progressive vision loss, scleral thinning
Define retinal detachment
Refers to the detachment of the inner layer of the retina from the retinal pigment epithelium
Describe the findings on fundoscopy associated with non-rhegamogenous detachment
Detached retina takes a convex shape
Smooth elevation
May be very mobile deep with shifting fluid
Subretinal pigment (leopard spots) after flattening
No retinal tear visible
Which investigation us used to evaluate patients with pathologic myopia for development of choroidal neovascularization?
Fluorescein angiography
Name the two types of retinal detachment
Rhegmatogenous and non-rhegmatogenous
What is posterior staphyloma?
Outpouching of scleral tissue typically involving the optic disc or macula, seen in pathologic myopia
What is Fuschs’ spot?
Degeneration of the macula; occurs due to proliferation of RPE associated with choroidal haemorrhage, seen in pathologic myopia
What causes photopsia in posterior vitreous detachment?
Caused by partially detached vitreous tissue pulling on the retina
Describe the clinical presentation of posterior vitreous detachment
Usually asymptomatic
Photopsia with eye movements
Floaters
Describe the fundoscopy findings associated with a macular hole
Depending on the stage, a subfoveal spot or ring can be noted
In more advanced cases, a partial or full-thickness macular break is observed
Describe the management of an epiretinal membrane
Surgery indicated if patient has significant visual complaints of visual decline and /or metamorphopsia
Describe the pathophysiology of a tractional non-rhegmatogenous retinal detachment
- Formation of vitreoretinal bands (most commonly due to proliferative diabetic retinopathy)
- Pressure on the band during eye movement or as a result of sudden decrease in intraocular pressure
- Retinal detachment
Describe the clinical presentation of retinal detachment
Painless, progressive visual field loss
Patients may describe a curtain/shadow descending or ascending on field of vision
If detachment affects macula, central vision will be lost
Sudden onset of floaters/flashes can proceed visual loss - indicates posterior vitreal detachment
Describe the clinical presentation of a retinal tear/hole
Asymptomatic
May have photopsia or see floaters
What is endogenous chorioretinitis?
Very rare form of chorioretinitis caused by bacteria or fungi (50/50)
Associated with bacterial endocarditis or indwelling catheters including central lines
