Retina Flashcards
What are the effects of epiretinal membrane (ERM) and its treatment?
Effects of ERM
● Cystoid macular edema (CME) → occurs due to tractional forces exerted by ERM on retinal blood vessels running through nerve fiber layer
Treatment
● Vitrectomy with membrane peel +/-internal limiting peel
● Removing internal limiting membranes prevents recurrence of ERM
What is central areolar choroidal dystrophy?
● Autosomal dominant
● Mutations in peripherin/RDS gene
● Onset -middle age
● Electrooculography and electroretinography are normal
● Normal choroidal flush
● Visual acuity ranges from 20/25 to 20/200
● Mild nonspecific granularity of fovea → slowly progresses to pathognomonic round zone of neurosensory RPE and choriocapillary atrophy
What are the electrooculography (EOG) and electroretinography (ERG) findings in Best’s disease?
● EOG abnormal
● ERG normal
What is Stargardt’s disease?
● Autosomal recessive (most common); ABCA4 gene mutation -codes for ATP binding cassette transporter protein expressed by rod outer segments → accumulation of lipofusin in RPE → limits RPE function and viability
● Diffusely “dark choroid” on fluorescein angiogram -retinal vessels are highlighted against a hypofluorescent choroid due BLOCKAGE from diffusely distributed lipofuscin. >80% have this
● Visual acuity ranges from 20/50-20/200
● Macular atrophy (beaten bronze) discrete yellowish pisciform flecks at level of RPE
● Flecks widely distributed in fundus = fundus flavimaculatus
● Vitamin A increases rate of lipofuscin pigment accumulation in RPE, so avoid!
What age does North Carolina macular dystrophy present and what is its range of visual acuity?
● Presents in late puberty
● Visual acuity ranges from 20/20-20/200
What is central serous chorioretinopathy?
● Well-delineated serous retinal OR RPE detachments
● More common in males; age 25 to 55
○ Symptomatic if macula is affected → central vision loss, metamorphopsia, hyperopic shift, central scotoma, decreased color vision
○ Most commonly bilateral and asymmetric
● Risk factors
○ Type A personality
○ Exogenous or endogenous steroids
○ Stress
○ Organ transplantation
○ Systemic lupus erythematosus
○ Systemic hypertension
○ Sleep apnea
○ GERD
○ Psychopharmacologic medications
○ Pregnancy
● Visual prognosis is good except → chronic, recurrent or bullous
● 80-90% undergo spontaneous resorption of subretinal fluid within in 3 months
○ Observe initially → if fluid persists > 3-6 months → treatment with thermal laser photocoagulation, photodynamic therapy or systemic medications
● Most common fluorescein angiogram pattern “expansile dot” pattern
● Least common fluorescein angiogram pattern “diffuse pattern”
● Fluorescein angiogram pattern “smokestack” pattern occurs in 10% of cases
● OCT macula shows serous retinal detachment, serous RPE detachment, and thickened choroid
What is the differential diagnosis for bull’s eye maculopathy?
● Cone or cone-rod dystrophies
● Hydroxychloroquine and chloroquine toxicity
● Chronic macular hole
● Central areolar choroidal dystrophy
● Olivopontocerebellar atrophy
● Age-related macular degeneration
● Ceroid lipofuscinosis
● Bardet-Biedl syndrome
● Stargardt disease
● Traumatic maculopathy
● Leber congenital amaurosis
What are the screening methods for chloroquine and hydroxychloroquine retinopathy?
Visual fields
● 10-2 SITA for non-Asians
● 24-2 or 30-2 SITA for Asians patients; toxicity often manifests beyond macula in Asians
ERG
● Multifocal ERG
Autofluorescence
● Increased autofluorescence in parafoveal or extramacular areas may precede areas of thinning on OCT. Late RPE loss appears as area of reduced autofluorescence
● Most frequent region of retina to show early damage is inferotemporal -corresponds to superonasal field defect
SD-OCT macula
● Localized thinning of photoreceptor layers in parafoveal in non-Asians; near arcades in Asian
What is the differential diagnosis for cystoid macular edema?
● Post-op cataract surgery
● Diabetes
● BRVO or CRVO
● Uveitis
● Post PRP
● Retinitis pigmentosa
● Subretinal disease
● Niacin supplementation
What is an optic pit?
● Small, hypopigmented, round, excavated colobomatous defects of the optic nerve
● Most commonly located inferotemporal
● Associations
○ Serous macular detachments (fluid contained is either liquid vitreous or CSF) occurs in 25-755 of cases → poor prognosis if left untreated
○ Paracentral or arcuate scotoma
○ Macular schisis
● Treatment
○ Vitrectomy with gas-bubble placement
What are the 5 most common indications for pars plana vitrectomy in diabetic patients?
● Non-clearing (dense) vitreous heme
● Tractional retinal detachment involving or threatening macula
● Diffuse diabetic macular edema associated with posterior hyaloid traction
● Combined tractional and rhegmatogenous RD
● Significant recurrent vitreous hemorrhage despite maximal PRP
What is the histologic definition of macula?
Region with more than one ganglion cell layers
What is the histological definition of fovea?
● Depression in the inner retinal surface and consists only of cones
● 1.5 mm diameter
What is the histologic definition of foveola?
● Central floor of fovea
● Inner nuclear layer and ganglion cell layer are absent
● 0.35mm in diameter
What is the histologic definition of umbo?
Central concavity of floor of foveola
What is abetalipoproteinemia?
Etiology
● Inability to synthesize apolioprotein B → fat malabsorption → fat-soluble vitamin deficiency (A, D, E, K), and retina and spinocerebellar degeneration
Genetics
● Autosomal recessive
● Mutation in microsomal triglyceride transfer protein
Clinical findings
● Pigmentary retinopathy
● Foul-smelling stools/fat malabsorption
● Ataxia
● Growth retardation
Work up
● Vitamin A levels
Treatment
● Supplementation of vitamin A and E
What is the most important indicator of visual prognosis in BRVO?
Extent of capillary nonperfusion → predictor of NV
What are idiopathic epiretinal membranes?
● Transparent, avascular, fibrocellular membrane on the inner retinal surface that adheres to and covers internal limiting membrane (ILM) of retina
● Always associated with posterior vitreous detachment
● 2% over age 50
● 20% over age 75
● Histologic findings: Muller cells (glial cells), fibrous astrocytes, fibroblasts, macrophages, hyalocytes, RPE
● Treatment
○ Vitrectomy, epiretinal membrane peel, ILM peel
● Cannot regrow on surface of nerve fiber layer
What is Gyrate atrophy?
Genetics
● Autosomal recessive
● Mutation of OAT gene, chromosome 10
Cause
● Elevated ornithine which is toxic to retina
Clinical presentation
● Geographic paving-stone-like areas of atrophy that coalesce to form scalloped border between abnormal and normal RPE
● Hyperpigmentation of remaining RPE
● Diffuse loss of RPE and choroid
● No retinal vessel attenuation, unlike RP
● Posterior subcapsular cataract
● High myopia
● Vision (night blindness) becomes abnormal around age 10
Treatment
● Arginine and B6 restriction
What is uveal effusion syndrome?
Definition
● Reduced transsclearal aqueous outflow → alteration in net water movement across the vitreous cavity and posterior eye wall
Etiology
● Abnormal scleral composition or thickness
Associations
● Nanophthalmos
● Scleritis
● High hyperopia
● Idiopathic uveal effusion syndrome
● Glaucoma
Clinical findings
● Abnormal episcleral vessels
● Choroidal and ciliary body thickening
● RPE alterations
● Exudative retinal detachment; ciliochoroidal detachment
● “Leopard-spot” pattern without leakage on fluorescein angiography
What is associated with Alagille syndrome?
● Cholestasis
● Posterior embryotoxon, Axenfeld anomaly
● Pigmentary retinopathy
● Congenital heart disease
● Flattened facies
What is associated with myotonic dystrophy?
● Ptosis
● Cardiac conduction defects
● frontal balding
● Christmas-tree or polychromatic cataract
● Ophthalmoplegia
● Pigmentary retinopathy
What is Charcot-Marie-Tooth disease associated with?
● Degeneration of lateral horn of spinal cord
● Distal muscle weakness or wasting
● Kyphosis or scoliosis
● Pigmentary retinopathy
● Optic atrophy
What is cystinosis?
● Autosomal recessive
● Defect in transport out of lysosomes → intralysosmal cystine accumulates
● Three forms:
○ Benign
○ Late-onset
○ Nephropathic → retinopathy is only found in this form which is not visually significant
○ All forms have corneal and conjunctival crystals
● Treatment
○ Cysteamine
What are the preferred argon laser color treatments for different retinal pathologies?
● Vitreous hemorrhage: red
● Macular edema due to diabetes or vein occlusion: green or yellow
● Choroidal neovascularization: green; red if blood present
● Coats disease: yellow
What are the risk factors for retinal detachment (RD) following cataract surgery?
● Younger age (attached vitreous)
● Vitreous loss during surgery (20-fold increase)
● Zonular dehiscence
● RD in fellow eye
● Axial length >23mm
● Male gender (PVD less common)
What are signs of intraocular copper toxicity, “chalcosis”?
● Very toxic to the eye
● Deposits in Descemet’s membrane
● Sunflower cataract
● Greenish color of iris
● Brown vitreous opacities
● Metallic flecks on retinal vessels
● Acutely toxic to retina → can lead to loss of an eye
What are the side effects of intravenous fluorescein?
● Temporary yellowing of skin and conjunctiva: All patients
● Bright orange discoloration of urine for the first 24 to 36 hours: All patients
● Nausea and vomiting: 10%
● Urticarial reactions: 1%
● Anaphylactic reaction: < 1:100,000
What is the differential diagnosis for neuroretinitis?
● Idiopathic (most common) AKA Leber’s idiopathic stellate neuroretinitis
● Sarcoidosis
● Syphilis
● EBV
● Lyme
● Histoplasmosis
● Toxocariasis
● Toxoplasmosis
● Bartonella henselae
What is associated with Bardet-Biedl syndrome?
● Macular pigment mottling
● Polydactyly
● Obese
● Intellectual disability
● Hypogonadism
● Renal failure
What are the differences between Laurence-Moon syndrome and Bardet-Biedl syndrome?
Laurence-Moon syndrome is the same as Bardet-Biedl syndrome except it has spastic paraplegia and does not have polydactyly
What is Alstrom syndrome?
● Autosomal recessive
● Tapetoretinal degeneration
● Central vision is lost early
Associations
● Obesity
● Diabetes
● Hearing loss
● Renal failure
● Dilated cardiomyopathy
Which forms of sickle cell disease result in the most serious ocular complications (i.e. tractional retinal detachment, vitreous hemorrhage)?
Sickle cell hemoglobin C (SC) and sickle cell thalassemia (SThal)
What is Usher syndrome?
● Sensorineural deafness plus retinitis pigmentosa (RP)
● 10% cases of RP
● Deafness is always congenital
What are the treatment options for cystoid macular edema associated with retinitis pigmentosa?
● Oral carbonic anhydrase inhibitors (CAIs)
● Topical CAIs
● Topical NSAIDs
What is the most common cause, presentation, and prognosis of post traumatic endophthalmitis?
Cause
● Bacillus cereus
● 25% of post traumatic endophthalmitis is due to Bacillus cereus
Presentation
● Rapid and severe course
Prognosis
● Very poor
What is a Birdshot fluorescein phenomenon?
“Quenching” of fluorescein dye → quick disappearance of fluorescein dye from retinal circulation
What is an APMPPE fluorescein phenomenon?
Blockage in early frames with diffuse late staining
What is a serpiginous fluorescein phenomenon?
Blockage in early frames but early hyperfluorescence at edges of lesions
What is a MEWDS fluorescein phenomenon?
“Wreath-like” clusters of spots associated with each retinal lesion
What is a sugiura sign?
● Perilimbal vitiligo
● Seen in convalescent phase of VKH syndrome
What are foster-fuchs spots?
Spots in the macula of pathologic myopia due to RPE hyperplasia after subretinal neovascularization or hemorrhage
Dalen fuch nodules are seen in which conditions?
VKH and sympathetic ophthalmia
What is bilateral diffuse uveal melanocytic proliferation (BDUMP)?
● Bilateral diffuse thickening of choroid
○ Reddish/brownish choroidal discoloration
● Resemble large choroidal nevi
● Associations
○ Serous retinal detachment
○ Cataracts
○ Most commonly seen in the following cancers: ovarian cancer, uterine cancer, lung cancer, colon cancer, pancreatic cancer, gallbladder cancer, esophageal cancer
What is the mechanism of mechanical light damage to retina and when is it seen?
● Absorbed light is strong enough to produce gas bubbles → result in shock wave to mechanically disrupt tissues
● Seen with YAG capsulotomy
What is the mechanism of thermal light damage to retina and when is it seen?
● Absorbed light causes rise in temperature of surrounding tissues
● Seen with PRP
What is the mechanism of photochemical light damage to retina and when is it seen?
● Biochemical reactions that cause destruction without rise in temperature
● Seen with solar retinopathy and overexposure from operating microscope
What are the ocular associations with pseudoxanthoma elasticuma (PXE)?
● Peau d’orange fundus
● Angioid streaks
● Optic drusen
● Round atrophic scars
● Vision loss due to angioid streaks from submacular hemorrhages or choroidal neovascular membranes
● Higher risk of choroidal rupture even after minor ocular trauma
What is Behcet’s disease?
Systemic manifestations:
● Recurrent oral ulcers
● Epididymitis
● Skin lesions (erythema nodosum)
● CNS involvement
● Arthritis
Ocular manifestations:
● Hypopyon
● Occlusive vasculitis
● Retinal necrosis
● Ischemic optic neuropathy
● Severe vitritis
Associations
● HLA-B51
What is Best disease?
Genetics
● Autosomal dominant
● Mutation in VMD2/BEST 1 gene
● Protein codes for bestrophin → transmembrane chloride channel located in basolateral membrane of RPE
Clinical findings
● Yolk-like (vitelliform) macular lesion in childhood and eventually breaks down into atrophic appearance
● Good VA in majority of cases
● 20% will develop choroidal neovascular membrane which reduces vision to 20/200
● Electroretinogram normal
● Electrooculogram (EOG) abnormal (Arden ratio <1.5): Abnormal pumps on RPE, although 37% with Best disease can have normal EOG
What is the gene that is mutated in Sorsby macular dystrophy?
TIMP3
What is the Geneva study?
● Randomized clinical trial, 1267 patients
● Evaluated dexamethasone (Ozurdex) intravitreal compared to sham intravitreal in eyes with vision loss due to macular edema (ME) associated with BRVO or CRVO
● Results: Ozurdex reduces risk of vision loss, improve speed and incidence of visual improvement in eyes with ME associated with BRVO or CRVO
What is the timing of retinopathy of prematurity (ROP) screening?
Dilated fundus exam 4 to 6 weeks of postnatal age or within 31st to 33rd week of postconceptional or postmenstrual age, whichever is later
What are the clinical findings most predictive of progression to proliferative diabetic retinopathy?
● Venous beading
● Intraretinal microvascular abnormalities (IRMA)
What are the most common causes of spontaneous vitreous hemorrhage, in decreasing order?
● Diabetic retinopathy
● Retinal break without detachment
● Posterior vitreous detachment
● Rhegmatogenous retinal detachment
● Neovascularization after BRVO or CRVO
What is different about the temporal nerve fibers in all forms of albinism?
The fibers decussate instead of projecting to ipsilateral lateral geniculate nucleus
What is Chediak-Higashi syndrome?
● Life threatening condition associated with albinism
● Autosomal recessive
● Mutation in lysosomal trafficking regulator in CHS1/LYST gene
● Albinism plus neutropenia
Associations
● Susceptibility to infections
● Bleeding and coagulation defects
● Ataxia
● Peripheral neuropathy
● Mucosal defects: gingivitis, oral ulcers, periodontal disease
● Many patients do not survive past early childhood
What is Hermansky-Pudlak syndrome?
“Four P’s”
Platelet defect
Pulmonary fibrosis
Puerto ricans
Pigmentless
● Life threatening condition associated with albinism
● Albinism plus platelet defect
Associations
○ More common in Puerto Rican descent
○ Pulmonary fibrosis
○ Granulomatous colitis
○ Immunodeficiency
What are the similarities and differences between AREDS versus AREDS-2 formulation?
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● AREDS reduced risk of progression from intermediate or advanced to more advanced ARMD by 25%
● 19% risk reduction in rate of moderate vision loss at 5 years
What are the clinical findings in pathologic myopia (-8.00 or more, axial length >32.5mm)?
● Foster-Fuchs spots
● Optic disc tilt
● Peripapillar atrophy
● Lacquer cracks
● Posterior staphyloma
● Atrophy of RPE or choroid
● Elongation or atrophy of ciliary body
● Lattice
● Paving-stone degeneration
● Choroidal neovascularization
● Peripheral retinal holes
What is the clinical feature suggestive of exudative retinal detachment?
Shifting subretinal fluid
What are the clinical features suggestive of rhegmatogenous retinal detachment?
● Low IOP
● Early extension from ora serrata to disc
What is retinal racemose angioma or congenital retinal arteriovenous malformation?
● Unilateral
● Non-hereditary
● No intervening capillary bed between retinal arteries and veins
● Poor vision if fovea is involved
● Risk for obstruction and neovascularization
● Rapid venous filling on fluorescein angiogram; does not leak
● Associated with Wyburn-Mason syndrome → ipsilateral vascular malformations of brain, orbit, and mandible
What is type 1 parafoveal (juxtafoveal) retinal telangiectasia?
● AKA Leber miliary aneurysm
● Occurs greater in males than females
● Unilateral
● Congenital or acquired
● Resembles macular variant of Coats disease with circinate type of exudate
● Photocoagulation treatment can be successful in resolving exudation
What is type 2 parafoveal (juxtafoveal) retinal telangiectasia?
● No sex predilection
● Bilateral
● Perifoveal retinal changes (more pronounced in temporal fovea)
○ Thickening of fovea
○ Loss of transparency with grayish appearance of fovea
○ Small telangiectatic vessels in the fovea
○ Cystic appearance of fovea
● 1/3 patients have abnormal glucose tolerance test
● Does not respond to photocoagulation treatment because leaky vessels are not predominant feature
● May respond to anti-VEGF
What is type 3 parafoveal (juxtafoveal) retinal telangiectasia?
● Bilateral
● Vision loss from retinal perifoveal capillary obliteration
● On fluorescein angiography, telangiectatic vessels are readily apparent and leak
● OCT mac with thinned central macular retina, including fovea with inner lamellar oblong foveal cavitations in which long axis is parallel to retinal surface
● Does not respond to photocoagulation treatment because leaky vessels are not a predominant feature
● May respond to anti-VEGF
What are the common features among all 3 types of parafoveal (juxtafoveal) retinal telangiectasia?
● Focal retinal gliosis and telangiectasia of capillary bed
● Vision loss from capillary incompetence and exudation
● Refractile changes (“retinal crystals”) in advanced cases
● Histologic changes: not true telangiectasia but rather structural abnormalities similar to diabetic microangiopathy with deposits of excess basement membrane within the retinal capillaries
What are the most common causes of diffuse unilateral subacute neuroretinitis (DUSN)?
● Baylisascaris procyonis
● Ancylostoma caninium
● Toxocara canis
Which retinal findings increase the risk of retinal tear or retinal detachment?
● Cystic retinal tufts
● Zonular traction retinal tufts
● Lattice degeneration
● Meridional folds
● Enclosed ora bays
● Peripheral retinal excavations
Which retinal findings do not predispose to retinal tear or retinal detachment?
● Non-cystic retinal tufts
● Cobblestone or pave stone degeneration
● RPE hyperplasia or hypertrophy
● Peripheral cystoid degeneration
What is the chance of severe non-proliferative diabetic retinopathy (NPDR) progressing to high risk proliferative diabetic retinopathy (PDR) over 1 year?
0.15
What is the chance that very severe non-proliferative diabetic retinopathy (NPDR) will progress to high risk proliferative diabetic retinopathy (PDR) over 1 year?
0.45
What is another name for birdshot retinochoriodopathy?
Vitiliginous chorioretinitis
Which conditions are associated with HLA-DR4?
● VKH
● Sympathetic ophthalmia
● Ocular cicatricial pemphigoid