Upgrade to remove ads
Retina Pt 2 Ch 12-15
Terms in this set (104)
What are the 5 different types of retinal breaks?
Flap or Horseshoe tear, giant retinal tears, operculated holes, dialyses, atrophic retinal holes
What is a flap/horseshoe tear in the retina?
When a strop of retina is pulled anteriorly by vitreoretinal traction
What is a giant retinal tear?
A tear that extends more then 3 clock hours or 90 degrees circumferentially
What is an operculated hole in the retina?
When traction if sufficient to pull a piece of retina completely from the adjacent retinal surface
What are Dialyses?
Circumferential, linear breaks that occur along the anterior and posterior (more common) vitreous base commonly as a consequence of blunt trauma
What is an atrophic retinal hole?
It is not associated with vitreoretinal traction and has not been associated with retinal detachment
What are the the dimensions of the vitreous base?
Extends 2mm anterior and 4mm posterior to the ora serrata
Where is the vitreous firmly attached to the retina?
Vitreous base, margin of optic disc, the macula, along major vessels, margins of lattice degeneration, and at chorioretinal scars
Describe the events in a PVD:
Typically begins with shallow separation in the perifoveal cortical vitreous in which liquid vitreous enters thru a cortical tear and detaches the macular vitreous cortex. The evolving PVD can remain subclinical for years until separation from the glial disc margin (Area of Martegiani) causing a Weiss ring.
What factors increase prevalence of a PVD?
Main: Age and axial length of eye (myopia).
Others: inflammatory disease (increases liquification), hemorrhage, trauma, aphakia
What % of PVD have a Retinal Tear?
15% with acute symptomatic PVD
50-70% if associated with Vitreous Hemorrhage, 10-12% if not associated with hemorrhage
What is an ominous sign in a PVD?
Presence of a vitreous hemorrhage
What are lesions of the retina that predispose to retinal detachment?
Vitreoretinal tufts (cystic and zonular tractional), lattice degen, meridional folds (tear during PVD can occur at base), enclosed ora bays
What are vitreoretinal tufts?
Small, peripheral, focal areas of elevated glial hyperplasia associated with vitreous or zonular attachment and traction
What are the types of vitreoretinal tufts?
Noncystic, cystic, and zonular traction.
What types of vitreoretinal tufts can predispose the eye to RD?
Cystic and zonular traction
What are lesions of the retina that DO NOT predispose to retinal detachment?
Cobblestone degeneration, peripheral cystoid degeneration
What is Paving-stone or Cobblestone Degeneration?
Peripheral, small, discrete areas of atrophy (yellowish-white on appearance) of the outer retina in about 1/5 of adults over 20. Most common in inferior quadrants anterior to equator. Histologically there is atrophy of the RPE, outer retinal layers, choriocapillaris with resulting adhesions btw the remaining retina and Bruch membrane (thus why RD is exceedingly rare)
What is Peripheral Cystoid Degeneration?
Clusters of tiny intraretinal cysts in the OPL just posterior to ora serrata. Two forms, Typical (almost all adults) and Reticular (more posterior, 20% of adults and can rarely develop retinoschisis)
Prophylaxis of Retinal Tears in Symptomatic Patients:
Horseshoe/Dialysis: almost always
Atrophic hole/lattice degen: rarely
Propylaxis of Retinal Tears in Asymptomatic Patients:
Operculated: rarely, never if phakic
Atrophic Holes; Rarely
Lattice Degen: Never if phakic, high myope. Sometimes rx fellow eye, rarely if pseudo/aphakic
What is a subclinical retinal detachment?
A RD in which subretinal fluid extends more than 1 DD from the break but not more than 2 DD posterior to the equator
State the Lincoff Rules:
Rule 1: Superior Temp or Nasal RD:
In 98%, the break is within 1.5 CH of highest border
Rule 2: Total or Superior RD that cross the 12 oc meridian:
In 93% the break is at 12 oc or in a triangle with apex at ora or sides which are 1.5 CH on either side of 12oc
Rule 3: Inferior RD:
In 95% the higher side of RD indicates where break lies
Rule 4: Inferior bullous RD
Inferior bullae in a rhegmatogenous RD come from a superior break
What is Shafer's Sign?
Also called tobacco dusting or small clumps of pigmented cells in the anterior vitreous
What is the most common cause of failure to repair a RRD?
What is Proliferative Vitreoretinopathy (PVR)?
A complication of RRD in which vitreous cytokines come into contact with the RPE and stimulates it to proliferate and enter the vitreous forming fibrotic membranes which can cause secondary RD and prevent RD repair
How is PVR graded?
Grade A is characterized by the appearance of vitreous haze and RPE cells in the vitreous
Grade B is characterized by wrinkling of the edges of the retinal tear or the inner retinal surface
Grade C is characterized by the presence of retinal membranes
What is the DDX for retinal detachment?
Retinoschisis and Optic Pit Maculopathy
What quadrant is most common for retinoschisis?
Describe peripheral cystoid degeneration:
Typical Peripheral Cystoid Degeneration: present virtually all adults, extending up to 2-3mm posterior to ora. Cavities form in OPL, only complication is progression to typical degenerative retinoschisis.
Reticular Peripheral Cystoid Degeneration: almost always located posterior to and continuous with typical peripheral cystoid degeneration. Much less common. Cystoid spaces are in rNFL and may progress to reticular degenerative retinischisis.
Often difficult to clinically differentiate the two types
Describe Typical Degenerative Retinoschisis
Retina splits in the OPL, rarely extends posterior to macula. Outer layer is irregular and appears pockmarked on scleral depression, inner layer is thin and smooth in elevation. All cases have typical peripheral cystoid degeneration anterior to schisis cavity.
Occasionally small, irregular white dots (snowflakes) are present, which represent footplates of Muller cells and neurons that bridge or formerly bridged the cavity
Describe Reticular Degenerative Retinoschisis
Retina splits in NFL. Outer layer is irregular as in typical retinoschisis, posterior extension more common.
How can RD and retinoschisis be differentiated?
RD: corrugated surface, heme often present, scotoma is relative, absent reaction to photocoagulation, and shifting fluid may be present
Retinoschisis: surface is smooth-domed, heme usually absent, scotoma is absolute, reaction to photocoagulation is generally present, and shifting fluid is absent
What are the two types of Retinoschisis associated with full-thickness RD?
Type 1: Hole in outer wall only, contents of schisis can migrate out and slowly detach retina. Slow/rare progression, commonly have demarcation lines.
Type 2: Holes present in inner and outer wall. Detachments usually progress and require treatment
What are Optic Pits?
Most are unilateral and asymptomatic.
Small, hypopigmented yellow/white excavated colobomatous defects usually at inferior temporal portion of optic disc margin.
Can lead to serous detachment of macula w/ poor prognosis. OCT shows both retinoschisis and subretinal fluid.
What is a rhegmatogenous PVD?
When a rent in the posterior wall of the macular precortical vitreous pocket can allow the contained fluid to dissect posteriorly
Where does a PVD most commonly begin?
As a localized detachment over the perifovea
What are the two types of Epiretinal Membranes?
Idiopathic (occurs in about 2% older than 50, 20% older than 75). Nearly always due to PVD.
Secondary (due to vascular occlusions, uveitis, trauma, surgery, retinal breaks)
How does an Idiopathic ERM form?
Sometimes, as a result of immune system response to protect the retina, cells converge in the macular area as the vitreous ages and pulls away in posterior vitreous detachment (PVD). PVD can create minor damage to the retina, stimulating exudate, inflammation, and leucocyte response. These cells can form a transparent layer gradually and, like all scar tissue, tighten to create tension on the retina which may bulge and pucker (e.g. macular pucker), or even cause swelling or macular edema.
What is vitreomacular traction syndrome?
Persistent attachment of of the vitreous to the macula can elevate the macula resulting in visual distortion
What causes Idiopathic Macular Holes
Thought to be due to tractional forces associated with perifoveal vitreous detachment (thus reason why they are more common in women and myopes as these have more PVDs)
What is stage 0 of a Macular Hole?
Occurs when a perifoveal vitreous detachment develops and only subtle changes in macular topography can be observed. Usually does not progress
What is Stage 1 of a Macular Hole?
Symptoms include central vision loss and metamorphopsia.
Stage 1a: Loss of foveal depression associated with a small yellow spot and pseudocyst or horizontal splitting on OCT
Stage 1b: Yellow ring seen and progression of pseudocyst to include a break in the outer foveal layer
What is Stage 2 of a Macular Hole?
Progression of the foveal schisis (pseudocyst) to a full-thickness dehiscence as a small tractional break develops in the inner layer roof (< 400 um in diameter)
What is Stage 3 of a Macular Hole?
A fully developed hole (> 400um in diameter) typically surrounded by a rim of thickened and slightly elevated retina. Posterior vitreous may be detached from fovea but remains attached to optic disc
What is a Stage 4 Macular Hole?
A fully developed hole with complete PVD (evidenced by a Weiss ring)
What is a Mittendorf dot?
Anterior remnant of hyaloid artery as a small, dense, white, round plaque attached to posterior lens capsule
What is a Bergmeister Papilla?
A fibroglial tuft of tissue extending into the vitreous for a short distance at the margin of the optic nerve head
What is a prepapillary vascular loop?
Normal retinal vessels that have grown into Bergmeister's papilla before returning to the retina (mostly arterial)
What is Persistent Fetal Vasculature (PFV)
Originally known as Persistent Hyperplastic Primary Vitreous results from failure of the primary vascular vitreous to regress. Two types: Anterior and Posterior
Describe Anterior PFV
The hyaloid artery remains and a white vascularized fibrous membrane is present behind the lens. Signs include
, shallow AC, and
elongated ciliary processes
. Can cause lens swelling with cataract and secondary angle closure glaucoma.
Must differentiate from Retinoblastoma (both cause leukocoria) but Rb is more commonly bilateral, usually not present AT birth, and almost never associated with micropthalmos or cataract
Describe Posterior PFV
A stalk of tissue emanates from optic disc and courses toward the retrolental region. Usually has a clear lens.
What are Hereditary Hyaloideoretinopathies?
Group of conditions that result in liquefaction of the vitreous resulting in an optically empty cavity except for thin layer of cortical vitreous behind the lens and threadlike, avascular membranes that run circumferentially adhering to the retina
What is Wagner Disease?
A hereditary hyaloideoretinopathy with only ocular symptoms. AD and associated with myopia, strabismus, and cataract
Not associated with RD
What is Stickler Disease?
A hereditary hyaloideoretinopathy with systemic manifestations.
Mutation in Type II Procollagen causing myopia, POAG, cataract, midfacial flattening, pierre robin malformation (cleft palate, micrognathia, and glossoptosis), joint hyperextensibility, and arthritis.
High incidence of RD and all breaks should be treated prophylactically.
What is Familial Exudative Vitreoretinopathy?
Failure of the temporal retina to vascularize and is phenotypically similar to ROP. Frequently bilateral. Babies are full term and have normal respiratory status.
Mutation in NDP protein (similar is Norrie disease)
What is Asteroid Hyalosis?
Minute white opacities composed of calcium phospholipids in the vitreous.
Unilateral in 75% of cases. FA can be used when view in back is poor.
What is Synchesis Scintillans?
Numerous yellow-white, gold, or multicolored cholesterol crystals in the vitreous and AC (asteroid does not have AC involvement). Usually bilateral and in younger patients.
Occurs almost exclusively in eyes that have had repeated trauma or surgery causing large vitreous hemorrhages.
What are the 4 main types of ocular trauma?
Blunt - no break in eyewall
Penetrating - entrance break only
Perforating - entrance and exit break
Intraocular foreign Body
What are sequelae of Blunt Trauma?
Angle recession, hyphema, vitreous hemorrhage, RT/RD, subluxed/dislocated lens, commotio retinae, choroidal rupture, macular hole, avulsed optic nerve, scleral rupture
What are the two most common areas of scleral rupture during blunt trauma?
At the limbus or parallel to and under the insertions of the recti muscles (where sclera is the thinnest)
What intraocular materials are commonly inert as foreign bodies?
Stone, glass, sand, porcelain, plastic, and cilia
What intraocular materials are commonly reactive as foreign bodies?
Zinc, aluminum, copper (very toxic, prompt removal required), iron
What metal is especially toxic to the eye?
Copper as it causes acute chalcosis and deposits in tissues.
Describe the ERG changes with siderosis:
Iron is especially toxic to RPE and photoreceptors. Initially causes increased a-wave, later leading to diminished b-wave and eventually undetectable ERG
What organism is a common cause of post-traumatic endophthalmitis (and rare in other types)?
What % of eyes develop sympathetic ophthalmia after penetrating injury?
1 in 500
When does sympathetic ophthalmia most commonly present?
3-12 months after injury
What mechanisms help prevent against light damage to the eye?
Pupillary constriction, light absorption by melanin, and antioxidants such as leutin and zeaxanthin in the macula
Describe Solar Retinopathy:
Retinal damage caused by direct or indirect viewing of the sun. Can also be caused from occupational exposures (welding).
Patients report decreased vision, central scotomas, dyschromatopsia, metamorphopsia, micropsia, and frontal or temporal headache within hours of exposure. Most patients recover but residual effects may remain.
Characteristic finding is a yellow-white spot in the fovea bilaterally, which subsequently changes into a reddish dot often surrounded by a pigment halo.
What is Bardet-Biedl Syndrome?
A ciliopathy (defect in microtubule-based intracellular transport) resulting in obesity, polydactyly, hypogonadism, cognitive disability, macular pigment mottling (w/o bone spicules) and peripheral retinal atrophy.
What is Usher Syndrome?
AR, defect in ciliary cells causing congenital RP and sensorineural hearing loss.
What is the ERG in Duchenne Muscular Dystrophy?
Negative waveform (large a, reduced b) similar to congenital stationary night blindness but they have no visual deficits.
What is Familial Juvenile Nephronophthisis?
AR, a retinal-renal dysplasia leading to juvenile renal failure from corticomedullary cysts and tubulointerstitial fibrosis.
Retina shows pigmentary retinal degeneration that may be sectorial.
What is Gardner Syndrome?
AD, mutation in APC gene causing FAP.
Pts have colonic polyps, osteomas, sebaceous cysts, and in retina small, ovoid, multiple and bilateral pigmented lesions (similar to congenital hypertrophy of the RPE but smaller and more ovoid)
What is Incontinentia Pigmenti (Bloch-Sulzberger Syndrome)?
Rare X-linked disorder that causes death in males but in females causes dermopathy (
) involving eyes, teeth, and CNS.
Symptoms include skin pigmentation in lines/whorls, alopecia, dental abnormalities,
retinal pigmentary abnormalities
deficient retinal vascularization leading to tractional RD
What is Paraneoplastic Retinopathy?
A cancer expresses antigens that cross react with similar ones found in the retina. Type types:
Cancer-Associated Retinopathy: Rapid progressive loss of peripheral and central vision, photopsias, ring scotomas Antibody is against recoverin. Arteries are severely constricted and pigment may be absent.
Melanoma-Associated Retinopathy: Vision loss and night blindness with negative ERG (large a, reduced b)
What are the two main types of Albinism and their inheritance?
Ocular (x-linked recessive).
What are the two types of ocular involvement in Albinism?
1) True albinism - Congenitally subnormal Va (usually < 20/100) and nystagmus due to foveal hypoplasia
2) Albinoidism - Normal or minimally reduced Va without nystagmus.
Both have photophobia, iris TIDs, and hypopigmented fundi.
What two conditions need to be ruled out in Albinism?
Chediak-Higashi Syndrome (albinism with immunodeficiency)
Hermansky-Pudlak Syndrome (albinism and platelet defect causing bruising/bleeding, mostly puerto ricans)
What is Neuronal Ceroid Lipofuscinosis (Batten Disease)
Accumulation of lipopigments (ceroid, lipofuscin) leads to neuronal cell death causing progressive dementia,
, vision loss, and pigmentary retinopathy (optic atrophy,
macular pigment changes (bulls-eye maculopathy)
with mottling of the fundus periphery, and reduced or absent ERG).
What is Abetalipoproteinemia?
Lack of apolipoprotein B leading to fat malabsorption, fat-soluable vitamin deficiencies, and retinal/spinocerebellar degenerations
Supplementation with vitamins A and E is needed
What is Zellweger Syndrome?
A leukodystrophy with absent peroxisome function leading to retinal degeneration, hypotonia, seizures, renal cysts, hepatic fibrosis, and infant death
What is Refsum Disease?
A leukodystrophy with impaired peroxisomal breakdown of phytanic acid (due to absent alpha oxidation of branch chain fatty acids)
Causes pigmentary retinopathy, reduced ERG, cerebellar ataxia, polyneuropathy, anosmia, hearing loss, and cardiomyopathy, and night blindness.
Diagnosis is by elevated plasma levels of phytanic acid, treat with dietary restriction of phyctanic acid precursors.
What Mucopolysaccharidoses cause retinal dystrophy?
Ones with heparan sulfate storage deficiencies.
MPS 1 H Hurler Syndrome/ MPS I S (Scheie Syndrome) - coarse facies, cognitive disabilities, corneal clouding, and retinal degeneration. AR
MPS II (Hunter Syndrome): XR. Pigmentary retinopathy w/o corneal clouding.
MPS III (Sanfilippo Syndrome): Severe pigmentary retinopathy
What is Tay-Sachs Disease?
Most common lysosomal storage disease.
Caused by lack of hexosaminidase A, causes ganglioside buildup in neurons leading to cognitive disability, blindness with "cherry spot red" and death btw 2-5 years.
Describe Gaucher Disease
A lysosomal storage disease
Large accumulation of glucosylceramide, can have cherry spot red or whitish subretinal lesions
Describe Niemann-Pick Disease?
A lysosomal storage disease
Causes buildup of sphingomyelin
50% have cherry spot red and macular halo can be present
Describe Fabry Disease?
X-linked, mutation in alpha-galactosidase A causing ceramide trihexoside accumulation.
1st symptom is usually burning paresthesias in extremities in childhood, can also have corneal verticillata (whorls), tortuous conj vessels, tortuous and dilated retinal vessels, and lens changes.
Intralysosomal cystine accumulates because of a defect in transport out of lysosomes. Cysteine crystals can develop in cornea/conj in all types but retinopathy only occurs in types with renal involvement (rarely causes significant visual probs however)
What type of cystinosis has retinal involvement?
Only the nephropathic type
What are characteristics of the mitochondrial disorders?
Progressive external ophthalmoplegia, ptosis, pigmentary retinopathy, ERG changes
Kearns-Sayre Syndrome can have heart block and thus referral to cardio is required
Describe Chloroquine Toxicity:
Signs include bilateral, paracentral visual field changes (best detected with red test object) and subtle, granular depigmentation of the paracentral RPE. With continued exposure bull's-eye maculopathy develops.
At what daily and total doses does retinal toxicity with Chloroqine and Hydroxychloroquine usually develop?
Risk of toxicity develops after cumulative doses of 1000g of hydroxychloroquine and 460g of chloroquine.
Doses above 6.5mg/kg/day for hydroxychloroquine and above 4mg/kg/day for chloroquine can be toxic (weight is lean body weight)
In what tissues are phenothiazines concentrated?
RPE and uveal tissue by binding to melanin granules
Describe the effects of the phenothiazines (chlorpromazine and thiordazine)
Chlorpromazine: abnormal pigmentation of the eyelids, conjunctiva, cornea, anterior lens capsule. Pigmentary retinopathy is rare.
Thiordazine: rapid pigmentary retinopathy can develop. Over time retinopathy evolves to widespread patchy atrophy of the rpe and choriocapillaris (image).
What are retinal findings with Tamoxifen use?
Rare but can develop a crystalline retinopathy and sometimes macular edema
What are retinal findings with canthaxanthine use?
Canthaxanthine is artificial tanner and can cause a crystalline retinopathy
What can IV infusion of desferrioxamine cause?
Rapid, bilateral vision loss (within 7-10 days of treatment) with nyctalopia, ring scotoma, and reduced ERG repsonses.
Fundi can appear normal initially developing widespread mottled pigmentary changes within several weeks.
Return of baseline vision usually occurs over 3-4 months
What has rifabutin been associated with?
Anterior and posterior uveitis
What symptoms can isotretinoin cause?
Reversible poor night vision
Abnormal dark adaptation cursed and ERG responses are seen.
What symptoms can digitalis cause?
Blurred vision, pericentral scotoma, defective color vision, and xanthopsia (yellow vision).
Due to effect on cone system which reverses with cessation of the drug
What symptoms can sildenafil cause?
Transient blue tinting of vision and temporary abnormal ERG response
What are the causes of crystalline retinopathy?
Primary hereditary hyperoxaluria
Secondary oxalosis from CKD
Talc (from IV drug use)
Ethylene glycol ingestion
Bietti crystalline dystrophy
THIS SET IS OFTEN IN FOLDERS WITH...
Retina Pt 2 Ch 4-7
Retina Pt 2 Ch 8-11
Retina Pt 1
Uveitis Pt 1
YOU MIGHT ALSO LIKE...
Peds Pt 4
Uveitis Pt 2
Pathology Pt 2
BLOCK 104 U2
OTHER SETS BY THIS CREATOR
COCO Course Retina Part 2
COCO Retina Course Part 3
COCO Course Retina Part 4
COCO Course Retina Part 1