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COCO Course Retina Part 4
Terms in this set (62)
What are the 5 different types of retinal breaks?
Flap or Horseshoe tear - When a strop of retina is pulled anteriorly by vitreoretinal traction
Giant retinal tears - A tear that extends more then 3 clock hours or 90 degrees circumferentially
Operculated holes - When traction if sufficient to pull a piece of retina completely from the adjacent retinal surface
Dialyses - Circumferential, linear breaks that occur along the anterior and posterior (more common) vitreous base commonly as a consequence of blunt trauma
Atrophic retinal holes - It is not associated with vitreoretinal traction and has not been associated with retinal detachment
Flap/horseshoe tear (image)
Giant retinal tear (image)
Operculated hole (image)
Atrophic retinal hole (image)
What are the the dimensions of the vitreous base?
Extends 2mm anterior and 4mm posterior to the ora serrata
What factors increase prevalence of a PVD?
Main: Age and axial length of eye (myopia).
Others: inflammatory disease (increases liquification), hemorrhage, trauma, aphakia
List the lesions of the retina that predispose to retinal detachment:
Vitreoretinal tufts (cystic and zonular tractional)
Meridional folds (tear during PVD can occur at base)
Enclosed ora bays
What are vitreoretinal tufts, what types are there, and which can predispose the eye to RD?
Small, peripheral, focal areas of elevated glial hyperplasia associated with vitreous or zonular attachment and traction
Noncystic, cystic, and zonular traction.
Cystic and zonular traction can predispose to RD
List the lesions of the retina that DO NOT predispose to retinal detachment:
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.
(almost all adults) and
(more posterior, 20% of adults and can rarely develop retinoschisis)
Which patients with retinal holes do you treat with laser?
Horseshoe/Dialysis: almost always
Atrophic hole/lattice degen: rarely
Operculated: rarely, never if phakic
Atrophic Holes; Rarely
Lattice Degen: Never if phakic, high myope. Sometimes rx fellow eye, rarely if pseudo/aphakic
State the Lincoff Rules and what are they used for?:
Used to find the break in a Retinal Detachment
: Superior Temp or Nasal RD:
In 98%, the break is within 1.5 CH of highest border
: 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
: Inferior RD:
In 95% the higher side of RD indicates where break lies
: Inferior bullous RD
Inferior bullae in a rhegmatogenous RD come from a superior break
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
Describe peripheral cystoid degeneration and the two types:
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 and Reticular 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.
: Retina splits in NFL. Outer layer is irregular as in typical retinoschisis, posterior extension more common.
How can a retinal detachment and retinoschisis be differentiated?
: corrugated surface, heme often present, scotoma is relative, absent reaction to photocoagulation, and shifting fluid may be present
: surface is smooth-domed, heme usually absent, scotoma is absolute, reaction to photocoagulation is generally present, and shifting fluid is absent
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 vitreomacular traction syndrome?
Persistent attachment of of the vitreous to the macula can elevate the macula resulting in visual distortion
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)
Describe the two types of Persistent Fetal Vasculature (PFV)
Originally known as Persistent Hyperplastic Primary Vitreous results from failure of the primary vascular vitreous to regress.
: 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
: A stalk of tissue emanates from optic disc and courses toward the retrolental region. Usually has a clear lens
What is Wagner Disease and its inheritance?
A hereditary hyaloideoretinopathy with only ocular symptoms. AD and associated with myopia, strabismus, and cataract
Not associated with RD
Hereditary Hyaloideoretinopathies: A 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 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, its inheritance, and its mutation?
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 and how can you get a better view of the retina if it is dense?
Minute white opacities composed of
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 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 two metals are most toxic to the eye and in what types of tissue do each deposit?
Copper - deposits in basement membranes
Iron - deposits in epithelial tissue
What organism is a common cause of post-traumatic endophthalmitis (and rare in other types)?
What is the most common etiology of sympathetic ophthalmia?
Pars Plana Vitrectomy
What % of eyes develop sympathetic ophthalmia after penetrating injury and when does it most commonly present?
1 in 500
3-12 months after surgery
What is Gardner Syndrome (include inheritance, enzyme defect, and signs/symptoms)?
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 Tay-Sachs Disease (include inheritance, enzyme defect, and signs/symptoms)?
Most common lysosomal storage disease.
Caused by lack of hexosaminidase A, causes ganglioside buildup in neurons leading to cognitive disability, blindness with "cherry re spot" and death btw 2-5 years.
Describe Fabry Disease (include inheritance, enzyme defect, and signs/symptoms)?
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.
Describe Cystinosis and what type has retinal involvement?
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 are ocular characteristics of the mitochondrial disorders?
What is the most important thing you should do for treatment?
Progressive external ophthalmoplegia, ptosis, pigmentary retinopathy, ERG changes
Kearns-Sayre Syndrome can have heart block and thus referral to cardio is required
Describe the ocular side effects of the phenothiazines (chlorpromazine and thiordazine)
: abnormal pigmentation of the eyelids, conjunctiva, cornea, anterior lens capsule. Pigmentary retinopathy is rare.
: 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 ocular symptoms can isotretinoin cause?
Reversible poor night vision and dry eyes
Abnormal dark adaptation cursed and ERG responses are seen.
What ocular 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 ocular symptoms can sildenafil cause?
Transient blue tinting of vision and temporary abnormal ERG response
In which situations is the red laser better for?
Due to longer wavelength it
penetrates cataracts or hemorrhage better
What two type of lenses are available for slit-lamp delivery of laser photocoagulation?
Negative-power planoconcave lens
: Provides an upright image with superior resolution but small field of view and thus good for the macula. Laster spot size generally not changed from that selected on slit lamp.
High-plus power lens
: Provides an inverted image with wide field of view but less resolution. Can magnify laser spot size depending on lens used
What is Transpupillary Thermotherapy (TTT)?
An infrared laser slightly raises the choroidal temp causing minimal thermal damage to the RPE and retina.
Not effective in AMD but useful in adjunct for tumors (choroidal melanoma)
How does PDT work?
The laser excites the drug causing the drug to release energy to surrounding O2 molecules creating ROS and free radicals which damage the endothelial cells and obliterate the capillaries
What are complications of PDT?
Mild burns during photosensitivity period (up to 48 h for verteporfin) is most common and easily avoidable.
0.7-2.2% of patients experienced severe vision loss within 7 days of treatment which could become permanent and was most common with minimally classic or occult with no classic lesions
What is the intravitreal half-life for sulfur hexafluoride (SF6) and perfluoropropane (C3F8)?
What is the time until maximum expansion for each and when does this occur?
SF6: 1 week (expands to 2x volume over 48 hours)
C3F8: 3 weeks (expands to 4x volume over 96 hours)
What is the treatment for a Macular Hole?
Treat all Stage 2 or greater holes (Stage 1 often spontaneously close).
PPV + removal of posterior cortical vitreous + intraocular gas tamponade. Can consider ILM peeling.
When is vitrectomy indicated in post-op Endopthalmitis?
If acute (< 6 weeks) onset and vision is LP or worse
If chronic and injection of antibiotics into the capsular bag or vitreous does not eliminate infection, can consider PPV with partial capsulectomy and removal of intracapsular white plaque.
Endopthalmitis Vitrectomy Study (EVS) Results:
1) No benefit from systemic atbx
2) If vision is > LP: intra vit tap and inject
3) If vision is LP or worse: vitrectomy
What are indications for drainage of a suprachoroidal hemorrhage?
Recalcitrant pain, increased IOP, retinal detachment, appositional choroidal detachments (
), associated with ciliary body rotation and angle closure.
What is the most common complication after Pars Plana Vitrectomy?
Nuclear Sclerosing cataract
What are complications of silicone oil?
Glaucoma and band keratopathy
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