Midterm I Flashcards
Where are the two groups of blood vessels in the retina located?
- superficial nerve fiber layer
2. inner nuclear layer
Where does the outer plexiform layer and outward receive its oxygen and nutrients from?
choroid and choriocapillaris
What layers usually separate in a retinal detachment?
RPE and sensory retina
What are the five methods to view the retina?
- OCT
- BIO
- peripheral funduscopy
- 3 mirror funduscopy
- Optos optimap
What is the junction of the inner and outer photoreceptor segments called? 1. What does it show up as on the OCT? 2
- photoreceptor integrity layer
2. thin red line above RPE
What does the RPE look like on the OCT?
deep red layer
What landmarks define the peripheral retina? 1. Posterior pole? 2. Midperiphery? 3
- area between vortex veins and ora sorrata
- bound by arcades
- arcades to vortex veins
What is used to push the peripheral retina into view?
scleral indentation/depression
Does the optos optomap get to ora?
no
What is the Optos Optomap not adequate at displaying?
retinal breaks
What are the ways to view the vitreous?
- direct ophthalmoscope (add plus from retina)
- fundus lens
- BIO (shadows on retina)
- slit lamp
What is the “skin” around the vitreous which is tightly attached to the internal limiting membrane of the retina? 1. Where is it absent? 2
- hyaloid
2. optic nerve head
What are the stronger hyaloid attachments of the vitreous from weakest to strongest?
- macula
- blood vessels
- around ONH (tightest posterior)
- vitreous base (at ora and a little into retina)
What is the clumping of solids during the deterioration of the hyaloronic acid that holds the vitreous together called?
condensation or floaters
What are the disorders that can lead to vitreal change in consistency and transparency earlier in life than expected?
- systemic vascular disease
- myopia over about 4-5 D
- connective tissue disorders
- inherited disorders
- trauma
What are the systemic vascular diseases that can lead to early vitreal deterioration?
- diabetes
- sickle cell anemia
- leukemia
What are the connective tissue disorders that can lead to early vitreal deterioration?
- Marfan’s
- Pseudoxanthoma elacticum (PXE)
- Ehlers Danlos
What is the number one reason for retinal break/detachment in children?
Wagner-Jensen-Stickler’s (aka Stickler’s)
What are the major changes in the vitreous over time in order from most to least important structurally?
- loss of hyaluronic acid the maintains gel-like consistency
- hyaloid atrophies
- vitreous collagen breaks down
- liquid content increases
What is the term for the hyaloid tugging on the internal limiting membrane?
vitreal-retinal traction
What is the separation of the posterior hyaloid and the internal limiting membrane called?
posterior vitreous detachment (PVD)
What is usually the last portion of the hyaloid that separates from the internal limiting membrane? 1. What is this called? 2. What does this lead to? 3
- hyaloid around optic nerve head
- complete PVD
- Weiss ring or Vogts ring
What is it called when the hyaloid falls forward toward the crystalline lens following detachment?
PVD with collapse or syneresis
What are flashes of light associated with a PVD called?
photopsia
About how long does it take for a complete PVD to occur after the first detachment occurs?
3-6 months
What do the tails of the vitreous base predispose the retina to?
retinal breaks in the periphery
What is caused by breaks in the internal limiting membrane and the proliferation of cells on its surface?
epiretinal membrane (ERM)
What are the other names for an epiretinal membrane (ERM)?
- preretinal membrane
- macular pucker
- surface-wrinkling retinopathy
- cellophane retinopathy
What cells form the epiretinal membrane?
glial, muller or RPE cells
What are the ways to “catch” a epiretinal membrane?
- patient complaints of distorted vision following PVD
2. shinning or glimmering when looking at the retina
What are the causes of ILM breaks?
- vitreo-retinal traction
- vascular disease (hypoxic atrophy)
- retinal breaks
What are the treatments for an epiretinal membrane?
- remove vitreous (vitrectomy)
2. epiretinal membrane peeled off
What can a epiretinal membrane lead to?
- metamorphopsia
- macular edema
- decrease in vision
What is a hemorrhage resulting from vitreo-retinal traction called? 1. What layers is this between? 2. Where in the retina does this typically occur? 3
- preretinal hemorrhage
- between internal limiting membrane and nerve fiber layer
- peripheral retina
What are the two possible reasons for a preretinal heme?
- vitreo-retinal traction
2. new blood vessel growth from systemic vascular disease
What should be done for a patient with a systemic vascular disorder and a preretinal heme?
refer to retinal ophthalmologist (NEVER monitor)
What is the common shape of a preretinal heme?
D-shaped or keel-shaped because of gravity pooling blood in that area of the “dome”
What is it called when the preretinal heme makes its way through the ILM, hyaloid and into the vitreous? 1. What might the doctor see upon fundus examination? 2
- vitreal heme
2. red blood or nothing at all (no retina seen)
What should be done for a patient that has a vitreal heme? 1. Why? 2
- refer (NEVER monitor)
2. large amount associated with breaks, possible significant traction, and can be retroneovscularization
What do patients often see when they have a vitreal heme?
red blood seen as sudden small shower of floaters
What is the shape of a vitreal heme? 1. What color does it turn with time? 2
- no normal shape and changes often
2. yellow then black
What is the problem that can occur from a vitreo-retinal traction that is the result of recurrent inflammatory reactions? 1. What does the patient see? 2
- transient macular edema
2. distorted vision
What are the two forms of retinal breaks? 1. What is the location in the retina that the break is often located? 2
- retinal hole and retinal tear
2. peripheral
What color is a retinal break? 1. Why? 2
- red
2. looking at choriocapillaris through full-thickness opening
What color is the choroid? 1. Why? 2
- purple-blue
2. melanin within
Is a retinal hole likely to lead to a retinal detachment? 1. Is a retinal tear? 2
- no (2-3%)
2. yes (30-50%)
What is the escape of pigment into the anterior portion of the vitreous due to the liquefied vitreous getting into the RPE and breaking the bonds between the RPE cells called? 1. What originally causes this to occur? 2
- tobacco dust or Shafer’s sign
2. retinal break
What is tobacco dust a probable sign of?
impending or active retinal detachment
What is the number one mechanism of retinal detachment?
liquefied vitreous getting into the RPE and breaking the bonds between the RPE cells
What are the two things that can surround a retinal hole?
- cuff of whiteish edema
2. RPE hyperplasia
What does a cuff of whiteish edema around a retinal hole indicate? 1. What should be done for a patient with this? 2
- vitreoretinal traction that creates intraretinal edema and mild sensory retinal detachment
- refer if edema is one disc diameter or more
What does RPE hyperplasia surrounding a retinal hole indicate?
lesion at least 3 months old