Disorders of the Vitreous and Peripheral Retina

Question 1

What the four major points of attachment of the vitreous? Order them from strongest to weakest. What determines the strength of the attachment?

Answer 1

Strongest –> Weakest:

1. Vitreous Base
2. Optic Nerve Head
3. Retinal Vasculature
4. Macula

The vitreoretinal adhesion is strongest where the ILM of the retina is the thinnest

Question 2

What happens to the vitreous as we age?

Answer 2

The vitreous body is comprised of a gel matrix that begins to liquefy and derange as we age (40+). The liquefied vitreous coalesces into pockets called lacunae. Eventually, the adhesion of the vitreous to the posterior pole weakens and liquid accumulates in the retro-cortical space. This accumulation leads to a collapse of the vitreous body and eventually leads to a PVD.

Question 3

What group of people experience a change in the vitreous sooner? Myopes or hyperopes?

Answer 3

Myopes

Question 4

What is a PVD? What group(s) is/are more likely to have a PVD?

Answer 4

A PVD: Posterior Vitreous Detachment occurs when the vitreous liquefies and fluid accumulates behind the vitreous cortex and in front of the retina. This pushes the retina and vitreous apart and eventually, the force is great enough to displace the vitreous from the retina.

PVD’s occur in 85% of aphakic patients and is more common in women than men.

Question 5

What are the different kinds of PVD?

Answer 5

Complete PVD: When the vitreous is completely separated from the ONH
With collapse: When the vitreous begins to collapse due to lacunae coalescing and gravity.

Complete PVD with collapse
Incomplete PVD with collapse
Complete PVD without collapse

Question 6

How do PVD with collapse and PVD without collapse differ?

Answer 6

PVD with collapse occurs in older patients, especially myopes. PVD with collapse includes degeneration and lacunae in the vitreous. PVD with collapse has a rapid onset and also is accompanied by hemorrhages and retinal breaks in 8-15% of cases.

PVD without collapse occurs in younger patients and there are no vitreous changes. Retinal breaks and hemorrhages are rare and the onset is a more gradual, slow event.

Question 7

Why is an anterior vitreous detachment rare?

Answer 7

Because the vitreous base is the strongest point of attachment between the vitreous and the retina.

Question 8

If you see a vitreal hemorrhage accompanying a PVD, what may also be present?

Answer 8

You are worried about a retinal break being present. Retinal breaks are associated with a PVD + Vitreal hemorrhage 75% of the time!

Question 9

What are free RPE cells in the anterior vitreous a sign of?

Answer 9

Anterior vitreous detachment

Retinal detachment

Question 10

Explain asteroid bodies

Answer 10

Asteroid bodies are yellow-white granules that consist of calcium soaps that accumulate in the vitreous body. These bodies make it very difficult for us to get a look at the retina, but these patients will have perfectly normal visual acuity and quality of vision. 90% are unilateral.

Question 11

What is PHPV?

Answer 11

PHPV: Persistent Hyperplastic Primary Vitreous. PHPV is a failure of regression of the structures of the primary vitreous during development. There are anterior and posterior forms of PHPV.

Anterior: Unilateral with leukocoria. DDx: Retinoblastoma

Posterior: DDx: Retinopathy of prematurity (ROP is when a newborn is exposed to 100% oxygen)

Question 12

What are the 4 locations of retinal anomalies?

Answer 12

1. Oral Zone: Ora Serrata
2. Intrabasal Zone: Within the vitreous base
3. Juxtabasal Zone: Along the posterior border of the vitreous base
4. Extrabasal Zone: Posterior to the vitreous base

Question 13

Define Retinal Detachment.

Answer 13

Separation of the RPE from the neurosensory retina.

Question 14

What are the three types of retinal detachment? Which type(s) of retinal detachment is/are bullous? Which is most common?

Answer 14

1. Rhegmatogenous Retinal Detachment: bullous (most common)
2. Tractional Retinal Detachment: Not bullous
3. Exudative Retinal Detachment: Not bullous

Question 15

Which type of retinal detachment (Rhegmatogenous/Tractional/Exudative) is not usually found in the peripheral retina?

Answer 15

Tractional

Question 16

Explain a Rhegmatogenous Retinal Detachment.

Answer 16

A Rhegmatogenous Retinal Detachment (RRD) is the most common form of retinal detachment. RRD is a retinal emergency and there is a high probability of vision loss. The combination of peripheral breaks (NOT holes) in the retina and vitreous adhesion allows fluid to accumulate in the subretinal space (between PR and RPE). The fluid accumulation gives retina a bullous appearance and the area of the retina that is affected appears convex. Patients will report flashes of light/floaters in their vision and you may see RPE in the anterior vitreous. Once the RRD occurs, RPE hyperplasia will also occur. In an RRD that is ~3 months or older, there will be a demarcation line of pigment surrounding the detachment. If there is no demarcation line, either the RRD is less than 3 months old, or the detachment is superior and is likely still progressing.

Question 17

What are some clinical features of an RRD? (4)

Answer 17

Opaque retina: PR die once they separate from the RPE, becoming opaque
Pigment in anterior vitreous
PVD
Linear Retinal Tear

Question 18

What procedure is typically done to treat an RRD?

Answer 18

Scleral buckle reattachment

Question 19

What are 2-3 initial (2-4 months) and late post-op complications of fixing an RRD?

Answer 19

Initial:
Re-detachment
Glaucoma

Late:
Ptosis
Cataract

Both:
Cystoid macular edema
Preretinal macular fibrosis

Question 20

What color are retinal holes/tears? Why?

Answer 20

Retinal holes/tears are always red. There are fewer layers of the retina that attenuate the color of the RPE.

Question 21

Which way does the apex of a horseshoe tear typically point?

Answer 21

Towards the posterior pole.

Question 22

What is the most common retinal break?

Answer 22

Atrophic retinal hole

Question 23

What is the difference between an atrophic retinal hole and an operculated retinal hole?

Answer 23

An atrophic retinal hole will not have a chunk of tissue floating above it while an operculated retinal hole will (tissue floating is called an operculum)

Question 24

What region of the retina does an operculated hole usually occur?

Answer 24

Between the ora and the equator

Question 25

What is the most significant disorder of the retina that predisposes someone to retinal breaks/RDD?

Answer 25

Lattice degeneration

Question 26

Where is lattice degeneration usually found?

Answer 26

Inferior/superior retina

Question 27

Where are you most likely to see a vitreoretinal traction tuft?

Answer 27

Nasally

Question 28

What kind of retinal anomaly has a characteristic “fishbone” appearance?

Answer 28

Lattice Degeneration

Question 29

How does Snail-Track Degeneration differ from lattice Degeneration?

Answer 29

Snail-Track does NOT have the fishbone appearance that Lattice does.

Question 30

How do you manage an RRD?

Answer 30

Scleral buckle

Question 31

How do you manage a retinal tear?

Answer 31

Treat with laser/cryopexy if they have a history of detachment or a subclinical detachment of 1DD+. Otherwise, just monitor

Question 32

How do you manage an atrophic retinal hole?

Answer 32

Referal if symptomatic with holes, or with a subclinical detachment of 1DD+

Question 33

How do you manage an operculated hole?

Answer 33

If symptomatic with holes or with a subclinical detachment of 1DD+, if you see vitreoretinal adhesion, or if they are aphakic you should refer for a consult, otherwise monitor

Question 34

How do you manage a vitreoretinal tuft?

Answer 34

Patient ed on signs/symptoms of RD and refer if you see a retinal break with a traction tuft

Question 35

How do you manage lattice degeneration?

Answer 35

Education on signs/symptoms of RD and refer if you see breaks at the margin of the lattice or if the patient is symptomatic with atrophic holes

Question 36

How do you manage snail track degeneration?

Answer 36

Education on signs/symptoms of RD and refer if you see breaks at the margin of the lattice or if the patient is symptomatic with atrophic holes

Question 37

What is acquired retinoschisis? How does it differ from a retinal detachment?

Answer 37

The retina is splitting at the OPL or INL (Usually OPL). This split fills with fluid and will lead to an absolute visual field defect. Splitting at the OPL/INL prevents synapses from PR to be sent to the nerve. This differs from a retinal detachment because the neurosensory retina is still intact, the PR are just slowly dying, resulting in a relative visual field defect. Retinoschisis also will be transparent and will rarely present with a tear while a RD will have opaque sections of the retina and will have the tear.

Question 38

Why does Retinoschisis not have a demarcation line like a retinal detachment?

Answer 38

Retinoschisis has a split in the retina at the OPL/INL, so the RPE is not exposed, and there will be no RPE hyperplasia.

Question 39

How do you manage a retinoschisis patient?

Answer 39

It varies based on the layer where the break occurs. If the break occurs in the inner layers only you can monitor it. If the break involves the outer layers or both the inner and outer layers of the retina, you should refer for consult.

Question 40

What retinal anomalies have a high probability of vision loss? Which retinal anomalies have a moderate probability of vision loss? Which retinal anomalies have a low risk of vision loss?

Answer 40

High Risk:
RRD
Retinal Tear

Moderate Risk: 
Operculated Hole
Atrophic Hole
Lattice
Snail-Track 
Vitreoretinal Traction Tuft
Acquired Retinoschisis 

Low Risk: 
Focal Chorioretinal Atrophy 
Congenital RPE Hypertropy 
RPE Hyperplasia 
Choroidal Nevus 
White Without Pressure