Retina And Vitreous Flashcards
(96 cards)
1
Q
What is the vitreous made up of?
A
- Water (98%)
- Collegen
- Hyaluronan
- Combo of other materials
2
Q
Whats another name for the vitreous core?
A
Vitreous cortex and hyaloid membrane
3
Q
4 facts about the vitreous
A
Its the bulk of the globe
Provides structural support
Shock obsorber
Visoelastic
4
Q
What are the vitreous attachment and their order of strongest attachment?
A
- Vit base (strongest)
- Post Lens
- Optic Disc
- Macula
- Vessels
5
Q
What is the function of the hyaloid artery?
A
Connects blood supply of optic nerve and anterior eye
6
Q
What is pointed at here?
A
The hyaloid canal or cloquets canal
7
Q
What 2 aspects are being pointed at here?
A
Top arrow: Mittendorf dot
Bottom arrow: hyaloid artery
8
Q
Whats another name for a persistent hyaloid artery?
A
A bergmeister papilla
9
Q
What are the potential signs symptoms that can arise with a mittendorf dot?
A
Signs: Circular opacity attached to posterior lens. Similar to PSC
Sxs: No sxs, may have reduced VA if close to visual axis
10
Q
What happens to the vitreous with age?
A
Liquefaction process- becomes less gel more fluid
Shrinkage process- liberation of small collegen fibrils from vit
11
Q
What is the shrinkage and liquefaction called?
A
Liquefaction= Synchesis Shrinkage= Syneresis
12
Q
When are fibril floater most visible?
A
Bright and plain background
13
Q
What are signs of a healthy vitreous degeneration
A
Gradual onset
Longstanding
Bilateral
14
Q
What part of the vitreous detaches from the retina?
A
Posterior hyaloid membrane
15
Q
What aspect remains intact in PVD?
A
Anterior hyaloid membrane and ora serrata
16
Q
What is vitreous ret dehiscence and causes it?
A
Seperation of vitreous from reti a allowing vit to collapse centripetal
Cause: weakening of vitreous ret interface with age
17
Q
What will catalyse the detachment?
A
Perforation which allows fluid to leak b/w ILM and post vit which will enlarge the spaces
18
Q
Where does PVD start?
A
Macula region
19
Q
What is a partial detachment?
A
Attachments between retina and vitreous remain intact elsewhere
20
Q
When is PVD complete?
A
When its detached from the ONH
21
Q
What is shown here and how does it occur
A
A weiss ring- occurs when vit detaches from the ONH
22
Q
What is an anomalous PVD?
A
Vit degeneration without detachment
23
Q
What is residual adherence?
A
Adherence between vit and retina become under strain due to the ocular mobility
24
Q
What can anomalous detachment lead to?
A
Vitreo ret traction which then leads to tears
25
What are the risk factors to PVD?
1. Age (80-90 yrs= 86%
2. Myopia- 4-5x earlier
3. Gender- Females 2-3x
4. Ocular Trauma- Cataract extraction (76%)
26
How long after would a PVD occur post cataract surgery?
1 week to 1-2 yrs
| Mean time- 7 months
27
What are the sxs of PVD?
1. Painless
2. Flashes
3. Floaters
28
What are the signs?
1. Floaters
2. Weiss ring
3. Crumpled vit (partial- crumpled milky white, comlete- empty space
29
Where are the flashes more commonly perceived by the patient?
Temporal VF
30
Aside from eye movements, what else cause traction as part of anomalous PVD?
Vit haemmorage
31
What are the signs of vit haemm?
1. Fresh well defined edges
| 2. Obscured blood vessels
32
What are the sxs of vit haemmorage?
1. Sudden
2. Small dark floaters
3. Red floaters/mist
4. Blurred vision/ cloudy vision
5. Reduced VA
33
What other vit haemm causes are there?
Proliferative DM retinopathy
| Ocualr trauma
34
What is the incidence of tears and retinal detachment in non diabetic pxs?
Tears- 70%
| Retinal detachment- 40%
35
When is PVD managed by optoms without a need for referral?
Benign- no complications meaning no tx required
36
When is an emergency referral required for PVD?
1. If increase or change in sxs alone
| 2. PVD Complicated by vit haemm
37
If the optom is unable to see the px, what is done in these cases?
Px goes to A+E
38
Following a PVD what most commonly develops and and long after?
Retinal breaks/tears- develops within 6 weeks
39
What sxs are suggestive of a retinal break/tear?
1. Increase in numeber of floater size
| 2. 'Curtain/shadow/cobweb' develops on part of the VF
40
What assessment is needed to rule out any tears breaks or detachment?
Dilated fundus exam
41
Which is the most common form of retinal detachment out of the 3 major forms?
Rhegmatogenous RD
42
What is the cause of Rhegmatogenous RD?
Formation of breaks in the retinal tissue. This leads to influx of fluid under the retina
43
Which layers separate in a Rheg RD?
Neurosensory retina from the Retinal pigment epithelium layer
44
How does the Rheg RD occur?
Smooth continual retinal tissue must be perforated by break. The tension b/w the detaching post vit and ILM can cause the retina to tear
45
What is the estimated acute and sxs PVDs that will lead to Rheg RD?
7-13%
46
What keeps the RPE and NSR together?
Weak mechanical forces- microvilli
47
Where does the fluid accumulate in Rheg RD?
Subretina
48
What the risk Factors of Rheg RD?
1. Fellow eye
2. +ve Fam Hx
3. PVD- (Acute, sxs, gradual, increased tension, vit haemm, incomplete PVDs)
4. Age
5. Myopia
6. Ocular trauma
7. Ocular surgery (Cat)
49
Which occupations are more at risks of RRD?
Boxers
50
How are 60 year old compared to <30 year olds likely o develop RRD?
20x more likely
51
What is the incidence of RRD?
6.8/100,000 people/ year in 25-44 yrs 69.5/100,00 people/ year in 75-84 yrs
52
How likely are myopes to develop RRD?
Low myopia= 3x
High myopia= 10x
Increase of Axial length by 1mm= risk increases by factor of 1.3x
53
What is likely risk of RRD post cat surgery?
0.68-0.9%.... usually develop within 1st 12/12
54
What are the sxs of RRD?
1. Flashes and Floaters
| 2. Acute onset
55
What are the signs of RRD?
1. VA- Unaffected if macula on
2. Pupils -ve RAPD usually (extensive= +ve RAPD)
3. IOP- compare with effected eye
4. VF- Peripheral VF defects
5. Tobacco and shafers sign (Ant vit)
6. Retinal breaks and tears
56
What VF assessment would be suitable for a peripheral defects?
Confrontation method
57
If a positive shafers sign is present, what are the chances of a retinal detachment?
95%
58
What comprises of the neuro sensory layer?
ILM including the PRL. Tears are only through the neurosensory layer only
59
What is being shown here?
Shafers/Tobacco dust- small dark brown RPE cells
60
Where are breaks are commonly found?
Superior temporal 60%
61
What is a common type of tear?
A horse shoe or u shape. (The black arrow
62
How would you manage a px with tobacco dust?
TB dust but no tear- an emergency opinion
63
What signs require emergency referral to ophthalmologist?
1. Vitreous haemm
2. +ve shafers sign/tobacco dust
3. Retinal break, tear or hole
4. Retinal detachment
64
What is the gold standard to check for detachment in the most periphery?
Goldmann 3- mirror lens
| (A sclera indentation may be required with this)
65
What are the different types peripheral Ret degeneration?
1. Lattice
2. Snail track
3. White c pressure
4. Other peripheral ret deg
a. Paving stone
b. Microcystoid
c. Honeycomb
66
Which is the most common and important peripheral degeneration?
Lattice deg
67
Where is lattice more commonly found?
Myopes
pxs with RRD
Areas with thin/Absent ILM
68
Why are breaks typical found in the superior temporal periphery?
Vitreous and retina are particularly strong over lattice areas. This increases tension which increases risk of retinal break
69
What is the distinguished feature of lattice deg?
Sclerosed blood vessels- hardened vessels that appear white. Cause is uncertain
Also feature hyperpigmentation
70
What to do if patient shows ASYMPTOMATIC lattice degeneration?
No referral needed. Give information about RD sxs and advise emergency eye exam if sxs present.
71
What are the college of optometrists guidelines for pxs with lattice deg?
Refer as emergency- lattice deg and sxs of PVD/RD even if signs are normal
72
What is the 2nd most important peripheral degeneration?
Snail track
73
Where is a snail track located?
Around the equator and young myopes
74
What are the signs of snail track?
Band of white frost like dots
75
What is being shown here?
White s pressure- areas are usually demarced
76
What is being shown here?
Paving stone deg
77
Which other retinal degeneration have no increased risk of RD?
Paving stone
Microcystoid
Honeycomb
78
Which degeneration allows you to see choroid blood vessels?
Paving stone
79
What is the typical location of paving stone degeneration
Inferior retina
80
What vitreous degeneration are there?
1. Asterois hyalosis
| 2. Retinoschisis
81
What are the signs of asteroid hyalosis?
Pale yellow white lesions (calcium lipid deposits)
Unilateral ~75%
Move/float c eyemovements- can cause visual sxs
'Snow globe'
Elderly ~3%
82
What are the signs of retinoschisis?
```
Smooth dome shaped elevation Hypermetropes
Bilateral
Asymptomatic
F+F absent
No tension
NSL elevated
Common in inferior retina
May have small white dots
```
83
What causes retinoschisis?
Aggregation of microcyst in layers causing a split in OPL. This serveres connection between PRL and RGC
84
What is the prevelamce of retinochisis?
5-7% adults
85
What is the 2nd most common RD?
Tractional
86
What is tractional RD associated with?
1. Proliferative diabetic retinopathy
2. Retinal venous obstruction
3. Prematurity retinopathy
4. Sickle cell retinopathy
( ALL link to retinal ischaemia which contributes to vitreoretinal membranes)
87
What is not associated with tractional RD?
1. Tears
| 2. Tabbaco sign
88
How is Exudative RD formed?
Fluid accumulation b/w BM and RPE also known as PED
89
What causes exudative RD?
Breakdown of the outer BRB which regulates flow of blood constituents b/w choroid and outer retinal layers
90
How is the outer BRB broken down and what conditions are responsible?
Inflammatory or retinovascular conditions:
a. Post uveitis
b. Post scleritis
c. Intra ocular or retro Bulbar tumours
d. Infections I.e. tuberculosis and syphilis
91
What is the ophthalmological management for retinal detachments?
REFER! Same day phone call
92
When calling the hospital, what information should we give to HES staff?
Case history info-
Is vision effected
When change in vision was noticed
Time scale between loss and F+F
93
What are the aim for surgical treatment?
Reattach NSR to RPE by - sealing breach, draining subret fluid and providing force c NSR and RPE
94
How long would a macula 'ON' px would be seen for a surgery?
24-48 hours
95
What surgical interventions are there?
Scleral Buckle
| Pars Plana Virectomy
96
In scleral buckle how are breaks sealed?
Laser and cryotherapy
