Macula Flashcards
1
Q
What makes up the macula?
A
Fovea 1.5mm
Foveola 0.35mm
FAZ
Umbo
2
Q
Which is the thinnest part of the macula?
A
Foveola
3
Q
Where is the macula located?
A
B/w superior and inferior temporap arcades
4
Q
Where is the reflex observed in the macula?
A
Umbo
5
Q
Which aspect is important for high resolution in the macula?
A
Fovea
6
Q
Which part of the macula holds no blood vessels?
A
FAZ
7
Q
What part of the macula help reduce the degradation of the image?
A
Foveola, the laterally displaced RGC
8
Q
How do we assess the macula function?
A
- VAs
- Amsler chart
- Retinal imaging and fundoscopy
9
Q
What test would indicate that the reason behind reduced vision is pathologological and not a refractive error?
A
Pinhole test
10
Q
How is an amsler chart used?
A
Monocular and at 30cm
Wearing the correct reading add for dist
Not use varis
Ask- “look at the central fixation dot and if there is any distortion or scotoma
11
Q
Whats the best way to view subtle changes of the macula?
A
OCT
12
Q
What is the most common cause of irreversible visual impairment in the UK?
A
ARMD
13
Q
What is the prevalence of AMD?
A
AMD prevalence increases with age
30% of > 75 yrs effected by AMD
4.8% >65 yrs diagnosed with Advanced AMD
Rises by 12.2% >80 yrs
14
Q
What are the risks factors?
A
- Age
- Ethnicity— Caucasian
- Genetics— 1st degree 3x risk
- Gender— Females
- Smoking— 2x
- Obesity
- Systemic HT
- High fat diet
- CVD history
15
Q
What 2 types of disease processes are there in AMD?
A
Geographic atrophy
Wet
16
Q
How prevalent of all AMD is geographic atrophy compared to wet?
A
Geographic 90%
Wet 10%
17
Q
Where is the earliest change of AMD?
A
Level of Bruchs membrane
18
Q
What is the role of Bruce’s membrane?
A
Regulating transportation of toxic metabolic waste from retina to choroidal blood vessels.
19
Q
What happens to Bruchs membrane with age?
A
BM thickens
Reduces permeability
Inhibits toxin removal
Waste products i.e. lipofusin accumulate
20
Q
What are the sxs of Dry AMD in each stage?
A
Early- Asymptomatic
Progression- Gradual deterioration in Central vision
Advanced- Difficulty with fine detail resolution
Severe cases- Aware of central scotoma
21
Q
What are the sxs of wet AMD?
A
Painless Sudden onset Blurred Distorted Central vision (metamorphosis) Unilateral
22
Q
What are the signs of AMD?
A
Drusen (hard, soft and calcified)
23
Q
If Unilateral, how likely is a px to develop wet in the fellow eye?
A
37% will develop in a year
24
Q
What is the 1st visible sign of AMD?
A
Drusen
25
What is drusen and how do they effect vision?
Waste products made up of lipids and collagen. They disrupt the orientation and organisation of RPE resulting in depigmentation and hyperpigmentation.
26
At which age are drusen common in?
50 yrs +
27
When does drusen indicative of AMD?
Size and number
28
What are the black arrows indicating
Soft drusen
29
What is this image showing
Calcified drusen
30
When is hard drusen a low risk of visual impairment?
When its without other signs
31
At what stage of AMD is geographic atrophy present?
End stage
32
What happens to the retinal tissue when there is geographic atrophy?
Reduce thickness and exposes underlying blood vessels of choroid and choriocappilaries
33
What is the hallmark or wet AMD?
Choroidal neovascularisation
34
What 2 things are the arrows pointing too and can they be referred as?
Top arrow hyperpigmentation
Bottom arrow hypopigmentation
Referred as 'pigment clumping'
35
Whats the prevelance for dry to become wet in AMD?
10-15%
36
What are risk factors for CNV and why?
Degeneration of RPE
Confluent soft and geographic
These are angiogenic stimulus which is ischaemia
37
Where does new blood vessel arise from?
Endothelial cells from choroidal capillaries
38
What is the subretinal neovas membrane referring to?
A fibrovascular membrane supporting the structure of the new blood vessel
39
What are the signs of subtle fibrobascular membrane?
Grey, green, yellow colour
Difficult to identify
Obscured by RPE, BM, SRL
May not have leakage
40
If there is no haemm but a fibrovascular membrane is spotted, what action is taken?
Urgent referral whether its suspected or confirmed. Haemm is inevitable
41
What is being shown here and when is it seen?
Disciform scar, seen on the end stages of wet AMD
42
What other signs could be seen with a desciform scar?
Retinal and subret haemm haemm and oedema. This gives the surface and irregular and elevated during ophthalmoscopy
43
In cases of dry AMD, when is referral not needed?
When the px is Asymptomatic...
...although counselling is needed about the implications to potential vision loss. 12/12 recall
44
When is referral needed for dry AMD pxs?
1. Unsure of retinal signs despite dilation
2. Symptomatic dry AMD
3. Dry related vision loss
45
What key aspects of dry AMD would the px need counseling of?
1. No licensed tx
2. Slow progression
3. Continue to deteriorate vision
4. No impact in early stages
5. Possibly develop wet
6. Make aware of wet sxs: sudden reduction in VA
7. Self monitor- Amsler chart
8. Compare vision
9. Information on modifiable risk factors
46
What 2 pigments are present in the macula that aids in protecting against free radicals?
Lutein and zeaxanthin
47
Where can Lutein and zeaxanthin be found?
In leafy greens I.e. spinach and kale
| The body cannot produce these
48
Why does the retina have a high amount of free radicals?
Its due to it high metabolic activity
49
Aside from Lutein and zeaxanthin, what other antioxidants can help protect the macula?
Vitamin c
Vitamin e
Cartenoids
50
What actions are taken for those with advanced dry AMD?
Refer to the GP
| Theyay benefit from LVAs
51
What merits an Urgent referral in AMD?
Exudative/ wet AMD...
| ...especially if sudden onset reduced vision. Even if signs are not clear
52
Where are wet AMD pxs sent and how?
Macula clinic via Fast track
53
Once wet pxs are referred, how long till they are seen by ophthalmologists?
2/52
54
If a fast track is unavailable locally what other options are there?
On call at local HES Same day
| OR Refer A+E
55
What is the primary tx for wet AMD?
Intravitreal injections (Antivegf tx)
56
Which type of VEGF is responsible for mediating the process of new blood vessels?
VEGF A
57
What are the common anti VEGF treatments called?
Ranizumab- Lucentis
Aflibercept- Elyea
Bevacizumab- Avastin
58
What are the non- AMD forms?
```
Cystoid macula oedema
Central serous retinopathy
Epiretinal membrane
Macula hole
Myopic degeneration
Hereditary macula dystrophy
```
59
Where is CMO usually located?
Sensory retinal layers AKA intraretinal layers
60
Where is the fluid from CMO originate from?
Intravascular peri foveal ret capillaries which are dilated
61
What is the sign of early stages CMO?
Reduced/Abolished reflex
62
What is the common cause of CMO?
Cataracts expansion AKA Irvine-Gass syndrome
63
What are the less common cause of CMO?
Intraocular inflammation (post uveitis >ant uveitis)
Diabetic retinopathy
C/BRVO
64
What are the sxs of advanced CMO?
Sudden
Painless
Blurred V
Distorted Central vision
65
How is CMO treated?
Resolve usually without any treatment, may need to treat underlying condition
66
Wht ate the pharmaceutical options for treatment of CMO?
1. CAI- increase fluid outflow into choroid
2. Corticosteroids- reduce inflammation
3. Laser photocoagulation- stimulate repair of BRB
67
What are the optometric management?
Depends on the cause:
Cataract- refer routinely
Vascular- Call HES for advice
Uveitis suspicion- Emergency referral same day
68
Which other condition shares the same symptoms as CMO?
CSR Central serous retinopathy
69
Where does the fluid originate from in CSR?
Fluid from choroid, break down of Outer BRB
70
What is CSR prevelance?
Males
Age 20-50 yrs
Unilateral
30% recurrent
71
How would CSR be managed?
If sxs- discuss with local HES
| Treatment unlikely as resolves spontaneously
72
How is epiretinal membrane formed?
Disruption from tractional forces in PVD causing ILM cells to proliferate and form epirtinal membrane
73
What are other causes of epiretinal membrane?
Most ERMs idiopathic
| Retinovascular/intraocular inflamm
74
What can bunched up or concertinaed ERMs lead to?
Macula hole
75
What surgery would be appropriate for a ERM?
Virectomy and membrane peel
76
What is visible sign of ERM?
Reflective shimmer around the macula
77
Wha is cellophane maculopathy?
Early stage sign in ERM that doesn't effect VA
78
How is ERM differentiated from macula pathology?
Slow progressing 12/12 to develop
79
If VA is effected in ERM, What action is taken?
Routine referral via GP
| ...if not effected than a a normal routine recall of 12/12
80
What causes a macula hole?
Vitreo ret traction which warps the fovea retinal structures. As adhesions are strong here this can cause retinal breaks
81
Where is the break in retina limited to?
Sensory layers, RPE is still intact
82
Which test would be used to determine the effected break?
Wazke-allen test- 0.5 disc diam width beam centered on the macula
A break in the beam would suggest the shape of the break
83
Who are more prone to macula holes?
Females
| Myopes
84
What are the early stages of a macula hole?
Small diam lesion
Little to see
Visible sign- reduced/absent fovea depression + red/yellow spot ring a fovea
Mild reduced VA, Blurred Vision and distortion
Sudden onset, unilateral , painless
85
When is a macula hole unlikely to resolve spontaneously?
Intermediate/ end stages
| If left untx may leave a permanent Central vision loss
86
What is dependent on the successful of the tx?
The time elapsed since inset
87
Why isnt there a treatment need for a macula hole compared to an RRD?
Slower progressing that RRD
88
What is the referral route for the different stages of the macula hole?
Ealry/interm- referral via GP (1/12)
End- routine referred
Cannot rule out diff dx- refer suspected macula hole via fast track AMD
89
How likely is it to effect the following eye?
By 15%
90
Wha is the ophthalmological management?
Relieving VRT via virectomy
91
What is the alternative to virectomy and what does it do?
Intravitreous injection of ocriplasmim- helps dissolve proteins in adhesions
92
Why is myopic degeneration considered a non AMD form?
Retina and choroid are thinned which makes them susceptible to atrophy.
93
Wha are the signs of myopic degeneration?
1. PPA
2. Chorioretinal atrophy around ONH
3. Thinned retina
4. Optoc disc tilt
5. Possibly breaks on BM
6. Excessive axial elongation
7. Washed out red/yellow colour
8. Hyperpigmentation
9. Exposed choroidal blood vessels
10. Possible similarities to end stage dry AMD
94
What are the sxs of myopic degeneration?
No sxs!
Gradual atrophy- resultant loss of LR function
Similar to dry AMD-
Gradual, painless, bilateral, asymmetric
95
What are the rare symptoms of myopic degeneration?
```
CNV
Sudden
Unilateral
Blurred
Distorted
```
96
When is myopic degeneration considered for referral?
Suspicion/sign CNV development
| VA drop.... refe routinely via GP
97
What are the hereditary macula dystrophies?
Stargardts disease-
Pattern dystrophy
Cone dystrophy
98
What are the typical sign of cone dystrophy?
Late stage- bulls eye and symmetrical in BE
99
What is indicative of a progressing cone dystrophy?
Onset adulthood
| Reduced VA and colour vision
100
Which disease falls under a vitelliform dystrophy and what are the typical signs?
Best disease
Signs- egg yolk lesion at macula
Lipofuscin build up at macula
101
How would hereditary macula dystrophy be managed?
Caution!
Reduced VA- Refer via GP
No tx
102
How can hereditary macula dystrophys be confirmed?
ERG and LVA assessment needed
103
What is this called and what is it a result of?
Petaloid
| This is fluid like cysts accumulated resulting in laterally displaced ganglion cell layer
104
What 2 aspects are being shown here?
Top arrow PED
| Bottom arrow Serous detachment
105
What is causing the distortion of the retinal layers?
ERM
