DIS - Myopic Pathology - Week 8 Flashcards
What percentage of Australians are myopic?
20%
Does myopia prevalence vary with ethnicity?
Yes
Is myopia a leading cause of blindness and vision impairment?
Yes
What happens to the ocular globe with myopia?
Ocular elongation and stretch
What is considered a high myope and what percentage of them have pathological changes? Can retinal pathology be associated with mild myopia?
High myopes have >6.00D
77% of high myopes have pathology
Retinal pathology can be associated with mild myopia
What percentage of high myopes have macular pathology? Does incidence increase with axial length? What about age?
7%
-incidence increases with AL/age
What is the retinal at the macula and RNFL like in a myopic eye?
Thinned
What appearance does the retina of a myopic eye generally have? Are choroidal vessels more or less visible? Does this appearance increase or decrease with age?
Tesselated/tigroid appearance
- increased visibility of choroidal vessels
- decreases with age
How does early atrophy appear in myopic eyes (colour/border) and in what percentage of high myopes?
Patchy/diffuse atrophy
-greyish/white lesions with distinct borders
-widespread yellow lesions
20-40% of high myopes
What are lacquer cracks, how do they appear, what are their borders like and in what percentage of high myopes do they appear?
Irregular pale yellow/white thin lesions branching and crisscrossing the retina
May have pigmented borders
7% of high myopes
Does choroidal vasculature tend to be visible if lacquer cracks are present?
Yes
What are lacquer cracks suggested to be (4)?
Healed mechanical breaks in the RPE, bruchs membrane, and choriocapillaris
What percentage of lacquer cracks progress?
20%
What 7 things are associated with lacquer cracks?
CRA Age Axial length Vision loss Fuchs spot CNVM Haemorrhage
What is usually seen at the ONH/macula with staphyloma?
Posterior ectasia
How does staphyloma appear (colour/margins)?
Pallor, atrophyc retina, distinct margins
Are choroidal vasculature prominent with staphyloma?
Yes
What six things is staphyloma associated with?
Progressive RD Macular holes CNVM Macular retinoschisis Lacquer cracks Vitreous abnormalities
What percentage od high myopes have staphyloma?
12-25%
List four common ONH pathologies associated with myopia.
PPA/myopic crescents
Peripapillary retinal detachment
Tilted disc
What does a tilted disc predispose you to?
Glaucoma damage
What percentage of normal eyes and high myopes have PPA/myopic crescents?
23-38% in high myopes
14% in normal eyes
What happens to the area of PPA with age and axial length?
Increases with age and axial length
What is meant by zone β and zone α in terms of location for PPA?
Zone β - clostest, complete CRA/crescent/ring
Zone α - outer, hypo and hyper
How does peripapillary retinal detachments appear (colour and location)? What is it due to and what could be used to detect this?
Tellow/orange lesions localised near the ONH
Cystoid spaces in the choroid
-OCT
What kind of traction is often seen in a tilted disc?
Supra-traction
What is the association between PVD, myopia, and axial length? Explain what ocular enlargement entails for the vitreous (2).
Develop PVD earlier with increasing myopia and axial length
Ocular enlargement associated with peripheral changes, but no significant associations with peripheral degenerations
Compare the incidence of lattice degeneration in normal eyes vs myopes.
General <10%
Myopic 25%
When does lattice degeneration develop and is it age-related?
2nd/3rd decades, not age related
Describe what lattice degeneration looks like.
Sharp bordered, white arborising/branching lines
Irregular pigment
Spiral shaped
Where are lattice degenerations often seen? Is it often bilateral?
Temporal
Often bilateral
What do the white branching lines of lattice degeneration indicate?
Sclerosed retinal vessels
What is the vitreous overlying lattice degeneration often like (2)?
Liquefied
Abnrmal vitreoretinal adhesions
What is meant by an atypical lattce degeneration? What is it possibly?
No white lines, local accumuation of snowflakes (muller remnants?)
Possibly RPE clumping only
What is the most significant peripheral retinal change in myopic pathology?
Lattice degeneration
What does lattice degeneration have a significant association with?
RD
What is a retina with lattice degeneration prone to and from what? Along what edge and when does it frequently develop?
Prone to retinal tears from vitreous traction
- typically along posterior edge
- frequently develop at onset of acute PVD
What is a snail trail thought to be?
Probably a precursor or variant of lattice degeneration
Do snail trails have similar size, shape, and distribution to lattice degeneration?
Yes
Describe what snail trails look like.
Bands of tightly packed snowflakes on the inner retinal surface, glistening or frost-like surface
What is the risk of vitreous changes, tears, and detachment like in snail trails vs lattice degeneration?
Less risk
Are snail trails often uni- or bilateral? What part of pathological myopic eyes often has them?
Often bilateral and temporal
What do snowflakes look like and with what do they have approximately the same size?
They are small white intraretinal patches
-same size as drusen
What four structures can snowflakes be often seen directly within?
Lattice degeneration
Snail track
Elsewhere in eyes with lattice degeneration
Inner retinal leaf od retinoschisis
Are snowflakes often found in multiples or single?
Most commonly multiple
What is peripheral cystoid degeneration (2) and what does it look like? Are they true cysts? Explain.
Disintegration of middle retinal layers
-glia and retina
Cyst-like intra-retinal spaces but no walls to the cysts
-not true cysts
What is peripheral cystoid degeneration typically adjacent to and how many rows?
Ora serrata, 2-3 rows of vesicles
Can cystoid spaces in peripheral cystoid degneration coalesce or do they keep separate?
They can coalesce to spread
What appearance does peripheral cystoid degeneration have with anatomy?
Honeycomb appearance
Where in the eye in peripheral cystoid degeneration very common?
Far periphery
Is peripheral cystoid degeneration usually uni- or bilateral?
Bilateral
What is the prevalence of peripheral cytoid degeneration like with age and myopia?
Increases
Define acquired retinoschisis.
Retinal splitting following peripheral cystoid degeneration
What percentage of all eyes have acquired retinoschisis?
4-5%
True or false
Acquired retinoschisis is common in hyperopes and myopes.
True
How does acquired retinoschisis appear?
Smooth transparent elevation of the retina with a beaten copper surface that glistens
True or false
There are high watermarks, movement, or folds in acquired retinoschisis
False
There are none
Describe regular retinoschisis, what it follows, and whether it is benign or sinister. Does it commonly extend beyond the equator?
OPL, splitting along that plane
Follows regular cystoid degeneration
Benign, rarely extends beyond the equator
Describe reticular retinoschisis and compare its severity to regular retinoschisis. Does it commonly extend beyond the equator?
INL or NFL - reticular cystoid
More serious, but rarely reaches the posterior pole
What is essential for acquired retinoschisis?
OCT
What does acquired retinoschisis disrupt and does it give vision loss? What happens as a result and do patients typically notice?
Disrupts retinal neurons, giving vision loss
Results in an absolute visual field defect
Patients usually asymptomatic
List two risks associated with acquired retinoschisis.
Small risk of retinal detachment or spread to the macula
What does white without pressure look like?
Semitranslucent greyish-white focal or circumferential areas
Where is white without pressure most often located?
Between the equator and the ora serrata
What kind of border does white without pressure often have (3)?
A scalloped border with a deep red margin, may be smooth
What is the cause of white without pressure (2)? Is retinal atrophy likely?
Poorly understood
Retinal atrophy unlikely
More likely to be vitroretinal degeneration/adhesion/traction
What risk is associated with white without pressure along the posterior edges?
Slight risk of giant retinal tears
What percentage of normal eyes and high myopes have white without pressure?
25% of normal eyes
85% of high myopes
What three things is white without pressure often confused for?
Shallow detachment
Hole
Schisis
What is pavingstone degeneration (2)?
Thinning of the RPE and sensory retina
How does pavingstone degeneration apear? Is it an elevation or depression?
Rows of irregularly shaped yellow patches
-depressed
What can often be seen within lesions of pavingstone degeneration (2)?
Large choroidal vessels
-but also atrophic
What is the margin of lesions in pavingstone degeneration like?
Lightly pigmented
Where does pavingstone degeneration tend to manifest?
Equator to the ora serrata
What percentage of normal eyes and myopes have pavingstone degneration? Is it benign or sinister?
Common
22% of myopes
25% of all eyes
Usually harmless
What is peripheral drusen (what layer)? Histologically, what is it similar to? Is it associated with retinal detachment?
Small yellow deposits in bruchs membrane
Histologically similar to macular drusen
Not associated with RD
What is reticular degeneration and is it uni- or bilateral? Where in the eye does it occur (2)? What pattern does it have?
Bilateral senile pigmentary change
Periphery and mid-periphery
Polygonal pattern of patchy hypopigmentation surrounded by vague pigment lines
What should be excluded if reticular degeneration is suspected?
Retinitis pigmentosa
What is retinoapthy of prematurity characterised by (3)?
Avascular peripheral retina
Dysregulation of VEGF
Pathological neovascularisation
When does normal retinal neovascularisation occur (nasal and temporal)?
Begins early 2nd trimester
Nasal - 8 months
Temporal - 10 months
What drives VEGF release during retinal vascularisation?
Relative hypoxia in the periphery
What prevents normal development of the peripheral vasculature in retinoapthy of prematurity? Explain what happens post-natally and once the infant leaves hospital.
High O2 levels in humidi-cribs
VEGF is downregulated
On O2 removal, peripheral retina is hypoxic, new vessels form at the junction between vascular and avascular retina
What infant weight is retinopathy of prematurity often found?
<1,300g
What is the involvement of optoemtry for retinopathy of prematurity (3)?
Strabismus
Myopia
Amblyopia
What is stickler syndrome a disorder of?
Connective tissue/collagen
What kind of myopia is present in stickler syndrome?
Syndromic myopua - early childhood, high non-progressuve myopia
What is the vitreous humour like in stickler syndrome?
Optically empty or with vitreous opacities
What degeneration is seen in stickler syndrome?
Lattice degneration
What two non-ocular abnormalities do individuals with sticklers syndrome have?
Facial and skeletal abnormalities
What is the most common cause of retinal detachment in children?
Stickler syndrome
What are three ocular diseases associated with stickler syndrome?
Glaucoma
Cataract
Ectopia lentis
Describe wagner syndrome and the level of myopia individuals tend to have. What syndrome is it similar to?
Erosive retinopathy
Similar to stickler syndrome but no systemic associations
Low myopia (-3.00D)
What is the vitreous humour like in wagner syndrome (30? What is this due to? What retinal structure can be seen and what happens to the fovea?
Vitreous syneresis, strands and veils -due to abnormal proteoglycans Preretinal membranes can be seen Temporal displacement of the fovea -pseudostrabismus
What is marfan syndrome a mutation to?
Fibrillin gene
How do individuals with marfan syndrome tend to look physically (limbs)?
Tall, thin, disproportionately long limbs, fingers, toes
-arachnodactyl
List 5 ocular associations with marfan syndrome.
Ectopia lentis Subluxated lens Lattice degeneration Retinal detachment Glaucoma
List three cardiac abnormalities associated with marfan syndrome.
Aortic aneurysm
Mitral valve prolapse
Dilation of the aortic root
List two syndromic conditions associated with hyperopic retinopathy.
Posterior microphthalmos
Nano-ophthalmos
What happens to the risk of angle closure glaucoma with increasing magnitude of hyperopia?
Increases
What are choroidal folds (3)? What is it associated with?
Undulations in the choroid, RPE, retina
Associated with hyperopia
-small globe
List 5 differential diagnoses for choroidal folds.
Orbital mass Autoimmune diseases ARM Lymphoma Uveal effusion syndrome
List three autoimmune diaseases that could be a differential diagnosis for choroidal folds.
Posterior scleritis
TEDs
RA
What is the pathogenesis of choroidal folds (6).
Compressive stress either external or within the choroid, bruchs membrane, or retina, causing them to buckle
What happens to the choroid with choroidal folds?
Choroidal swellng
What happens to the inner scleral wall with choroidal folds (2)?
Shrinking
Mechanical deformation
List 5 sequelae of choroidal folds if long standing.
RPE atrophy Breaks in bruchs membrane Vascular incompetence/leakage CNVM Poor systemic health
