DIS - Retinal Detachment - Week 8 Flashcards
Define retinal detachment, including the layers affected.
Separation/cleavage between the photoreceptors and the RPE
What does retinal detachment result in the opening of? what accummulates?
Results in the reopening of the subretinal space and accumulation of fluid in this space
What happens to the subretinal space during embryonic development?
It closes as optic vesicle invaginates to form the optic cup
Is retinal detachment sight threatening? Is it considered an ocular emergency?
Yes
List the two forms of retinal detachment.
Rhegmatogenous RD
Non-rhegmatogenous RD
Define rhegmatogenous retinal detachment. What is it held open by? What does it facilitate the spread of and where?
Results from a retinal tear/hole
Break is held open by traction
Facilitates the spread of fluid from the liquefied vitreous to the subretinal space
Where are breaks more likely with rhegmatogenous retinal detachment?
More likely within a zone of degeneration
What forms around the hole/tear in rhegmatogenous retinal detachment? What happens to this and due to what(2)?
Localised detachment (cuff)
-usually spreads towards the macula, usually by subretinal fluid
What is meant by secondary non-rhegmatogenous retinal detachment? What can it be caused by?
Retina is pulled from the RPE in the absence of a tear
-caused by major internal disturbance (trauma)
What is meant by tractional non-rhegmatogenous retinal detachment? List three causes.
Shrinkage of fibrovascular vitroretinal membrane
-diabetes, CRVO, BRVO
What is meant by exudative non-rhegmatogenous retinal detachment? What does it occur subsequent to and what is the pathogenesis?
Subsequent to a damaged RPE which permits leakage from the choroid into the subretinal space
List 5 possible causes of exudative non-rhegmatogenous retinal detachment.
AMD
CSR
Choroidal tumour
Intraocular inflammation
Toxaemia of pregnancy
What happens to the incidence of retinal detachment with age? Which age has the highest incidence?
Increases with age, most in mid-50s
Is retinal detachment more common in males, females, or equal?
More in males
Compare the incidence of retinal detachment among caucasians vs asians.
Caucasians»_space; asians
Which age group does trauma related rhegmatogenous retinal detachment tend to occur?
<50
Is there a genetic component to rhegmatogenous retinal detachment?
Yes, 2.6x greater risk if relative diagnosed
List four genetic conditions associated with rhegmatogenous retinal detachment.
Syndromic myopia
Wagner syndrome
Stickler syndrome
Erosive retinopathy
Does myopia increase or decrease the risk of retinal detachment?
Increase
Does cataract surgery increase or decrease the risk of retinal detachment? Explain.
Increases linearly over time due to vitreous structure collapse
-decreased support
Is a retinal hole considered safe once it has pigmented?
Yes
List three abnormal vitreous adhesions that are risk factors for retinal detachment.
Meridional folds
Enclosed oral bays
Granular tissue
Describe how posterior vitreous detachment is a risk factor for retinal detachment, noting which type it can cause (5).
The collapsing vitreous exerts mechanical pull on the retina, causing traction, resulting in haemorrhage or tears -> rhegmatogenous retinal detachment
Summarise the risk factors for retinal detachment (4).
Fellow eye has RD
Positive family ocular history
High myopia
Past cataract surgery
List retinal degenerations that have a high incidence of retinal detachment. Note the most important one first.
Lattice degeneration
Snail track
Snowflakes
Cystoid degeneration
Retinoschisis
White without pressure
Note which of the following degerations have an association with retinal detachment:
Pavingstone
Reticular
Peripheral drusen
None
How should lattice degenerations be assessed when suspecting retinal detachment? Include a comment on tears within the degeneration.
Search for tears/holes near the edge or outside of the lattice
Those inside the lattice are often pigmented over and safe
Is rhegmatogenous retinal detachment symptomatic?
Yes, 93% first time will have symptoms
List three symptoms associated with rhegmatogenous retinal detachment. Note the most common first.
Loss of vision/blurry vision
Shadows
New floaters
What is a strong indicator of a retinal tear?
Sudden onset (<6/52)
-most present within a week
What is essential for individuals with fewer symptoms on repeat rhegmatogenous retinal detachment?
Regular reviews
List four causes of sudden increases in floaters or new floaters.
Haemorrhage
Retinal tissue
Vitreous floaters
Pigment
What is photopsia caused by and how do patients perceive it? How long do they last and where in the visual field is it projected relative to the retina? What can initiate/worsen it?
Mechanical stimulation of the photoreceptors by traction/pressure
A yellow, white, silver arc/lightning bolt or vertical flash
Frequent but momentary
Projected into the opposite visual field
Worsened/initiated by head movement
Does photopsia recur in the same position?
Yes
What is metamorphopsia and why does it occur?
Distorted vision
-caused by the retina not being flat
What is a pre-retinal haemorrhage and what is it often near?
Vitreous traction tears retinal blood vessels
Often near retinal tears
What is a patient likely to have if they have pre-retinal haemorrhage and posterior vitreous detachment?
Rhegmatogenous retinal detachment
True or false
Posterior vitreous detachment is found in most retinal detachments and/or tears
True
What is the focus of the retina often like on fundus examination of a retinal detachment case?
Out of focus, billows forward
What are retinal folds? What happens on eye movement? Is it a sign of retinal detachment?
A sign of retinal detachment
Yellow, crinkle cut or pleated appearance
Moves with eye movement
What is a convex curve and what does its apex point towards? Is it a sign of retinal detachment?
A sign of retinal detachment
It indicates the leading edge
Apex towards the macula
How can the colour of the retina vs blood vessels be a sign of retinal detachment?
Difference in colour
Paler retina
Darker blood vessels
Are unusual tortuousity of retinal blood vessels a sign of retinal detachment?
Yes
Can visual field defects indicate a retinal detachment?
Yes a relative VF defect
What is meant by a high watermark and what is it an indication of?
Pigmentation and fibrosis along the convex edge of long-standing retinal detachment
Is retinal oedema and/or anoxia a sign of retinal detachment?
Yes
Where does the detachment spread toward with time?
The macula
Describe if RAPD can occur with retinal detachment.
Only if very extensive
-i.e. the whole eye
What is shafers sign and what causes it? What does it look like?
Tobacco dust
Comes from exposed RPE and subretinal space at the tear
-looks like little brown specks
What is the likely outcome if a patient is positive for shafers sign in symptomatic posterior vitreous detachment?
High risk tear
What does the red free filter do when assessing retinal detachment?
Shows the RPE dark, increasing contrast of the detachment
What is considered a retinal hole or tear?
Any full or partial thickness discontinuity in the sensory retina
What is a primary retinal hole?
Atrophic break without traction
Can fluid enter the subretinal space even if the hole/tear is full thicknesse?
Yes
Are all holes equally dangeroud?
No
What shape do retinal tears often have (those that break with tension)?
U or horseshoe shaped
What is considered a giant retinal tear (2)?
A break in up to 90 degrees or along the edge of the vitreous base
What is a retinal dialysis?
Circumferential tears along the ora serrata over 90 degrees
Do primary holes have symptoms?
No
Is there risk of retinal detachment with primary holes?
No
Do primary retinal holes have an operculum?
No
Do primary retinal holes have smooth or rough edges?
Smooth
Do primary retinal holes have vitreous traction?
No
When should primary and secondary retinal holes be referred?
Primary - refer if suspicious
Secondary - refer
What are two associations of secondary retinal holes?
Retinal degeneration
Vitreal degeneration
What does the presence of operculum i nsecondary retinal holes suggest? What can it proceed to?
Indicates local vitreous traction
-can proceed to retinal detachment
Are cuffs common in rhegmatogenous retinal detachment and what is it due to?
Common
-subretinal fluid
What percentage of retinal holes are secondary?
93%
What shape do secondary retinal holes tend to have (3) and do they have an overlying operculum?
Oval, round or horseshoe shaped
± overlying operculum
What is a horseshoe tear, and what does it always point towards?
Partial hole operculum
Always points to the macula (round side)
What quadrants often have secondary retinal holes the most (2)? Do these quadrants have the greatest or least danger?
Temporal/superior
-more common and greatest danger
What may be associated with secondary retinal holes?
PVD
What seven things are associated with a high risk of retinal detachment? List the three most common first.
Symptomatic horseshoe hole
Symptomatic operculated hole
Recent acute symptomatic posterior vitreous detachment
Presence of vitreous haemorrhage or shafers sign
Large tears
Tears in superior quadrants
Demographic and features
Do tears in superior quadrants spread more quickly or slowly? Explain.
Spread quickly due to gravity
Produce higher/bullous detachments
What is associated with a low risk of retinal detachment?
Asymptomatic breaks within retinal degeneration
-lattice
What is the management for retinal detachment? When is urgent referral needed?
Refer to a retinal specialist
Urgent referral if the RD is recent
What is considered an old retinal detachment and should they be referred? Explain the expected outcomes.
> 1 month - have little chance of visual recovery but still refer
What are five things that should be considered when retinal detachment is seen or suspected?
Is the macula on or off?
Extent of visual field loss
Onset
Is a tear visible
High myopia, aphakia, degenerations, disease, primary vs secondary
How are retinal holes and degenerations normally treated? What about more anterior lesions?
Laser - photocoagulation seals the break
Cryopexy for more anterior lesions
-cold metal probe against the eye
Wat is the intention of treating retinal holes? What does it prevent?
Seals off the subretinal space from the vitreous and prevents spread to the macula
What may be done if vitreous traction is still present when treating retinal holes?
Laser alone may not be enough
-may add scleral buckling procedure
List 5 complications of retinal hole treatment.
Macular pucker
Vitreous haemorrhage
PVD
Retinal tear
Retinal detachment
What is the aim of retinal detachment surgery and what are 4 things it achieves?
To reappose detached sensory retina and RPE
-reduce vitreous traction on the retina
-close retinal breaks
-prevent further spread of subretinal fluid
-facilitate reabsorption of subretinal fluid
Retinal detachment surgery has to be done before what three things occur?
Tissue death
Macula involvement
Fibrosis on or under the retina
List three surgical options for retinal detachment.
Scleral buckling
Pneumatic retinopexy
Pars plana vitrectomy
What is vitrectomy and 7 things was it originally used for?
Replacing the vitreous humour
Originally used for:
-continuing vitreous traction
-vitreous haemorrhage
-tractional RD
-more complicated detachments
-if retinal breaks not seen
-if hole/tear cant be closed by scleral buckling
Describe how scleral buckling is used to treat retinal tears. What happens to the RPE? How is the break permanently closed? What happens to the tear and the SRF?
Indenting the globe near the equator gets apposition between the retina and the vitreous
RPE is pushed/indented inwards
Permanent closure of the tear is achieved with cryopexy/laser
Chorioretinal scar around the tear forms
SRF is pumped out by the RPE
-can be removed by syringe
Following scleral buckling, within what timeframe do most detachments flatten or reattach after hole closure?
Within 24 hours
What is pneumatic retinopexy and when is it considered? When is it not considered?
Ophthalmologist in-office procedure
Injection of small volume expandable gas into the vitreous chamber
Considered for uncomplicated retinal detachments with small tears
Not considered if vitreous traction is a major factor
How is the patient positioned with pneumatic retinopexy? How long is the patient required to stay in this position for?
Positioned so that the gas bubble settles over the hole like a tamponade
-required to stay in this position until reattachment occurs, 20-30 days
What happens to IOP with pneumatic retinpexy? List two risks associated with this.
Forced very high
-ONH damage
-retinal vascular occlusions
