Retinal Breaks And Detachment Flashcards
How much of the eye does the vitreous occupy and how much % is made up of water
Occupies ~80% of eye
98% water
The nasal ora serrata has more…
teeth compared to the temporal side - which provides better adhesion
what is the Interphotoreceptor matrix
the ‘glue’ between RPE and photoreceptors
there is osmotic pressure between the vitreous and…
the choroid
what is the Primary cause of retinal breaks and retinal detachment
posterior vitreous detachment
how does a pvd cause a retinal break
Traction induces retinal breaks, vitreous currents result in RD
what is the NICE guidance: Management of suspected retinal detachment from August 2019
Immediate/same day referral if
• Visual loss
• Vitreous haemorrhage or retinal detachment
Urgent referral (within 24 hours) • To a practitioner competent in the use of slit-lamp examination and indirect ophthalmoscopy to be seen within 24 hours
under what 5 conditions can you manage a patient in your practice if you confirm they have a PVD after dilated ocular examination
vision is unchanged
no retinal tear or detachment is present
no pigment is present in the anterior vitreous
the patient is well informed about what symptoms to expect if the retina does break or detach subsequently, and
you issue the patient with written information to support your diagnosis and advice
list 4 reasons for an emergency referral
retinal detachment
pigment in the anterior vitreous (tobacco dust)
vitreous, retinal or pre-retinal haemorrhage, or
lattice degeneration or retinal break, with symptoms
Approx ___% of patients with symptoms of F/F have retinal break and ___% of these breaks will progress to RD
All patients with such symptoms should have…
Approx 25% of patients with symptoms of F/F have retinal break and 50% of these breaks will progress to RD
All patients with such symptoms should have 360 indentation ophthalmoscopy
list 5 predisposing factors of a PVD
Age Refractive error Gender Contralateral eye affected Trauma and surgery
what is the Mean age of onset of a pvd
60-65 years
how does refractive error affect the onset of a pvd
5-10 years earlier in myopia
5-10 years later in hyperopia
how is gender a predisposing factor of a pvd
Male : Female ratio 2:3
females are more likely to seek medical attention
how is a contralateral affected eye a predisposing factor of a pvd
2nd eye involvement in 80-90% within 2-3 years
what type of photopsia does a person suffering from a pvd experience in comparison to a person suffering from a retinal detachment
Temporal field - White Flash with PVD
any other field associated with RD - can be coloured
Each episode lasts 1 sec or less
Resolve after 4-6 months
what 3 things can cause floaters in a PVD or RD
Aggregation of collagen fibrils
Blood
Pigment
an improvement in photopsia or floaters does not exclude…
presence of retinal breaks
how many stages are there to a PVD
5
what is stage 0 of a pvd
No detachment of cortex
describe stage 1 of a pvd
<50% Perifoveal detachment with foveal and peripapillary (ONH) adhesion
describe stage 2 of a pvd
50%+ Perifoveal detachment with foveal and peripapillary (ONH) adhesion
describe stage 3 of a pvd
Complete foveal detachment with peripapillary adhesion
describe stage 4 of a pvd
Complete foveal and peri-papillary detachment
only a small attachment on the ONH
describe stage 5 of a pvd
Complete PVD (Papillary detachment)
what is this
what 3 things can this be mistaken for
which 3 types of patients is it more common in
Vitreoschisis - splitting within the vitreous itself
PVD, ERM, VMT
Younger age, myopes, diabetic
what 4 signs do you look out for when examining a px with pvd/RD symptoms
Pigment in anterior vitreous
IOP
RAPD
Weiss opacity
which type of eyes is pigment in the anterior vitreous only applicable to when looking for signs of a RD
Only applicable to phakic eyes without previous trauma
what type of IOP should to look out for when suspecting a RD and how can this be contradictory
can be reduced if at least 1 quadrant detached (but can be
elevated!!!)
as broken photoreceptors migrate and block the trab meshwork - causing to be to elevated
what sign of the pupils should you look out for when suspecting a RD and what causes this
RAPD
if at least 1 quadrant detached, or when the macula is involved
what stage of pvd is a weiss opacity only seen in and in how many % of cases is it absent in
Only confirms vitreo-papillary separation and not peripheral vitreo-retinal separation
absent in 7-14%
how much sensitivity does a 78D and a 90D volk lens have in detecting a pvd or RD
78D - 40%
90D - 85%
how much sensitivity does a 3 mirrored lens have in detecting a pvd or RD
40-87% sensitivity
what is the gold standard viewing method in detecting a RD
BIO with indentation
how much of the retina is the FOV limited to when viewing with a volk lens
upto 124 degrees with a digital wide field
what is the sensitivity of an optimap in detecting a retinal break and a retinal detachment
33% to 70%
(vs 67% for examination)
90 -100% for RD
how many % of Operculated breaks progress into a RD
15%
how many % of a Horseshoe tear progresses into a RD
30-60%
what is the risk of progression into a RD if a tear is <1DD vs >1DD
<1DD ~5% risk
> 1DD 30% risk
what is RD pigmentation a sign of and what does it not imply
sign of chronicity and does not imply adhesion
what are the 2 most common locations of a retinal break
infero-temporal
supero-nasal
which area of the eye is associated with multiple breaks and which with a solitary break
Inferior nasal - multiple breaks
Supero temporal - solitary breaks
list 5 tx options for a RD
Cryotherapy Laser Scleral buckling Vitrectomy Pneumatic
how does Cryotherapy work at treating a RD
a cyroprobe freezes the retina - delivered via the sclera
what is an immediate affect of cryotherapy and how does this gradually change
Immediate oedema of all layers and choroidal congestion
By day seven oedema resolves and congestion absorbs, mild lesions show retraction, firm chorioretinal adhesion
retina becomes half of it’s pre tx thickness
which types of breaks is it easier to treat with cryotherapy
anterior breaks
what can cryotherapy result in
ERM
due to proliferation of RPE cells
how does laser work in repairing a retinal break
Energy absorbed by RPE (and haemoglobin)
Results in photoreceptor death and proliferation of glial tissue resulting in fibrosis/tissue adhesion
what laser temperature results in photocoagulation
10-20°C rise
what laser temperature will produce immediate and visible burns
30-70°C rise
Post-retinopexy \_\_% weaker at 8 hours \_\_% of normal strength at 18 hours \_\_\_\_% at 24 hours \_\_\_\_% at 2-4 weeks
Post-retinopexy – 50% weaker at 8 hours – 95% of normal strength at 18 hours – 140% at 24 hours – 190% at 2-4 weeks
what is the lincoff rule of a Inf RD with equal SRF
Break is at 6
what is the lincoff rule of a Inf RD with unequal SRF
Inferior break on side with higher SRF
what is the lincoff rule of a Inferior bullous RD
Superior break
what is the lincoff rule of a Extensive Inf RD
Superior break level with lowest border of SRF
what is the lincoff rule of a Subtotal RD
Superior break nearest highest border
what is the lincoff rule of a Extensive Sup RD
Superior break on side with lowest level of SRF
what 2 things does does scleral buckling dramatically reduce
vitreous traction and intraocular currents
how does scleral buckling tamponade a retinal break
Vitreous used to tamponade break internally and explant used externally to support retina
what other tx is used in conjunction with scleral buckling
Retinopexy (Laser/cryo) used in conjunction to seal retinal breaks
which tx does not increase incidence of cataract
scleral buckling
what can scleral buckling affect
refractive error; induce astigmatism and myopia
when is scleral buckling tx best utilised
when PVD not present and patients without lens opacity
how does a vitrectomy work to tx a RD
Eliminating vitreous traction
which type of px is a victrectomy primary used in for treating a RD
in pseudophakic eyes with PVD
what other surgery can a vitrectomy be combined with
cataract surgery
which 3 types of internal tamponades can a vitrectomy procedure be combined with and what is each one for
Gas (or air) for superior breaks
Heavy liquid for inferior breaks
Silicone oil for long-term tamponade
what is the redetachment rate with scleral buckling
25%
what is pneumatic retinopexy and what are the advantages of this procedure
Gas used to support retina
Can be done as outpatient procedure and does not need specialist theatre equipment or specialist surgeon
Reduced incidence of cataract formation
Quicker recovery
what are the 3 inclusions that apply to pneumatic retinopexy
A singe retinal break or group of breaks, no larger than one clock hour (30 deg) in a detached retina
All breaks in detached retina to lie above the 8 and 4 o’clock meridian
Breaks or lattice degeneration in attached retina at any location (even inferior) allowed
what is the success rate of pneumatic retinopexy vs a vitrectomy
80% vs 93% for vitrectomy
which treatment of RD has a better VA outcome and which has a higher incidence of cataract surgery for pneumatic retinopexy vs vitrectomy
pneumatic retinopexy has a better VA outcome
higher cataract surgery for vitrectomy
