vitreoretinal Flashcards
what is peripheral retinal degeneration
These are abnormalities in the peripheral retina.
examples
lattice degeneration
degenerative retinoschisis
what is lattice degeneration and its characteristics
more common in
These describe areas of thinning in the neurosensory retina (NSR) with overlying vitreous liquefaction and vitreoretinal adhesions, characterized by circumferential zigzag white lines with oval holes within the lesion.
more common in myopic eyes
30% of patients with acute rhegmatogenous retinal detachment (RRD) have lattice degenerations
which degeneration predisposes you to retinal tears
lattice
prophylatic Mx of lattice degeneration what is it and when should it be offered
only be offered to those patients with a retinal detachment (RD) in the contralateral eye, in the form of laser retinopexy.
what is degenerative retinoschisis
seen usually where
microcystic degeneration resulting in the splitting of the retinal layers between the outer plexiform and inner nuclear layers, usually inferotemporally.
features of degenerative retinoschisis
● Smooth convex and immobile elevation of retina with no demarcation line of chronicity as with RRD.
● Associated with absolute field defect.
mostly bilateral adn symmetrical condition
more common in hypermetropic eyes
what is posterior viterous detachment
why does it occur
Posterior vitreous detachment (PVD) is the separation of the posterior vitreous cortex from the NSR.
occurs with increasing age ->vitreous becomes more liquefied (synchysis) -> creation of empty pockets of fluid within the vitreous, leading to vitreous collapse (syneresis). Eventually fluid escapes in the retrovitreous space separating the posterior hyaloid from the NSR
features of posterior vitreous detachment
● Photopsia (light flashes) with associated floaters. VA usually not affected.
● Weiss ring: Thickened vitreous avulsed from optic disc.
● Shafer sign (pigmented particles or ‘tobacco dust’ in the anterior vitreous)
negative.
Mx of posterior vitreous detachment
Warn about risk of RRD and advise on presenting immediately if symptoms worsen or visual field affected.
● If complicated with retinal tear, treat with laser or cryoretinopexy.
high risks of Retinal detachment
● High myopia >6D ● Aphakia ● Giant retinal tear ● Symptomatic U-shaped retinal tear ● Systemic disease (e.g. Stickler syndrome)
what is a retinal tear
ass w
features
Mx
U-shaped defect due to anterior vitreoretinal traction on a strip of retina due to PVD
associated with vitreoretinal adhesions such as at the margins of lattice degenerations.
flashes, floaters, Weiss ring and Shafer sign positive
symptomatic U-shaped retinal tears should be treated with laser retinopexy.
what is giant retinal tear
Location of tear
ass w
retinal tear extending ≥3 clock hours (≥90°).
Location: Peripheral retina at posterior border of vitreous.
Associated with PVD, as are retinal tears. trauma, high myopia, diseases (e.g. Marfan or Stickler syndrome).
Mx
laser retinopexy for both eyes.
what is retinal dialysis
mx
A disinsertion of the retina at the ora serrata involving anterior and posterior to the vitreous base. Traumatic retinal dialysis is more common and located superonasally.
Idiopathic dialysis is more commonly located inferotemporally. Retinal dialysis is the leading cause of traumatic RD in children and young adults. Management is with laser retinopexy if there is no associated RD, otherwise scleral buckle is used.
what is retinal detachment
types of retinal detachment
separation of the NSR from the RPE. -> subsequent shift of subretinal fluid (SRF), called shifting SRF, in the space between the NSR and the RPE.
Three main types of retinal detachment exist: RRD, tractional RD and exudative RD.
what is rhegmatogenous retinal detachment
most common form of retinal detachment and occurs due to a retinal break. Fluid seeps in between the NSR and RPE causing a detachment
This is an emergency – it can lead to blindness if left untreated.
features of rhegmatogenous retinal detachment
● Flashes and floater.
● Curtain-like visual field loss (relative field loss).
● dVA if macula is involved.
● RAPD, Weiss ring and Shafer sign.
● Presence of PVD and retinal breaks (commonly a U-shaped retinal tear;
most common location is superotemporal).
features of fresh RRD
● Fresh RRD
- Convex and corrugated dome-shaped surface with loss of RPE markings
- Shape based on most superior retinal break.
- Extend from ora serrata to optic disc.
- They are progressive and may affect macula.
features of chronic RRD
Retinal thinning. Demarcation lines. Intraretinal cysts.
Proliferative vitreoretinopathy.
Ix for rhegmatogenous RD
Mx
● Slit lamp biomicroscopy with wide-field lens.
● Indirect ophthalmoscopy with scleral depression to visualise the ora serrata.
● B-scan USS if there is no view of posterior pole such as dense cataract or
vitreous haemorrhage.
Mx
● Vitrectomy: Most commonly used procedure, indicated for posterior retinal breaks, giant retinal tears and proliferative vitreoretinopathy.
● Scleral buckle: Very high success rate. Used in simple RRD and retinal dialysis when there is no pre-existing PVD.
● Pneumatic retinopexy: Lower success rate but also fewer side effects; used in carefully selected cases with small superior breaks 1 clock hour apart between 11 and 1 clock hours.
what us tractional retinal detachment
retina pulled off by membranes
vitreoretinal traction. This is an insidious process where fibrovascular membranes cause progressive contracture over areas of adhesions eventually causing a detachment. The most common causes are advanced proliferative diabetic retinopathy and ROP.
- Diabetic retinopathy
- Retinopathy of prematurity • Sickle cell retinopathy
features of tractional retinal detachment
Mx
● Usually asymptomatic (no flashes or floaters), as there is no PVD.
● VA affected once macula is threatened, causing distortion of vision.
● Detachment: Shallow immobile concave tenting of retina.
● Minimal shifting SRF.
● Associated relative visual field loss, signs of underlying disease.
● Vitrectomy with membrane peel.
what is exudative retinal detachment
damage to the outer blood-retinal barrier resulting in FLUID accumulation in the subretinal space
Fluid leakage occurs under the retina thereby separating the NSR from the RPE. This occurs when the compensatory mechanisms of the RPE fail to pump the fluid back into the choroidal circulation.
• Choroidal neoplasms/metastases (melanoma)
aetiologuy of exudative retinal detachment
● Tumours: Choroidal tumours.
● Idiopathic: Nanophthalmia leading to uveal effusion syndrome.
● Vascular: Exudative age-related macular degeneration, Coats’ disease,
central serous chorioretinopathy.
● Inflammatory
Posterior uveitis: Sympathetic ophthalmia and VKH.
Posterior scleritis, orbital inflammatory disease, postop inflammation and extensive pan-retinal photocoagulation.
features of exudative retinal detachment
● Floaters if vitritis present, dVA if macula is affected.
● RD: Smooth convex that is shallow or bullous. Lack of PVD and retinal tears
and evidence of traction.
● Evidence of underlying condition.
Mx of exudative retinal detachment
● Ophthalmic and systemic history and examination including blood pressure and urinalysis.
● Treatment of underlying cause treats the retinal detachment; surgery not usually indicated.
what is vitreous haemorrhage
mechanism
leeding into the vitreous chamber. May be due to two basic mechanisms: rupture of vessels through trauma or bleeding from pathological processes.
causes of vitreous haemorrhage
● Trauma
- Blunt or penetrating trauma causing closed or open globe injury.
- Shaken baby syndrome.
- Acute PVD-associated with vitreous haemorrhage.
● Neovascularization leading to haemorrhage - Diabetic retinopathy. - Sickle cell retinopathy. - ROP. - Wet ARMD. - Retinal vein occlusion. ● Other: Choroidal tumours.
Ix for viterous haemorrhage
● All patients need a detailed fundal examination to assess the severity of haemorrhage and exclude retinal tears.
● Indirect ophthalmoscopy aids in visualization of the peripheral retina.
● B-scan USS to exclude retinal tears.
Mx for viterous haemorrhage
● Management is directed depending on the cause.
● Pan-retinal photocoagulation if there is a fundal view.
● Intravitreal anti-VEGF if there is no fundal view or in wet ARMD.
● Pars plana vitrectomy, often pre-treated with intravitreal anti-VEGF, for non-clearing vitreous haemorrhage or in presence of retinal detachment.
what is choroidal detachment
A detachment of the choroid from the sclera due to the accumulation of fluid or blood in the suprachoroidal space.
aetiology + features of choroidal detachment
● Acute hypotony (IOP <5 mmHg), typically following glaucoma surgery.
● Trauma.
● Smooth, dark and convex elevation arising from the periphery.
● Large ‘kissing’ choroidal detachments can lead to RD.
what is choroidal rupture
examination findings
break in the choroid may result from closed globe injury due to blunt trauma. There is usually disruption of the choroid, Bruch membrane and RPE; however, the neurosensory retina is unaffected.
On examination, a crescent-shaped yellow subretinal streak is seen usually adjacent to the optic disc.
what is uveal effusion syndrome
most commonly seen in who
ass w
rare and bilateral abnormality of the choroid and sclera. It is most commonly seen in middle-aged hypermetropic males and is associated with nanophthalmos (axial length <20 mm).
features of uveal effusion syndrome
Mx
● Mild inflammation ● Thickened sclera ● Ciliochoroidal detachment ● Exudative RD ● RPE hypertrophic areas (‘leopard spots’) in chronic cases
● Full-thickness sclerotomies.
what is epiretinal membrane
avascular fibrocellular sheet or membrane that develops on the surface of the retina. It is more common in female patients. These arise from proliferation of RPE, glial cells or hyalocytes on the surface of the retina. Contracture on the retina leads to problems such as elevation of the retina and CMO.
synonyms of epiretinal membrane
● In appearance: Cellophane maculopathy, macular pucker.
● In pathogenesis: Premacular fibrosis, idiopathic premacular gliosis.
causes of epiretinal membrane
● Idiopathic ● Trauma ● Posterior uveitis ● BRVO ● Iatrogenic (cryotherapy, photocoagulation, retinal detachment surgery)
features of epiretinal membrane
● Asymptomatic.
● Metamorphopsia and dVA.
● Cellophane membrane: May be transparent, best seen with red-free light
(look for glistening light reflex).
● Macular pucker: Thick contracted membrane with mild distortion of blood
vessels.
● Other findings: Macular pseudohole, CMO, retinal haemorrhages and
telangiectasia.
Ix and Mx of epiretinal membrane
● OCT.
● Observation: Is an option if the condition is stable.
● Vitrectomy.
what is atrophic retinal holes
- Often found during routine exam
* No associated symptoms
what is operculated retinal holes
- flap completely torn away, less likely to progress to detachment
- originate in focal areas of vitreoretinal abnormalities
RFs for RRD
- PVD–posteriorvitreousdetachmentare the most common cause for retinal holes and tears
- Latticedegeneration
- Highmyopes
- Undergonecataractsurgery–particularlyif this was complicated by vitreous loss
- Previous detached retina in the fellow eye
- Peripheralretinalbreaks
- Eyetrauma
what is macular hole
A full-thickness defect in the fovea with splitting of all neurosensory retinal layers from the internal limiting membrane to the RPE. This condition is a common cause of central visual loss in females aged 60–70.
primary and secondary causes of macular hole
● Primary: Vitreous traction on the fovea from a PVD (vitreomacular traction).
● Secondary: Does not have vitreomacular traction. For example, cases caused
by trauma or high myopia.
features of maculae hole
● Metamorphopsia with central dVA.
fundoscopy and slit lamp findings and name of the test
Fundoscopy:
• Tiny punched out area in the centre of the macula.
• May be yellow-white deposits at the base.
- Slit lamp: Watzke Allen Test
- Round excavation with well defined borders interrupting the slit lamp beam. The patient doesn’t see the entire beam – but sees a gap in the beam.
- Hole typically surrounded by a grey halo of detached retina.
IVTS classification of macular hole
Vitreomacular adhesion Vitreomacular traction (VMT)
Small or medium macular hole with VMT
Medium or large macular hole with VMT
Small, medium or large macular hole without VMT
Gass classification of macular hole
Stage 1: Impending macular hole
with loss of foveal depression Stage 2: Small full-thickness
macular hole (<400 microns) Stage 3: Large full-thickness
macular hole (≥400 microns) Stage 4: Full-thickness macular
hole with PVD evidenced by a Weiss ring (
Mx of macular hole
● Usually, patients are observed in stage 1.
● Stage 2 macular holes can be managed with either vitrectomy or intravitreal
vitreolysis with ocriplasmin.
● Stages 3 and 4 can be managed with vitrectomy, internal limiting membrane
peel and gas tamponade.
what is x linked retinoschisis
X-linked retinoschisis is different from degenerative retinoschisis, which is discussed under peripheral retinal degenerations. X-linked retinoschisis is due to intercellular adhesion abnormalities which lead to splitting of the retina at the nerve fibre layer.
features of x-linked retinoschisis
Ix
● Typically presents in early childhood: Hypermetropic boys present with reading difficulties at primary school.
● On examination: Bilateral maculopathy, foveal schisis with spoke-like folds with cystoid changes. Resembling CMO without leakage on FA.
Ix
● Scotopic ERG (-ve ERG): Normal a wave, loss of b wave with oscillatory potentials.
what is stickler syndrome
features
Mx
Stickler syndrome is the most common inherited cause of RD. This condition is AD and occurs due to a defect in collagen synthesis (mainly type II).
FEATURES
● Ophthalmic: High myopia, cortical cataracts, ectopia lentis, glaucoma, optically empty vitreous, radial lattice-like retinal degeneration and RRD.
● Sensorineural deafness.
● Pierre Robin features: Micrognathia, glossoptosis, cleft palate, flat nasal
bridge and maxillary hypoplasia.
● Marfanoid features.
MANAGEMENT
● Prophylactic 360° retinal laser.
● Vitrectomy if RD occurs.
what is wagner syndrome
features
This AD disorder is similar to Stickler syndrome but without the systemic features.
FEATURES
● Low myopia
● Cortical cataracts
● Optically empty vitreous
RD is linked to this condition but is less common than in Stickler syndrome and so they are treated if they occur (not prophylactically).
