retinal detachment by Dr. Nirav MODI

1. -DR. NIRAV MODI

2. DEFINITION
 A Retinal Detachment (RD) describes the
separation of the neurosensory retina (NSR) from
the retinal pigment epithelium (RPE).
 This results in the accumulation of sub-retinal fluid
(SRF) in the potential space between the NSR and
RPE.

3. TYPES
 There are three types of retinal detachment:
1) Rhegmatogenous
2) Tractional
3) Exudative

4. RHEGMATOGENOUS
RETINAL DETACHMENT
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5.  Rhegmatogenous retinal detachment occurs due to a
break in the retina (called a retinal tear)
 Retinal breaks are the predisposing lesions than can go
into RRD.
 These retinal breaks can be of 3 types
 Retinal Tear.
 Retinal Hole,
 Retinal Dialyses,

6. PATHOGENESIS
 Presence of retinal break in concert with Vitreo-retinal
traction allows accumulation of liquefied vitreous under
the Neuro-Sensory retina, separating it from RPE.
 Even though Retinal break is present, at least partially
liquefied vitreous and/or traction must be there.
 Vitreous degeneration, PVD, Lattice degeneration,
Snail-track degeneration, WWP, high myopic eyes &
vitreous loss during cataract or YAG capsulotomy are
predisposing.

7. Symptoms
 1) Photopsia is the subjective sensation of a flash of
light. In eyes with acute PVD it is probably caused by
traction at sites of vitreoretinal adhesion.
 The cessation of photopsia is the result of either
separation of the adhesion or complete tearing away of a
piece of retina (operculum).
 Patient will often describe it as an arc of golden or white
light induced by eye movements and is more noticeable
in dim illumination.

8.  2) Floaters are moving vitreous opacities which are perceived
when they cast shadows on the retina. Vitreous opacities in
eyes with acute PVD are of the following three types:
 Weiss ring is a solitary floater consisting of the detached
annular attachment of vitreous to the margin of the optic
disc.
 Vitreous Hemorrhage secondary to tearing of a peripheral
retinal blood vessel is indicated by sudden shower of
minute red-coloured or dark spots. Usually Vitreous
haemorrhage here is usually sparse due to the small calibre
of peripheral retinal vessels.

9.  3) Visual field defect is perceived as a ‘black curtain’. In
some patients it may not be present on waking in the morning,
due to spontaneous absorption of SRF while lying inactive
overnight, only to reappear later in the day.
 A lower field defect is usually appreciated more quickly by
the patient than an upper field defect.
 The quadrant of the visual field in which the field defect first
appears is useful in predicting the location of the primary
retinal break, which will be in the opposite quadrant.

10. LINCOFF’S RULES
 A shallow inferior RD in which the SRF is slightly higher on the
temporal side points to a primary break located inferiorly on that
side
 A primary break located at 6 o’clock will cause an inferior RD with
equal fluid levels
 In a bullous inferior RD the primary break usually lies above the
horizontal meridian
 If the primary break is located in the upper nasal quadrant the SRF
will revolve around the optic disc and then rise on the temporal side
until it is level with the primary break
 A subtotal RD with a superior wedge of attached retina points to a
primary break located in the periphery nearest its highest border
 When the SRF crosses the vertical midline above, the primary break
is near to 12 o’clock, the lower edge of the RD corresponding to the
side of the break

12. SIGNS
 1) Marcus Gunn pupil (relative afferent pupillary defect) is
present in an eye with an extensive RD irrespective of the
type.
 2) Intraocular pressure is usually lower by about 5 mmHg
compared with the normal eye. If the intraocular pressure is
extremely low, an associated choroidal detachment may be
present.
 3) Iritis is very common but usually mild.
 4) Tobacco dust consisting of pigment cells is seen in the
anterior vitreous.

13.  5) Retinal breaks are usually red because of the colour
contrast between the sensory retina and underlying choroid.
However, in eyes with hypo-pigmented choroid (as in high
myopia), the colour contrast is decreased and small breaks
may be missed.

14. FRESH RETINAL DETACHMENT
 1) The RD has a convex configuration and a slightly opaque
and corrugated appearance as a result of retinal oedema.
 There is loss of the underlying choroidal pattern and retinal
blood vessels appear darker than in flat retina.
 2) SRF extends up to the ora serrata, except in the rare cases
caused by a macular hole in which the SRF is initially
confined to the posterior pole. Because of the thinness of the
retina at the fovea, a pseudohole is frequently seen if the
posterior pole is detached. This should not be mistaken for a
true macular hole, which may give rise to RD in highly
myopic eyes or following blunt ocular trauma.
 3 B-scan ultrasonography shows good mobility of the retina
and vitreous.

15. (A)U-tear
(B) Superior
bullous RD
(C) Shallow
temporal RD
(D) B-scan-
totally detached
retina with
open funnel

16. LONG-STANDING RETINAL DETACHMENT
 1) Retinal thinning secondary to atrophy is a characteristic
finding which must not be mistaken for retinoschisis.
 2) Secondary intra-retinal cysts may develop if the RD has
been present for about 1 year; these tend to disappear after
retinal reattachment.
 3) Subretinal demarcation lines ‘‘high water marks’’ caused
by proliferation of RPE cells at the junction of flat and
detached retina are common and take about 3 months to
develop. They are initially pigmented but tend to lose this
with time. Demarcation lines are convex with respect to the
ora serrata and, although they represent sites of increased
adhesion, they do not invariably limit spread of SRF.

17. Long-standing RD
(A) Secondary retinal cyst.
(B) B-scan shows a retinal cyst
(C) ‘high water mark’ in an eye
with an inferior RD

18. PROLIFERATIVE VITREO-RETINOPATHY
 Proliferative vitreoretinopathy (PVR) is caused by epiretinal
and subretinal membrane formation. Cell-mediated
contraction of these membranes causes tangential retinal
traction and fixed retinal folds.
 Usually, PVR occurs following surgery for rhegmatogenous
RD or penetrating injury. However, it may also occur in eyes
with rhegmatogenous RD that have not had previous
vitreoretinal surgery.
 The main features are retinal folds and rigidity so that retinal
mobility induced by eye movements or scleral indentation is
decreased.

19. ADVANCED PVR WITH FUNNEL LIKE RD

20. EXUDATIVE
RETINAL DETACHMENT
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21.  Exudative, Serous or Secondary
 Occurs due to inflammation, injury or vascular
abnormalities.
 Fluid accumulating underneath the retina
without the presence of a hole, tear, or break.
 Rare

22. PATHOGENESIS
 Exudative RD occurs in a variety of vascular, inflammatory
and neoplastic diseases involving the NSR, RPE and choroid
in which fluid leaks outside the vessels and accumulates under
the retina.
 As long as the RPE is able to compensate by pumping the
leaking fluid into the choroidal circulation, no fluid
accumulates in the sub-retinal space and RD does not occur.
 But if the normal RPE pump is overwhelmed or if the RPE
activity is decreased, then fluid starts to accumulate in the
sub-retinal space

23.  The main causes are the following:
1) Choroidal tumours such as melanomas, haemangiomas and
metastases; it is therefore very important to consider that
exudative RD is caused by an intraocular tumour until proved
otherwise.
2) Inflammation such as Harada disease (Part of VKH syndrome)
and posterior scleritis.
3) Bullous central serous chorioretinopathy is a rare cause.
4) Iatrogenic causes include retinal detachment surgery and
panretinal photocoagulation.
5) Subretinal neovascularization which may leak and give rise to
extensive subretinal accumulation of fluid at the posterior pole.
6) Hypertensive choroidopathy, as may occur in toxaemia of
pregnancy, is a very rare cause.
7) Idiopathic such as the uveal effusion syndrome.

24. Symptoms:
 Photopsia is absent because there is no vitreoretinal traction,
although floaters may be present if there is associated vitritis.
 The visual field defect may develop suddenly and progress
rapidly.
 Depending on the cause both eyes may be involved
simultaneously (e.g. Harada disease).

25. Signs :
 The RD has a convex configuration, just like a
rhegmatogenous RD, but its surface is smooth and not
corrugated.
 The detached retina is very mobile and exhibits the
phenomenon of ‘shifting fluid’ in which SRF responds to the
force of gravity and detaches the area of retina under which it
accumulates.
 For example, in the upright position the SRF collects under
the inferior retina, but on assuming the supine position for
several minutes, the inferior retina flattens and the SRF shifts
posteriorly detaching the superior retina.

26.  The cause of the RD, such as a choroidal tumour, may be
apparent when the fundus is examined, or the patient may
have an associated systemic disease responsible for the RD
(e.g. Harada disease, toxaemia of pregnancy).
 ‘Leopard spots’ consisting of scattered areas of sub-retinal
pigment clumping may be seen after the detachment has
flattened.

27. Exudative RD showing shifting fluid.
(A)Inferior collection of sub-retinal
fluid with the patient sitting;
(B) the subretinal fluid shifts upwards
when the patient assumes the supine.

28. Exudative RD caused by Choroidal melanoma

29. TRACTIONAL
RETINAL DETACHMENT
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30.  Tractional retinal detachment
occurs when fibrous or fibro-vascular tissue,
pulls the sensory retina from the retinal pigment
epithelium.

31. Main causes of tractional RD are
(a) proliferative retinopathy such as diabetic
and retinopathy of prematurity,
(b) penetrating posterior segment trauma

32. PATHOGENESIS
 1) Tractional RD is caused by progressive contraction of
fibrovascular membranes over large areas of vitreoretinal
adhesion.
 It is thought to be caused by leakage of plasma constituents
into the vitreous gel from a fibrovascular network adherent to
the posterior vitreous surface.
 Owing to the strong adhesions of the cortical vitreous to areas
of fibrovascular proliferation, PVD is usually incomplete.
 In the very rare event of a subsequent complete PVD,the new
blood vessels are avulsed and RD does not develop

33.  2) Static vitreo-retinal traction of the following three types
is recognized.
 A) Tangential traction is caused by the contraction of
epiretinal fibrovascular membranes with puckering of the
retina and distortion of retinal blood vessels.
 B) Anteroposterior traction is caused by the contraction of
fibrovascular membranes extending from the retina
posteriorly, usually in association with the major arcades,
to the vitreous base anteriorly.
 C) Bridging (trampoline) traction is the result of
contraction of fibrovascular membranes which stretch from
one part of the posterior retina to another or between the
vascular arcades, tending to pull the two involved points
together.

34. Tractional RD associated with Antero-posterior and bridging traction

35. Symptoms: Photopsia and floaters are usually absent because
vitreoretinal traction develops insidiously and is not associated
with acute PVD. The visual field defect usually progresses
slowly and may become stationary for months or even years.

36. Signs :
o The RD has a concave configuration and breaks are absent.
o Retinal mobility is severely reduced and shifting fluid is
absent.
o The SRF is shallower than in a rhegmatogenous RD and
seldom extends to the ora serrata.
o The highest elevation of the retina occurs at sites of
vitreoretinal traction.
o If a tractional RD develops a break it assumes the
characteristics of a rhegmatogenous RD and progresses more
quickly (combined tractional-rhegmatogenous RD).

37. (A) Tractional RD in severe
proliferative diabetic retinopathy
(B) B-scan- Incomplete posterior
vitreous detachment and a
shallow tractional RD

38.  B-scan ultrasonography shows incomplete posterior vitreous
detachment and a relatively immobile retina.