description about a vision threatening condition

1. Dr. K. Vasantha M.S.,F.R.C.S., Edin
Director RIO Chennai(Rtd)

2.  When you say detachment of the retina it means
separation of the inner layers of the retina from the
pigmentary epithelial layer with collection of fluid in
between
 This occurs because of the existence of a potential
space between the two layers, which is the original
primary optic vesicle.

3. Normally the retina remains attached by
 Mechanical forces like intra ocular pressure and
adhesion of photoreceptor matrix with the pigment
epithelium
 Physical forces like pumping effect of the pigment
epithelium
 Metabolic forces like choroidal extra cellular protein
causing osmotic pressure

4.  In the early stages with shallow detachment signs are
not definite. But the patient may complain of seeing
flashes of light in a particular part of visual field. This is
due to traction.
 If a patient complains of flashes and fresh shower of
floaters.
 Pigment dispersion behind the lens and in the vitreous
are seen (Schafer’s sign). If this sign is seen one must
look for tears in the periphery.

5.  Complaints about field loss either upper or lower
depending up on whether the detachment is lower or
upper.
 This loss of field is usually absolute especially in late
stages
 If the detachment progresses and involves the macula
gross loss of vision will occur.
 If the tear involves a retinal vessel also then the patient
will experience a shower of red floaters

7. Inferior detachment Signs
 See the grayish white color
of the detached retina
 edema around the macula,
 tortuous retinal vessels
 Folds in the retina
 Vessels which are darker in
color coursing over the folds
in the retina

9.  If the RD is in the superior quadrant look for the hole
near the upper edge of the detachment
 If superior half is detached hole will be in the 12 o’
clock position. If the detachment is descending more
on one side, hole will be slightly towards that side.
 Sub total inferior detachment – Hole will be near the
upper edge of the RD on the higher side
 Or at 6 o clock slightly on the side where the RD is
higher

10.  If the detachment is total the hole will usually be seen
between 10 and 2 o clock
 If the detachment is progressing fast it will be a
superior detachment. Here the macula also will be
involved early
 Inferior detachments progress slowly.

13.  The retina will be thinned out
 Cystic changes can occur
 Proliferative vitreo retinopathy will be seen
 Complicated cataract also can occur

14.  Must be done as early as possible to prevent macula
being involved
 If retina remains detached from its blood supply the
photoreceptor will become unviable
 Complications like retinal cysts and proliferative vitreo
retinopathy will occur
 Long standing RD will cause complicated cataract also
 Pigmentary line in front of detachment indicates long
duration

15.  Basically all holes and tears must closed so that further
leakage of fluid will not occur behind the neuro retinal
layers
 This is achieved by using cryo, laser or diathermy and
causing chorio retinal adhesion
 The retina is flattened and brought closer to the hole or
tear with the help of gases, implants, explants or silicon
oil
 In many cases drainage of sub retinal fluid also will be
needed to achieve this

16.  May reveal hidden breaks
 Scar will produce chorio retinal adhesion
 Can be used for anterior breaks and the space between
the break and the ora serrata. If this is not done the tear
may extend
 Can be applied trans conjunctivally
 Can be used even in the presence of vitreous
hemorrhage

17. Complications:
 Break down of blood ocular barrier
 If applied on the base release of RPE. These two will
cause PVR
 More inflammatory reactions compared to laser
 The above three will lead on to proliferative vitreo
retinopathy
 Cystoid macular edema, choroidal detachment and
exudative retinal detachment can occur

18.  Must be applied only after lamellar dissection. Otherwise
scleral wrinkling will occur, and lead on to increase in
IOP
 Sclera may perforate
 3 and 9 o clock areas must be avoided as one might
injure long ciliary nerves and arteries
 Laser: less inflammation, no damage to RPE

19.  Circumferential buckles are used for dialyses, wide
retinal breaks, multiple breaks and if breaks are at
varying distances from the ora
 Radial buckles are used when high buckles are needed
as in large flap tears which may gape with circular buckle
and for large posterior tears
 Disadvantage: uneven indentation and increased
chances for infection, extrusion and erosion

20.  Symmetric tyres
 Asymmetric tyres: provide increased buckle height
posteriorly, decrease the likelihood of erosions anteriorly
and help to placement of encircling band in the
equatorial region
 Bands
 Strips
 Wedges

21.  Less incidences of infection
 Diathermy can be used
 SRF drainage can be done in place where diathermy
has been done
 Disadvantage: scleral dissection is mandatory,
increased IOP due to shrinkage and chances of
intrusion

22. Drainage of sub retinal fluid is needed
 to localize holes which are not seen
 To provide intra operative contact between break and
buckle
 To verify buckle position esp. in multiple holes
 To reduce intra ocular volume for injecting air or gas
for tamponade
 If defective reabsorption is suspected

23.  High detachments
 Lower quadrant viscous fluid
 Aphakia and myopia as syneritic vitreous cannot block
the rent
 PVR, giant tears and multiple breaks
 Glaucoma to keep the tension low
 Old people as the RPE may not be able to pump out the
SRF

24.  Site: preferably just above or below the horizontal meridian as
the choroid is less vascular here
 Nasal quadrant is preferred as in case of bleeding it will not
reach the macula
 Cryoed areas must be avoided as choroidal congestion will lead
on to hemorrhage
 Beneath the buckle – if retinal incarceration occurs support will
be there
 If fixed folds are there choose that area as incarceration will not
occur

25.  Incision: radial, about 3 – 4 mm
 Diathermy: is applied to enlarge the wound and close the
vessels in that area
 Usually the scleral fibers will swell and close the wound
 Complications: fish mouthing, glaucoma, anterior
segment ischemia, cilio choroidal detachment,
proliferative vitreo retinopathy, infection, migration of
implants and epiretinal membrane

26. Used when there are
 Multiple breaks
 Aphakia or pseudophakia
 High myopia
 Extensive lattice
 vitreo retinal degenerations

27.  Proliferative vitreo retinopathy (PVR) grade 1
 Trauma
 If there are no recognizable breaks or tears
 Giant retinal tears
 Disadvantage: 360 degrees peritomy, myopic shift and
danger of anterior segment ischemia in sickle cell
anemia

28.  Air: was used by Ohm in 1911.
 Easily available, free of cost, doesn’t expand
 No need for removal
 But stays only for a few days

29.  Sulfur hexafluoride (SF6) and perfluoropropane (C3F8)
 Five times heavier than air
 Colorless, odorless and non toxic
 Can be used for pneumatic retinopexy and post
operative endotamponade
 High surface tension and diffusion of other gases from
the blood stream which expands them helps these gases
to maintain the tamponade effect
 Since they get absorbed there is no need for removal

30.  Large bubble of air can be used to treat breaks smaller
than one clock hour
 SF6 expands 2.5 times in 36 hrs, maintains a bubble for 7
– 10 days and gets absorbed in 10 – 14 days
 C3F8 will become 4 times in size in 72 hrs and will
effective for 4 – 6 weeks. The gas will absorbed in 6 – 8
weeks. In aphakic and vitrectomized eyes it will be
absorbed faster

31.  Gases are used mainly for superior tears and holes as it
will raise up when the patient is erect
 Inferior retinal attachment can be achieved but the
patient has to maintain a face down position for
prolonged periods which is not feasible

32.  Contra indications: immediate air travel, nitrous oxide
anesthesia
 Complications: inadequate bubble size, migration, visual
field defects in long standing bubbles due to drying.
 Lens feathering: if the gas was in contact with the back
of the lens due to improper positioning, posterior sub
capsular opacity will form.

33.  If the gas comes in contact with endothelium in aphakia
– damage to endothelium will occur
 In scuba divers when they go down the gas will shrink
causing hypotony. When they raise up the bubble will
enlarge in size causing increase in IOP

34.  Clear inert hydrophobic polymer
 Refractive index 1.4035
 Density 0.975. So it is lighter than water- can be used
for superior tears
 Inter facial tension of air to water is 70dyne/cm3, but
with silicon oil is it is only 40.
 So air is used to flatten the detachment and then
silicon oil is injected

35.  Suspected or lost retinal breaks
 Pre retinal hemorrhage
 Posterior breaks if not treated with photo coagulation
or cryo
 Persistent tangential traction with breaks
 Multiple breaks
 Highly adherent or contracted ERM that requires retinal
resection to relieve traction

36.  When prolonged tamponade is needed – PVR or likely
develop one
 Post op positioning not feasible
 Vitreous hemorrhage after vitrectomy done for
proliferative diabetic retinopathy or membrane
removal. The blood will not mix with oil. So clotting
factors will be concentrated and compartmentalized.
But if it is over the macula tissue plasminogen
activator must be used.

37.  One eyed patients where immediate visual recovery
without positioning is needed.
 Cases with vitritis like herpes, HIV infection
 Progressive retinal necrosis
 When multiple retinotomies are needed
 Can be used for drug delivery

38.  Two types of silicon oil with 1000 cs and 5000 cs are
available. It is easier to inject and remove the less
viscous liquid but the incidence of emulsification is
more with that.
 After vitrectomy air is injected to flatten the retina
which is then replaced with silicon oil
 Laser can be used in the presence of oil to close the
holes and tears which is an advantage

39.  Injecting more than what is needed
 Injecting in to the sub retinal space- this is avoided by
clearing all tractions, draining the SRF, and performing
air fluid exchange. Retinotomy has to be done to
remove the oil.
 Refractive changes- negative lens effect in phakics, so
they become hyperops. Aphakic eyes will have a
myopic shift as the oil globule will act as a convex
lens. This is an advantage in aphakia

40.  Has to be removed, so second surgery is needed
 If silicon lenses are present the oil will coat the lens
and the lens will become obscure
 Bullous keratopathy
 Band keratopathy
 Increase in IOP due to pupillary block or emulsified oil
blocking the trabecular meshwork. Inferior iridectomy
is performed to avoid this. This occurs after one or two
weeks. More if TGF beta has been used.

41.  Cataract
 Emulsification – fibrin and serum are responsible.
Lower the viscosity more the chances for this
 Late complications: all of the above, endophthalmitis,
membrane formation and recurrent detachment
 Prolonged face down position can produce cervical
disc problems, ulnar nerve palsy, deep vein thrombosis
and pulmonary embolism

42.  These liquids were initially used for preserving organs
for transplant and imaging.
 These are fluorinated synthetic liquids containing
carbon and fluorine bonds
 Specific gravity is 1.76 to 2. So denser than water.
 It is optically clear and inert
 Viscosity is low can be injected and aspirated easily
with small gauge instruments

43.  It is immiscible with water. So it can be easily
distinguished from the irrigating solutions.
 Refractive index is close to water. So there is no
change in refraction and conventional contact lenses
can be used throughout.
 Photocoagulation can be performed through the liquid.
 Due to high surface tension does not pass through the
tears or holes
 Gives a better tamponade than silicon oil

44.  Toxic to retina and hence cannot be left in the
eye for long time
 Can cause inflammatory reactions

45. Indications
 Giant retinal tears- if retina does not flatten with PFCL it
means that retinal traction is still there
 Proliferative vitreo retinopathy
 Dislocated lens, fragments of lens or IOL
 Trauma with vitreous hemorrhage, sub retinal hemorrhage,
RD, intra ocular foreign body, retinal incarceration
 Supra choroidal hemorrhage
 RD with choroidal coloboma
 Detachment with macular hole

46.  Heavier than water
 Specific gravity is 1.35 g/ml hence retinal damage is
less compared to PFCL
 Refractive index is 1.3. So compatible with other
refracting tissues in the eye.
 Soluble in perflurocarbon liquids and silicon oil

47.  The higher surface tension (49.1 compared to 36mN/l
of silicon oil) helps in closing larger retinal breaks
 It can be used along with silicon oil as it is soluble
 Disadvantage is cataract formation
 Emulsification
 Epiretinal membranes

48.  Even with attached retina patient may not regain vision if
operated late as the photoreceptors would have died. This is
because the outer layers receive blood supply from the choroid,
and the detached retina remains away from the blood supply
 Failure of retina to reattach – SRF not getting absorbed, breaks
not closed properly, new breaks or missed breaks
 Endophthalmitis, proliferative vitreo retinopathy

49.  Senile retino schisis- split is between the inner nuclear
and outer plexiform layer
 Common in the lower temporal quadrant
 Progress very slowly
 Creates absolute field defect
 Has a transparent and immobile inner layer

50. Exudative detachment
 This does not have a corrugated appearance
 Surface is smooth
 No retinal breaks
 Retina will not be mobile
 The sub retinal fluid will shift and occupy the most
dependant position
 Signs of underlying cause like uveitis, tumor etc

51. Choroidal detachment
 Will be dark in color
 Anteriorly will extend beyond the Ora
 Eye will be soft
 Will not reach the disc

52. Tractional retinal detachment
 This will have a concave surface
 There will be only minimal sub retinal fluid
 Does not extend to the Ora
 The highest point will be where there is a tractional
element and it will some what acute. (unlike the smooth
elevation seen in rhegmatogenous detachment)

53.  Retina will be immobile as there is no shifting of fluid
 Signs of the causative disease like diabetic retinopathy,
retinopathy of prematurity, history of trauma will be
present
 Rhegmatogenous detachment can be seen along with
traction RD if breaks occur