3. With the introduction of advanced neonatal
life support, survival of preterm neonates
has increased significantly.
Prematurity and low birth weight carries a
significant risk factor for ocular morbidity.
Retinopathy of prematurity (ROP) is an
emerging cause of blindness in the
developed country.
4.
5. Retinopathy of prematurity (ROP) is a bilateral
proliferative retinopathy, occurring in
premature infants with low birth weight who
often have been exposed to high concentration
of oxygen.
Well known as Retrolental fibroplasia
6. ROP, was first correlated with prematurity by
Terry in 1942.
Originally described as “Retrolental Fibroplasia”.
The term “ Retinopathy of Prematurity “ was first
suggested by Heath in 1952.
7. • Nearly disappeared between 1954-1970,
when oxygen use severely restricted.
• But now, has returned, secondary to
improved neonatal practice of LBW infants.
8. Every year, an estimated 15 million babies
are born preterm (normal gestation is 37–
42 weeks)
Approximately 20,000 of these babies will
become blind from retinopathy of
prematurity (ROP) every year
An additional 12,300 will be left with visual
impairment.
9. Countries with the highest number of
preterm births are India, China, Nigeria,
Pakistan and Indonesia.
East Asia, South East Asia, and the Pacific
are the regions with the highest number of
preterm babies who survive, and the
highest number who develop visual loss
from ROP
10. A total of 55 babies fulfilled the screening
criteria. ROP was present in 25.45% (n=14)
of the babies. Threshold disease was noted
in 5.45% (n=3) of the babies screened. Low
birth weight (p<0.01) and low gestational
age (p<0.01) was significantly associated
with the incidence of ROP.
Oxygen supplementation (p=<0.01) was an
independent risk factor.
Retinopathy of prematurity in a tertiary care hospital in eastern Nepal
S Adhikari 1, B P Badhu, N K Bhatta, R S Rajbhandari, B K Kalakheti
11. Gestational age ( < 32 weeks).
Birth weight of the baby.
(< 1500g and especially <1250g).
The amount of time in oxygen therapy.
12. Sepsis,
Multiple blood transfusions,
Multiple births
Hyaline membrane disease,
Use of Antibiotics,
Apnoea,
14. Various theories proposed are:
1. The Classical Theory
2. Gap Junction Theory
3. Current VEGF Theory
15. The nasal retina is normally fully vascularized
after 8 months of gestation, the temporal
periphery at or by 1 month after delivery.
Vascular endothelial growth factor (VEGF) is
believed to play an important role in the
vascularization process.
16. Two Process of Vascularization:
1. Vasculogenesis: formation of new vessels by
transformation of vascular precursor cells
2. Angiogenesis: budding from existing vessels
Interaction between IGF-1 and VEGF has been
studied and proposed to play a role in the
pathogenesis of ROP
17. Hyperoxia in the retina will cause retinal
vasoconstriction
If sustained will cause some degree of
vascular closure and injury to endothelial
cells of the most immature vessels.
18. It leads to subsequent hypoxia
later with growing age increase in retinal
metabolic demand will lead to upsurge of
VEGF
leading to abnormal neo vascularization
19. Nodules of proliferating endothelial cells from
residual vascular complexes adjacent to retinal
capillaries ablated during hyperoxia canalize to
form new vessels
These vessels not only grow within the retina,
but also erupt through ILM to grow on its
surface.
20.
21. A circle drawn on the posterior pole, with the
optic disc as the centre and twice the
discmacula distance as the radius, constitutes
zone I.
Any ROP in this zone is usually very severe
because of a large peripheral area of
avascular retina
22. A circle is drawn with the optic disc as the
centre and disc to nasal Oraserrata as the
radius. The area between zone I and this
boundary constitutes zone II.
23. The temporal arc of retina left beyond the
radius of zone II is zone III.
24. The condition has been divided into active ROP
and cicatricial ROP.
Clinically the evolution of the active ROP has
been divided into five stages
ROP
STAGE 1 STAGE 2 STAGE 3 STAGE 4 STAGE 5
25. It is characterised by formation of a demarcation
line dividing the vascular from the avascular
retina.
It is a thin, flat, tortuous, grey-white line running
roughly parallel with the ora serrata.
It is more prominent in the temporal periphery.
26.
27. Ridge arises in the region of the demarcation
line
Ridge is a scar tissue
It has height and width, and extends above the
plane of the retina.
Blood vessels enter the ridge and small isolated
neovascular tufts may be seen posterior to it
28.
29. It is characterised by a ridge with extraretinal
fibrovascular proliferation into the vitreous.
This stage is further subdivided into mild,
moderate and severe, depending on the
amount of fibrovascular proliferation.
The highest incidence of this stage is around
the post-conceptual age of 35 weeks
30.
31. It is a stage of subtotal retinal detachment
Sub divided into stage 4a and stage 4b
Stage 4a: It includes subtotal retinal detachment
not involving the macula.
Stage 4b: It includes subtotal retinal detachment
involving the macula
32.
33. It is marked by total retinal detachment which
is always funnel-shaped.
RD is due to exudation from poorly developed
new vessels
RD can also be due to fibro vascular traction
34.
35. It refers to presence of tortuous dilated
vessels at posterior pole with any stage of
ROP.
Shows tendency to progress rapidly to Stage
3 (or greater).
Associated with it is the engorgement and
dilatation of iris vessels, which result in
poor pharmacological dilatation of pupil.
36.
37. There is a spectrum of abnormal dilatation
and tortuosity of which Plus disease is the
severe form.
Pre-plus disease was later described as
vascular abnormalities of the posterior pole
that are insufficient for the diagnosis of plus
disease
But that demonstrate more arterial tortuosity
and more venous dilatation than normal.
38.
39. The ETROP trial classified pre threshold ROP
into:
Type 1 ROP
Zone I, any stage with plus disease.
Zone I, stage 3 without plus disease.
Zone II, stage 2 or 3 with plus disease..
40. Type 2 disease
Requires observation
Stage 1 or 2 in zone I without plus disease.
Stage 3 ROP within zone II without plus
disease.
Treatment is now recommended within 72
hours for prethreshold type I.
41. Threshold disease refers to stage 3 plus disease
involving 5 continuous or 8 discontinuous clock
hours.
This stage needs laser or cryotherapy in less
than 72 hours
42.
43. Recommended that a fundus examination be
performed on infants:
Who have a gestational age of 30 weeks or
less.
A birth weight of less than 1500g.
Birth weight of 1500-2000g with an oxygen
supplementation requirement or an unstable
course.
44. The first examination performed at 4 weeks
Or at less than 5 weeks after birth or at a
corrected gestational age of 30 to less than
31 weeks, whichever is later.
45. Follow-up examinations should be done every
1-2 weeks thereafter until retinal vessels have
grown normally into zone III
Or until the risk of developing ROP has passed
i.e.(about 44 – 46 weeks ).
46. If the normal blood vessels stop growing into
the periphery of the retina
Or if ROP begins to develop, examinations are
performed more frequently, either weekly or
twice a week.
47. A lid speculum may be necessary and scleral
depression is often required.
Proparacaine can be used to provide topical
anesthesia if desired
48. Pupillary dilatation with one drop each of
cyclopentolate 0.5%, phenylephrine 2%
Indirect Ophthalmoscopy with + 20 D
49. Important to be aware of the infant's status
during and immediately after the
examination
As the examination can be stressful and be
associated with bradycardia
52. Cryotherapy
◦ For threshold ROP (stage 3 in at least 5 clock
hours with plus disease)
◦ Freezing the sclera with cold probe.
◦ Multiple applications are done to the entire
avascular area anterior to the neovascular
ridge.
53. Treatment of the ridge itself is avoided,
since the ridge tends to bleed and cause
vitreous hemorrhage if frozen.
Procedure is painful and done under general
anesthesia.
Complications: Anesthesia problems; Eyelid
and conjunctivae edema
54.
55. Laser photocoagulation
Laser treatment for ROP is similar to cryotherapy.
The laser spot size is smaller than a spot of
cryotherapy.
Usually 600-1000 spots of laser as compared to
30-50 spots of cryotherapy needed.
56. Laser is a direct treatment of the retina and
its underlying tissue
Instead of the entire thickness of the eye
wall like in cryotherapy.
Most ophthalmologists treating ROP are
now using laser.
57.
58.
59. Scleral buckling:
For shallow retinal detachment - placing a
silicone band around the equator of the eye
to relieves the traction of the vitreous gel.
60. Vitrectomy:
For complete retinal detachment.
After the vitreous has been removed, the
scar tissue on the retina can be peeled or cut
away, allowing the retina to relax and lay
back down against the eye wall and to re-
attached.
61. The success rate ranges from 25% to 50% of
patients undergoing surgery.
The functional success rate is significantly
lower.
62. Intravitreal Injection of Bevacizumab (Avastin).
It has been used for the treatment of ROP but
not well established
Zone I disease is more likely to respond than
zone II.
Allowing retinal development to proceed
normally without the destruction integral to
laser treatment is a potential advantage.
64. Controlling pain,
Careful use of oxygen,
Preventing infection,
Improving nutrition by offering babies breast milk,
Good temperature control and
Supportive practices to keep babies comfortable
and stable, such as kangaroo care.
65. Kanski clinical ophthalmology
AAO eyewiki
Internet sources
Any Questions???
66.
67. oxygen saturation levels must be monitored and
kept at less than 95% to prevent reactive oxygen
species-related diseases, such as retinopathy of
prematurity and bronchopulmonary dysplasia. At
the same time, desaturation below 80 to 85%
must be avoided to prevent adverse
consequences, such as cerebral palsy. It is still
unclear what range of oxygen saturation is
appropriate for premature infants; however, until
the results of further studies are available, a
reasonable target for pulse oxygen saturation
(SpO2) is 90 to 93% with an intermittent review of
the correlation between SpO2 and the partial
pressure of arterial oxygen tension (PaO2).
68. The experiment consisted of two runs: one
was a verbal cognition task, with normal air
(21% oxygen) administered and the other was
with hyperoxic air (30% oxygen)
administered.
Hyper oxic …spo2 increaees
Editor's Notes
Hyaline membrane disease (HMD), also called respiratory distress syndrome (RDS), is a condition that causes babies to need extra oxygen and help breathing. HMD is one of the most common problems seen in premature babies a case of acute lung injury
Phototherapy is treatment with a special type of light (not sunlight). It's sometimes used to treat newborn jaundice by making it easier for your baby's liver to break down and remove the bilirubin from your baby's blood.
A low pH could mean respiratory problems, with the baby suffering a lack of oxygen.
Pretheshold ROP needs very close observation as it can rapidly progress to threshold, which needs prompt treatment
CELLULAR EFFECTS OF CRYOTHERAPY Effects of cryotherapy include: • Ischemia caused by vascular stasis and the destruction of small caliber blood vessels • Ice crystal formation inside cells leading to cell wall rupture • Denaturing of lipid- protein complexes • Osmotic stress • Tissue necrosis • Cellular apoptosis after freezing injury by the buildup of toxic concentrations of solutes inside cells September 09, 2015 Department of Ophthalmology, JNMC, Belagavi 6
7. September 09, 2015 Department of Ophthalmology, JNMC, Belagavi 7 As Cryotherapy freezes extracellular fluid, pure water crystals form extracellularly Thus, concentrating the remaining extracellular solutes The intracellular water is cooling below its freezing point but not forming ice crystals Known as Supercooling Cell membrane is permeable to supercooled water So the supercooled water will tend to flow out of the cell and freeze externally The net result is- • Cellular dehydration • Solute concentration intracellularly
For Ophthalmological uses the cryogens primarily used for cryotherapy are: • Freon (boiling point = −29.8 ̊C to −40.8 ̊C) • Nitrous oxide (boiling point = −88.5 ̊C) • Solid carbon dioxide (melting point = −79 ̊C) • Liquid nitrogen (boiling point = −195.6 ̊C) Boiling point of liquid nitrogen is by far the lowest, making it the most effective in cell destruction.
Intravitreal Injection of Bevacizumab (Avastin) for Treatment of Stage 3 Retinopathy of Prematurity in Zone I or Posterior Zone II
MINTZ-HITTNER, HELEN A. MD*; KUFFEL, RONALD R. JR MD†
