Risk Factors for RVO and CRVO
1. Age
Age is the most important factor, since over 90% of cases occur in
patients over the age of 55 years.
2. Hypertension
A high blood pressure is present in up to 73% of CRVO patients over
the age of 50 years and in 25% of younger patients. Inadequate
control of hypertension may also predispose to recurrence of CRVO
in the same or fellow eye.
3. Hyperlipidaemia
RVO(Retinal Vein Occlusion)
 RVO is the most retinal vascular disease after diabetic
retinopathy.
 RVO is 3 times more common than CRVO.
 Usual age of oneset is 60-70 years.
 Approximately 16 million people
4. Diabetes mellitus
Hyperglycemia is present in about 10% of cases over the age of 50
years but is uncommon in younger patients. This may be due to an
associated higher prevalence of other cardiovascular risk factors such
as hypertension which is present in 70% of type 2 diabetics.
5. Oral contraceptive pill
In younger females the contraceptive pill is the most common
underlying association, and should not be taken following retinal
vein occlusion. The risk may be exacerbated by thrombophilia.
6. Raised intraocular pressure
A high IOP increases the risk of CRVO, particularly when the
site of obstruction is at the edge of the optic cup.
7. Smoking
Current smoking may be associated with an increased incidence
of CRVO.
sequelae of RVO & CRVO
 1.The most common is the development of cystoid macular
oedema (CMO) with a consecutive deterioration in vision.
 2.Hypoxia-induced production of VEGF (vascular endothelial
growth factor)
 Mean ± Standard Deviation Macular Thickness
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in 50 Normal Eyes Using Cirrus HD-OCT
Parameter HD-OCT StratusOCTa
Fovea (500 μm) 258.2 ± 23.5 212 ± 20
Inner ring
(1.5-mm radius)
Superior 326.6 ± 18.9 255 ± 17
Inferior 326.0 ± 24.4 260 ± 15
Temporal 312.6 ± 17.1 251 ± 13
Nasal 328.6 ± 18.3 267 ± 16
Outer ring
(3-mm radius)
Superior 282.5 ± 14.9 239 ± 16
Inferior 270.9 ± 13.9 210 ± 13
Temporal 266.3 ± 17.7 210 ± 14
Nasal 295.5 ± 17.0 246 ± 14
OCT = optical coherence tomography.
Anti_VEGF in Ophthalmology
1.Exudative AMD (Wet)
2.PDR
3.CRVO & BRVO
4.ROP
5.Iris neovascularization
Anti_VEGF in Ophthalmology
 Ranibizumab (Lucentis) and Bevacizumab (Avastin)
have become the main stay treatments for:
1.Exudative AMD,”Wet” age related macular
degeneration (AMD).
2.PDR (Proliferative diabetic retinopathy).
3.CRVO & BRVO Retinal vascular occlusion
4.ROP : Intravitreal Avastin was used for salvage
treatment in progressive treshold ROP to stabilize
eyes that had been worsening with prior laser
treatment.
 (so avastin has a definitive role and as a primary therapy for ROP.)
Anti-VEGF for BRVO & CRVO
 RVO and CRVO can lead to persistent macular edema.
 Prospective clinical trial on 29 patients with BRVO or
CRVO.
Number of Injection
 3 initial intravitreal avastin injection of 1 mg at a monthly
interval.
Retreatments
 Retreatment was based on central retinal thickness (CRT)
based on optical coherence tomography (OCT).
 If continuous injections were indicated up to month 6,the
dose was increased to 2.5 mg.
Results of the 12 months
 Visual acuity increased from 20/100 to 20/50.
 CRT decreased from 558 micrometer At baseline to 309
micrometer at month 12.
No of Injection
 Patients received a mean of 8 out of 13 possible injection.
Side-Effects
 No drug related systemic or ocular side effects were
observed.
Conclusion
 Intravitreal therapy using avastin appears to be a safe and
effective treatment in patients with macular oedema
secondary to retinal vein occlusion.
Main Limitations
 Is its short-term effectiveness and high recurrence rate.
 Retinal Vein Occlusion
 howing dilated and tortuous retinal veins, macular and disc edema, peripapillary cotton wool
spots, and scattered intraretinal hemorrhages. Superimposed on the clinical photo are the
corresponding SD-OCT line and cube images demonstrating cystoid foveal edema and
subfoveal exudative retinal detachment.
 Typical nonischemic central retinal vein occlusion in the left eye
of a 48-year-old African-American male.
 CRVO
 Retinal Vein Occlusion
Patient selection in BRVO
 According to BRVO study only patients with macular edema
associated with BRVO and a visual acuity of 20/40 or less
showed a significant visual benefit compared with the
untreated control group.
Intravitreal Trimcinolone
 For macular oedema secondary to both BRVO and CRVO but
were only able to show stabilization or a moderate
improvement in visual acuity. But has high rate side effects
such as cataract or increased IUP.
 A 73-year-old male with bilateral CRVO and CME. SD-OCT shows CME in the right eye
(top) with a VA of 20/70. After two injections of Avastin, there was less subretinal fluid
(middle) and VA was 20/60. After continued treatment, there was persistent CME and VA was
still 20/60. However, after three more injections, the CME decreased, and VA was 20/40.
 SD (spectral domain) OCT shows a relatively compact retina in the left eye (top) with a visual
acuity of 20/70, and a similar appearance after two intravitreal injections of Avastin (middle)
although a VA of 20/50. Treatment was then deferred, but one month later CME
reaccumulated and VA dropped to 20/100 (bottom). After continued treatment, the CME
decreased and VA was 20/50.
 A 70-year-old Asian male with ischemic CRVO in the right eye. Large amount of CME and
subretinal fluid is present (top). After two intravitreal Lucentis injections, retinal thickness
decreased (middle). At most recent follow up after monthly injections, SD-OCT shows less
CME (bottom) although the VA remained counting fingers the whole while.
OCT macular cross-section following 10 combination injections.
CMT 301 μm (Spectralis HD-OCT).
OCT macular cross-section following fourth combination
injection, now at two-week intervals. CMT 293 μm.
 Cross Section of Retina by OCT
 Macula is edematous from a CRVO (eye is legally blind).
 Same Patient 9 Days After Avastin Injection
 Edema has resolved (vision is 20/40).
 Long-Term Results of Intravitreal Bevacizumab in RVO
 Long-Term Results of Intravitreal Bevacizumab in RVO
 Two-Year Results of Intravitreal Bevacizumab Injection in Retinal
Vein Occlusion
 Site of injection in infants is 1.5 to 2.0 mm posterior to the
limbus that can pass through full thickness retina.
 Anterior segment of a patient with infectious endophthalmitis. Note the
global injection and steamy cornea in conjunction with the hypopyon.
Intravitreal Injection in Newborn
 Intravitreal Injection is performed on awake neonates at
bedside with a lid speculum and topical lidocaine and
betadine drops.Avastin in a dose of 0.65 is administered with
a 32-gauge needle at approximately 1.5-1.0 mm
 Posterior to the limbus.
Problems
Issue of recurrence
 Therefor follow up children treated with avastin must be
significantly extended upto 80 weeks or beyond (20 months).
Future of Anti-VEGF
 The future of anti-VEGF therapy in ROP & RVO
management looks promising, and its role must well be as an
excellent adjuant Or in lombination with laser/cryotherapy.