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 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 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 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 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 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 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.