NEOVASCULAR GLAUCOMA

DR SIVATEJA CHALLA

Definition History Etiology Pathophysiology Clinical course Clinical features DD’S Investigations Treatment

DEFINITIONSevere form of secondary glaucoma characterised by fibro vascular

proliferation in the anterior chamber angle.

SYNONYMS1. Hemorrhagic glaucoma2. Thrombotic glaucoma3. Rubeotic glaucoma4. Congestive glaucoma

HISTORY 1906 Coats , NVI in CRVO termed as RUBEOSIS IRIDIS

1937 Kurtz , NVA leading to PAS formation

1963 Weiss et al, coined the term NEOVASCULAR GLAUCOMA

ETIOLOGYDiabetic retinopathy (M.C.C)

CRVO

Ocular ischemic disease

PATHOPHYSIOLOGYCHRONIC RETINAL ISCHAEMIA

ANGIOGENIC FACTORS RELEASED & DIFFUSED

NEOVASCULARISATION OF IRIS AND ANGLE

NEOVASCULAR GLAUCOMA

lens and vitreous acts as mechanical barriers and also releases vaso inhibitory

factors

So any complicated cat sx PCR,APHAKIA more predisposition

VEGF synthesised by all tissues in retina, mainly MULLERS CELL.

VEGF conc 50-100 times more in aqueous humour in NVG

STAGES PRE RUBEOSIS

PRE GLAUCOMA (RUBEOSIS IRIDIS )

OPEN ANGLE GLAUCOMA

ANGLE CLOSURE GLAUCOMA

Pre rubeosis stage1. In patients with predisposing risk factors such as DR, CRVO, etc it is important

to understand the risk of developing rubeosis irides and the chances for

progression to NVG.

2. Look carefully for NVI and NVA under high ,magnification

Pre glaucoma stage : rubeosis iridisa. NVI +/- NVA

b. IOP normal

c. Patients are asymptomatic

d. dilated tufts of preexisting capillaries and fine, randomly oriented vessels on the surface of the iris near the pupillary margin

Open angle glaucoma1. Elevated IOP

2. NVA and NVI increased

3. AC inflammatory reaction

4. Hyphema may be present

5. No PAS

6. Angles open

Fibro vascular fibrovascular membrane that covers the angle and anterior surface of the iris and may even extend onto the posterior iris

HALLMARK

Angle closure glaucoma Most patients are detected in this stage

PAS formation

Fibro vascular membrane contarcts leads to flat iris

Ectropion uveae present

IOP very high >60 mm hg

CLINICAL FEATURESSYMPTOMS

- Severe pain

- Headache ,vomiting

- Redness

- Watering

- Defective vision

- Photophobia

SIGNS- Reduced vision

- Ciliary injection

- Corneal oedema

- Deep AC with flare

- Hyphema

- Fixed dilated pupil

- NVI, NVA

- Raised IOP

Features Normal vessels New vessels

Location Iris stroma Pupillary marginsAngles

Arrangement Regular Irregualr

Appearance Tortuous Thin

Course Radial Arbourising

Character Not fenestrated Fenestrated

Scleral spur Not cross Crosses

Flouroscein No leakage leakage

DIFFERENTIAL DIAGONOSIS1. PACG no NVI and NVA

2. UVEITIC GLAUCOMA KP’S + ,Complicated cataract, band shaped keratopathy

3. FHI stellate KP’S, NVA+ ,NVI and NVG are rare

4. ICE syndrome corneal decompensation,correctopia,iris atrophy

5. Old trauma angle recession,iris pigment clumps, no NVI

6. Lens induced glaucoma

INVESTIGATIONS OCULAR : - Fundus Fluorescein Angiogram- to assess retinal ischaemia -Electroretinogram – to assess for retinal ischemia -Iris angiography- in cases of doubtful NVI, to confirm the diagnosis

-B scan ultrasound- if view of retina not SYSTEMIC : - BP, FBS PPBS, Carotid Doppler, lipid profile,renal profile

TREATMENTA. Identifying the underlying etiology and its timely and adequate treatment to

prevent the development and progression of NVG.

B. Once NVG develops and IOP is high, the major aspect of management is

control of high IOP to prevent optic nerve damage and continuous treatment

of underlying etiology.

Prophylactic treatment Pan retinal photocoagulation (PRP) DM In established cases of PDR, PRP +/- IVB done to prevent NVG

And even after PRP, close f/u is needed

CRVO PRP indicated only after 2 clock hours of NVA/NVI (CVOS)

OIS PRP indicated for cases with retinal ischemia on FFA

refer for neurological and cardiology assessment

Pan retinal photocoagulation

Make ischemic retina anoxic

Decreased angiognic factorDecreased new vessels

Reduces AS neo vascularisation

Goniophotocoagulationa. Adjunct to PRP

b. LASER therapy aimed at directly treating the NVA before development of NVG

c. No role once glaucoma is established

d. Low-energy argon laser treatments (0.2 seconds, 50-100 um, 100 - 200 mW) are applied to the neovascular tufts as they cross the scleral spur.

Management of glaucoma Medical management

Aqueous suppressants- beta blockers, carbonic anhydrase inhibitors, alpha agonists

Topical prostaglandin analogues can be tried though they may increase ocular inflammation

Miotics are contraindicated as they can increase inflammation and discomfort.

Frequent administration of are recommended to reduce inflammation that is inevitably

present topical steroids and cycloplegics .

Anti angiogenic drugs like bevacizumab intravitreal or intra cameral, reduces angiogenesis and

reduces inflammation

Management of glaucoma Surgical management :

1. Medical management with intra vitreal anti-VEGF along with retinal ablation

wherever possible may be sufficient to control the IOP in the open angle

stage of NVG

2. But in advanced stage with synechial angle closure surgical intervention for

IOP lowering is often required.

Surgical management Trabeculectomy Tube shunts Cycloablation

Trabeculectomy :a. Intraoperative use of anti-fibrotic agents is recommended to reduce the risk

of bleb failure due to subconjunctival scarring

b. The success rate of trabeculectomy with MMC in NVG at 1 year has been reported to be around 62.6% and reduced to 51.7% at 5 years *

c. With the use of preoperative Bevacizumab, success rate may improve up to 95%**

* Takihara Y, Inatani M, Fukushima M, Iwao K, Iwao M, Tanihara H. Trabeculectomy with mitomycin C for neovascular glaucoma: prognostic factors for surgical failure.Am J Ophthalmol 2009; 147:912–8.** Saito Y, Higashide T, Takeda H, Ohkubo S, Sugiyama K.Beneficial effects of preoperative intravitreal bevacizumab on trabeculectomy outcomes in neovascular glaucoma. Acta Ophthalmol 2010; 88:96–102.

Tube shunts

I. Glaucoma drainage devices are increasingly being considered as a primary

surgical procedure especially NVG where there is a high risk for failure of

conventional filtering surgery

II. Scarred conjunctiva, active inflammation, vigorous new vessel growth and

prior failure of trabeculectomy are also all indications to consider tube shunt

surgery in NVG.

Cycloablation : For refractive NVG, no PL eye to relieve pain,

◦ Cyclocryotherapy.◦ TSCPC, other contact and non contact trans scleral cyclo destructive procedures.◦ Endoscopic cyclo photocoagulation.

12-24 burn spots ,posterior to limbus over 360 degrees , 1500-2000 MW, 1.5-2 secs.

Treatment

NVG

Seeing eye NLP- Medical Rx - Cyclodestructive procedure

Clear media PRP

Poor media Cryoablation

Vitreous hge Vitrectomy+ endolaser

Trabeculectomy & Mitomycin

Tube shunts cyclophotocoagulation

Conclusionsa. NVG is a potentially blinding disease

b. Early diagnosis and aggressive control of high IOP and the underlying etiology is crucial to minimize the visual loss

c. Once IOP becomes elevated, successful management of disease becomes extremely difficult

d. No current medical or surgical treatment has a high success rate.

THANK YOU