Retinal vein Occlusion {RVO) is a blockage of the small veins that carry blood away from the retina.. It is the 2 most common vascular disorder of the retina, next only to diabetic retinopathy.

Causes

Retinal vein occlusion is most often caused by hardening of the arteries ( atherosclerosis) and the formation of a blood clot due to following risk factors

• High blood pressure (hypertension)
• Atherosclerosis
• Diabetes
• glaucoma

Symptoms

Due to blockage there is accumulation of retinal haemorrhages and oedema leading to visual loss. It leads to sudden vision loss in all or partial loss of field of vision.

Diagnosis

DetaiIed examination includes a dilated fundus examination, shit lamp biomicroscopy besides recording be visual acuity and intraocular pressure. Following tests are commanly done as indicated

• optical Coherence Tomography (OCT) — It a non-invasive technique for obtaining cross sectional images of the rehna indicating any leakage or thickness changes in the retina. At Retina Foundation we have one of the most advanced OCT system NIDEK MIRANTE and (Heidelberg SpectrBlis) having ultra high resolution to detect any thickness chanqe at the earliest.
• Fundus fluorescein angiography (FFA) - 1t involves injection of a dye into the veins and photographing the retina to look for perfusion changes. At Retina Foundation we have one of the most advanced FFA system (Heidelberg Spectral is & Topcon)
• Blood tests - Apart from these tests you may need to get some blood tests done as recommended

Treatment

• 1) Intra vitreal injections — Intra vitreal injections may be given to treat macular oedema and also regress the leaking vessels. Along with Iaser they play a great role in stabilizing the condition of the retinopathy.

  ACCENTRIX (LUCENTIS), an Anti VEGF injection is the most commonly used approved injection for this condition and is very effective in regressing the oedema OZURDEX implant, a slow release (lonq acting) steroid is also used to reduce oedema.

  Other drugs which can be used are EYELEA and AVASTIN

  These injections are sometimes used in conjunction with Laser or Vitrectomy as well as a preparatory drug to be given a few days before surgery to reduce bleeding during surgery.

  The timing and usage would be decided and recommended by the surgeon. They usually given as a loading dose of 3 consecutJve mDnLhly injections and may need to be repeated in case of a persistence or recurrence of oedema.

• 2) Laser photocoagulation — The purpose of this treatment is to arrest the progress of the changes within the retina and help to retain existing vision. By deliberately destroying some parts of the retina, photocoagulation helps regression of abnormal new blood vessels, thereby reducing the risk of vitreous hemorrhage/tractional retinal detachment.

  Laser treatment is usually performed as an outpatient procedure. The patient is given topical anesthesia to prevent any discomfort and is then positioned before a slit lamp. The ophthalmotogist directs the laser beam precisely on the target with the aid of the slit lamp and a special contact lens. Initially 1 or 2 sittings of laser are requiied to accomplish the task. However, additional sittings may be required in the future according to the patient's condition. The type of treatment (PRP/Focal) depends on the extent and location of damaged capillaries. At Retina Foundation we use one of the most advanced Pattern Scan Laser systems for the same.

• 3) Vitrectomy — In case there is a vitreous or subhyaloid haemorrhage blocking the view or a tractional detachment, then a surgery in the foi m of Vitrectomy is indicated. Vitrectomy is a very delicate operation performed with an operating microscope and special needle-sized instruments wherein the haemorrhage is cleaned or the retina is reattached . Endo laser is carried out to regress the bleeders. In Retina Foundation this procedure can done using the state of the art Micro Incision Vitrectomy System (MIVS)

Prevention

Retinal vein occlusion is a sign of a general blood vessel (vascular) disease. The same measures used to prevent other blood vessel diseases, such as coronary artery disease, may decrease the risk of retinal vein occlusion.

These measures include:

• Eating a low-fat diet
• Getting regular exercise
• Maintaining an ideal weight
• Not smoking

Controlling co existing systemic conditions Such as diabetes and hypertension would be helpful in preventing retinal vein occlusion.