Retina is the most crucial portion of our eye as the image of any object which we want to see is formed on retina first and then signals are transmitted to brain via optic nerve. The brain then processes these signals so that we are able to see that object. If retina is damaged we cannot see objects.
For the purpose of functioning retina can be divided into two regions. The central most part is called Macula which is the most sensitive portion & is responsible for fine (sharp) visual works like reading, sewing, recognizing fine details & colors. The peripheral (outer) portion of retina helps us to see in dim light & to see things lying on our sides or periphery.
Retinal diseases / ailments can involve macula or peripheral retina or both. Diseases of macula leads to marked diminision of vision whereas diseases of periphery lead to loss of field of view & night blindness.
Retina is not directly visible by torch light examination & needs special gadgets/equipment’s to visualize it, hence diagnostic imaging of retina plays very crucial role in accurate diagnosis & treatment of retinal diseases.
At AcuraVision Clinics we have State of Art equipment’s for retinal diagnosis and treatment.
FFA (Fundus Fluorescein Angiography)
In this procedure digital photographs of retina are taken after injecting a dye named sodium fluorescein. This shows status of blood circulation in retina, any area of non- circulation, any abnormal vessel. It is also done to see effect of treatment (like- Retinal Laser) on the lesion / disease.
OCT (Optical Coherence Tomography)
It is a non- contact & non- invasive imaging modality which gives accurate and very high resolution analysis of retinal structure of macular region. It is necessary to evaluate type & extent of macular involvement and also the effect of treatment. AcuraVision Clinics have the most advanced high resolution OCT Angio installed at its Centre. Advantage of OCT Angio over OCT is that it can also give information about the blood circulation of macular region along with other information given by OCT.
MEDICAL TREATMENT OF RETINAL DISEASES
Apart from medicines, medical treatment of retinal diseases involve following very important therapies:
Retinal Laser- It is mainstay of treatment in cases of abnormal retinal vessel growth such as in diabetes, vascular occlusion, inflammation etc. Also required to treat certain vascular malformations, tumors, retinal tears & degenerations.
Intravitreal Injection-Many retinal diseases are associated with swelling of macula which can be more effectively treated by injecting certain drugs into vitreous jelly. Some such drugs are – Bevacizumab, Ranibizumab, Aflibercept, Brolucizumab etc. These drugs are collectively called ANTI VEGF drugs. VEG F (Vascular Endothelial Growth Factor) is a chemical found inside the eye.
Abnormality high levels of VEGF which has been found in many retinopathies like- Diabetic or Abnormally high level of VEGF which has been found in many retinopathies like diabetic or in vascular occlusion and retinal diseases like Wet ARMD promotes growth of abnormal new vessels and also increases leakage of fluid from them in retina. Anit VEGF drugs neutralize this chemical & thus help in slowly down growth of abnormal new vessels & leakage from them.
Depending upon the severity and type of disease, multiple injections of these drugs are often required.
Intravitreal injection of antibiotic drugs are sometime required in infections of retina & vitreous. Intravitreal steroids (Triamcinolone Acetonide, Ozurdex) are given in certain diseases / conditions with inflammations
Many retinal diseases require surgical management. Most common among this are:
Vitrectomy / Vitreo Retinal Surgery
In this a small piece of medical grade solid silicon is sewn on to the sclera (outer most wall of eye). It is usually done in cases of fresh Retinal Detachment as a standalone procedure or along with Vitrectomy in many complicated conditions. This silicon pushes sclera in (buckle) towards retinal break thus apposing them. Cryotherapy is done before it which helps break to close. Sometimes gas bubble is also needed to be placed inside vitreous cavity to push retinal break by toward buckled sclera. 90-95% of fresh uncomplicated retinal detachment can be re attached by this.
Vitrectomy / Vitreo Retinal Surgery
Removal of vitreous jelly from inside the eye is called Vitrectomy. Often along with Vitrectomy patient needs other procedures to be done on retina or scleral buckling, then it is called Vitreo retinal Surgery. In many VR surgeries filling up of vitreous cavity with silicon oil or gas is needed. Most often retina also needs to be lasered with the help of special fiber optic probe.
Conditions / Diseases requiring Vitrectomy / VR Surgery are:
Loss of vitreous transparency: In this situation light rays cannot reach retina so no image is formed thus we can’t see. Vitreous become opaque in following conditions
Bleeding in vitreous—- can occurs from
Abnormal new vessels formed in retina in many diseases like diabetic retinopathy or in vascular occlusions etc.
Wet age related macular degeneration (ARMD).
Severe inflammation or infection inside vitreous —-can occur
Following penetrating injury especially if any foreign body is retained inside eye.
Following worm cyst in vitreous
Following infection spread form other part of the body.
Separation of retina away from middle layer of eye ball is called retinal detachment. Majority of fresh retinal detachment can be managed by Cryotherapy along with scleral buckling & drainage of fluid, but 5-10% of detached retina is unable to re-attach by buckling only. Such eyes need vitreo retinal surgery. Detachments with large break or posteriorly placed breaks or not visible breaks or those associated with membranes formed over or under retina (which produces stiff in folding or wrinkling of retina) needs vitreo- retinal surgery. In VR surgery Vitrectomy is done along with very delicate retinal procedures such as removing of stiff membranes from over or under surface of retina, draining out fluid from under the retina & lasering retina. These surgeries invariable require placing of silicon oil or gas inside vitreous cavity to push retina against outer layers of eyeball, thus helping re-attachment.
Diseases involving Vitreo retinal interface— like membrane formation on macula with tractional pull or macular hole formation. In case of IOL or natural lens falling back into vitreous.