Diabetes Mellitus is a condition that results from the inability of the body to effectively utilize sugar. Diabetics will thus have excessive sugar in the blood and excrete it in urine. It is a metabolic defect wherein heredity and environmental factors may be responsible. Diabetes Mellitus can affect anyone at any age. Persons with affected family members and those with excessive weight are high-risk individuals. Young children may also be affected in the juvenile type of diabetes. Diabetes Mellitus can be effectively controlled but cannot be cured.
Why is this disease important?
The latest report of World Health Organization (WHO) states that India will have over 50 million people with diabetes by 2025. Among these 50 million, approximately 20 million will have Eye diseases due to diabetes.
How does diabetes affect the eye?
Diabetes Mellitus is a disease, which affects tiny blood vessels in the body. The eyes have many small blood vessels like the Kidney and Heart and can also be affected by diabetes mellitus. Diabetic Retinopathy, Diabetic Cataract, and Diabetic Neuropathy are the conditions affecting the eye due to this disease. Damage to the optic nerve can result in loss of vision while damage to the nerves supplying the muscles can lead to double vision. Glaucoma (Increased pressure in the eye) may also, result from diabetes.
When should a Diabetic patient have an eye check up?
Diabetics should have their eyes examined as soon as they are diagnosed to have diabetes. They should not delay until decrease in vision is noticed. Diabetic eye diseases can co-exist with good eyesight. Regular follow up visits with Diabetologists and Ophthalmologists are important.
What is Diabetic Retinopathy?
It is important to know what is retina, before we understand diabetic retinopathy. The Retina is a light sensitive layer on the back of the eyeball. It is the site where light rays entering the eyes are converted into chemical and electrical impulses, which are carried to the brain. The brain cannot see if the Retina is damaged. The retina has many tiny blood vessels, which supply its nutrition. When diabetes mellitus affects these tiny blood vessels, gradual or sudden loss of vision occurs. Initially tiny haemorrhages, fatty deposits, retinal swelling and closure of the tiny blood vessels are responsible for the defective vision. As the disease progresses the blood supply to the retina gets worse. The Retina may, as a natural response, try to form new blood vessels, which may bleed extensively and produce sudden loss of vision. Repeated bleedings, in the eye can induce the development of band like tissues, which may pull the retina from its bed leading to profound loss of vision. The irreversible blindness with diabetic retinopathy is on the increase worldwide. It is partly due to ignorance and irregular treatment.
How Diabetic Retinopathy is diagnosed?
Apart from the basic eye examination, a thorough fundus examination after dilatation of pupil by indirect ophthalmoscopy is necessary to diagnose diabetic retinopathy. If all the required information cannot be obtained by clinical examination, an investigation called F.F.A (Fundus Fluorescein Angiography) is advised in diabetic patients.
What is the treatment available for diabetic retinopathy?
In the early stages of diabetic retinopathy, Argon Laser Photocoagulation is used to control the disease and maintain the existing vision. Depending upon the severity of the disease each eye may be given One to Four sittings of Laser treatment. Patients have to come for periodic eye check up even after treatment and also follow their physician's advice regarding control of Blood Sugar. Laser treatment is an out-patient procedure wherein the patient is asked to sit in front of the equipment and light rays (Laser beam) are passed through a special lens to destroy the defective area in the retina.
Retinal Vascular Diseases
Hypertensive Retinopathy refers to the changes in the retina and its blood vessels due to long standing Hypertension. The small arterioles of retina are particularly prone to damage due to hypertension. The changes include narrowing of arterioles, thickening of vessels walls and leakage, which may lead to significant decrease in vision. Adequate control of blood pressure can reverse these changes and prevent further visual loss. Periodic eye check up is also important to detect evidence of retinopathy at the earliest and to institute timely treatment. Retinal venous occlusions can involve the central retinal vein or any of its tributaries. Important risk factors include increasing age (usually seen in 6th and 7th decade), systemic hypertension and blood dyscrasias. Occlusion of retinal vein leads to the leakage of blood and fluid into the retina resulting in symptoms like decreased or distorted vision, black spots, and floaters. Diagnosis is based on Indirect Ophthalmoscopy and Slit-lamp biomicroscopy. Fundus Flourescien Angiography is performed to detect if any complications have developed. It is advised to wait for 2-3 months for the spontaneous resolution of haemorrhages and retinal edema (swelling). If abnormal blood vessels (neovascularisation) develop on the disc or in the retina, Laser photocoagulation (Using Argon laser or Diode laser) is done to destroy them and prevent further bleeding, thus maintaining existing vision. Surgery is rarely indicated, if there is un-resolving vitreous haemorrhage or retinal detachment. Most important is treatment of causative factor, if any. eg: Treatment of hypertension or blood dyscrasias
Central Retinal Artery occlusion causes sudden and profound loss of vision. This is one of the true OCULAR EMERGENCIES and if appropriate treatment is instituted within 24-48 hrs, vision can be restored.
Eales' Disease is characterized by inflammation and occlusion of peripheral retinal vessels, resulting in poor blood supply to the retina. This leads to the formation of abnormal blood vessels on the retina, which has increased tendency to bleed. Exact cause is not known. Tuberculosis has been considered as an etiological factor, but not fully proven. Usually seen in men of 20-30 years of age. Both eyes may be affected. Patients presents with sudden decrease in vision due to bleeding inside the eye. Diagnosis is based on clinical examination findings. Fundus Fluorescein Angiography is helpful to assess the extent of ischemia and to identify the new vessels. Treatment include steroids (to control vasculitis), laser photocoagulation (to destroy new vessels and prevent bleeding) and Vitrectomy (if there is retinal detachment). Visual prognosis is good in most cases. Retinal diseases associated with Blood Dyscrasias like Anemia, Leukemia, Sickle cell anemia etc. can result in proliferative changes in the retina with formation of abnormal blood vessels and haemorrhages. Treatment of underlying cause is most important. Laser photocoagulation helps to arrest bleeding and prevent further visual loss.
AGE RELATED MACULAR DEGENERATION(ARMD) Age related macular degeneration is a disorder of the central retina called the macula, that usually affects patients of 60years of age and older. The macula is essential for clear vision. Its deterioration results in slowly progressive visual loss that cannot be halted effectively. Two types of Age related macular degeneration are described:
1. Dry or atrophic form
Characterized by yellowish subretinal deposits called Drusen and areas of atrophy of retina and underlying structures.
2. Wet or Exudative form
Characterized by leakage of fluid and blood into I under the retina from abnormal blood vessels which develop beneath the retina called Choroidal Neovascularisation. Symptoms include decreased I distorted vision, central scotoma or floaters. Diagnosis is based on dilated fundus examination using Indirect Ophthalmoscope and fundus lenses. FFA is essential to confirm the diagnosis and to plan treatment. Those with atrophic form of ARMD are advised to monitor their central vision using Amsler grid. Exudative form of ARMD with Choroidal neovascular membrane warrants immediate treatment. If the membrane is situated outside the fovea it is destroyed by laser photocoagulation. Newer modalities like Transpupillary Thermotherapy (TTT) and Photodynamic Therapy (PDT) may be required for membranes located underneath the fovea. TTT is a technique, which involves prolonged application of low energy, infrared laser to photocoagulate areas of neovascularisation by increasing retinal temperatures. Since photocoagulation of surrounding normal tissues is minimized, TTT is found to maintain good visual function in these patients.
Hereditary retinal dystrophies
This includes a group of hereditary disorders characterized by difficulty with night vision(night blindness) and loss of peripheral vision. Poor central vision and difficulty with colour vision may ensue. Fundus examination and special test called "Electroretinogram" which measures the electrical activity of the retina are done to diagnose this condition. . TOXIC RETINOPATHIES Drugs known to cause retinal toxicity include Antimalarial drugs (choloroquine, hydroxycholoroquine and quinine), Phenothiazines (chlorpromazine and thioridazine used as sedatives and in the treatment of schizophrenia) Tamoxifen (anti-estrogen used in patients with breast carcinoma).Retinaltoxicitydevelops onlywithhighdoses over a prolonged period. Patients may complain of decreased vision and central scotoma. If toxicity is suspected, the drug should be discontinued.
Retinal Surgery :
When does a person require surgery for retinal diseases?Certain retinal emergencies like retinal detachment or tractional retinal detachment involving the macular or a combined retinal detachment or in cases of penetrating trauma or in certain serious sight threatening infections, Vitreo - retinal surgery needs to be done on an emergency basis. In certain other conditions like diabetic vitreous hemorrhage or retinal detachment with proliferative vitreo retinopathy (long standing retinal detachment), in certain inflammatory conditions, which cause vitreous hemorrhage (Eale's disease), in the management of epiretinal membranes or macular hole cases, retinal surgery can be taken up on an elective basis.
Can Surgery be avoided?
Yes, in certain conditions, if the patients present very early with lattice degeneration with retinal hole or retinal tear and patients with diabetic retinopathy before the onset of complications like vitreous hemorrhage require prompt and adequate treatment with lasers and surgery can be avoided for these problems.
Laser Photocoagulation
Laser treatment forms a very important and indispensable modality of treatment for retinal diseases especially for diabetic retinopathy, vasculitis and for the treatment of Age related macular degeneration. Lasers are also used for treating retinal tears, retinal holes or lattices. Lotus is equipped with three different types of lasers of different frequencies for optimum treatment of the eye diseases.
Argon Green Laser -
It is a blue green laser for treatment of Diabetic retinopathy, vasculitis, retinal tears and hole.
Diode Laser -
It is an infrared laser for the treatment of Diabetic retinopathy, vasculitis, retinal tears, hole and for endo laser.
Transpupillary Thermo Therapy facility
It involves using a diode laser for the treatment of Age related macular degeneration.
What should I know before undergoing a Retinal Surgery?
The patient should be aware of .
- The nature of the problem.
- The type of surgery, which is planned.
- The visual prognosis, which is expected.
- The possibility of any recurrence of the disease process and If so, their management modalities. Need for repeat surgeries.
- The duration of post operative care, any head positioning to be adopted and the frequency of follow up.
Scleral buckling
It involves a procedure by which the hole or retinal break is localized treated with cryopexy and the subretinal fluid drained. A scleral buckle (implant or explant) is subsequently placed over the hole. It is very important that the patient undergoes surgery at the earliest for better visual activity.
Parsplana Vitrectomy
Vitreous is a jelly like substance filling the cavity within the eye. It could be site of collection of blood and formation of membranes pulling the retina from its bed. The separation of the jelly from the retinal surface leads to separation of the retina from its bed and also bleeding in to the vitreous cavity causing vitreous haemorrhage. Vitrectomy therefore helps to remove the blood, infected material and membranes from the vitreous cavity. Retinal Surgeries are complex surgeries, which have good prognosis if the patientundergoes surgery early. Delay in presentation leaks to formation of membranes called Proliferative Vitreo Retinopathy (PVR), which causes traction bands pulling the retina off.These sort of cases require sophisticated methods like Vitrectomy + Membrane Peeling + an addition of a tamponading agent like Silicon oil or intraocular gas, which keeps the retina attached for a sufficient period of time to enable the retina to get attached permanently. The silicon oil can be subsequently removed at a later date. At Lotus, these surgeries are now done on a routine basis.
Vitreo Retinal Unit
Lotus Eye Care Hospital is equipped with sate of the art and fully functioning vitreo retinal unit dealing with a range of complicated retinal emergencies. It includes a separate vitreo retinal theatres with sophisticated retinal microscopes and state of the art vitrectomy machine and other accessories like Endo lasers, Membrane pealing and adjuvants like silicon oil, liquid perfluoro carbons and intraocular gas. The theatre is also equipped with a digital video recorder to record video recording and presentations.
Diabetic Eye Unit
Diabetic Eye Unit established at Lotus aims to provide world-class care for diabetic patients. State of the art equipments in the unit include TOPCON IMAGENET 2000 for digital Fundus Fluroscein Angiography (FFA) and Sonomed A & B Scan for ultrasound scanning of the eye. Laser treatment of diabetic retinopathy is done with Argon Laser (Crystal Focus, France), Diode Laser (Quantel Medical, France) and Vag Laser (Laserex). There is a separate operation theatre equipped with high-tech vitrectomy machines and instruments for performing vitreo-retinal surgeries. Three retinal experts are available to examine and treat patients with diabetic retinopathy.
Life Time Vision
This is an innovative project started by Lotus Vision Research Trust and Lotus Eye Care Hospital, to guide and help diabetic patients to retain vision for the lifetime .
Objectives :
- Maintain constant touch with diabetic patients
- Provide proper education and awareness for early eye examination and timely treatment.
- Emphasize the importance of good diabetic control and taking proper treatment for other risk factors like Hypertension.
- Conduct awareness programmes through IMA, Lions club, Rotary club etc.
- Conduct screening eye camps in rural areas by medical and paramedical team.
- Provide concessional treatment to those who cannot afford the full cost of treatment.
- Provide completely free treatment for the genuinely poor diabetic patients.
- The second part of the programme to conduct population based survey and the details will be handed over to the relevant authorities for follow up.
|
