BLOOD SUGAR CONTROL
Controlling your blood sugar and blood pressure is most importantin preserving vision. Patients should carefully follow the diet plan as per the dietician’s recommendation and should take the medicine as per the physician’s prescription. Controlling the blood pressure keeps the eye’s blood vessels healthy.
These include Avastin, Eylea, and Lucentis& help to reduce swelling (oedema) of the macula, slowing deterioration in vision and often improving vision. This drug is delivered by injections in the vitreous (jelly of the eye).This works by interfering with chemicals that encourage leakiness of the retinal blood vessels at the macula&helps; to reduce the swelling of macula and prevents further damage.
DIABETIC MACULAR EDEMA (DME) LASER TREATMENT
In diabetes, Diabetic maculopathy is the most common cause of visual loss. The 2 main types of maculopathy are diabetic macular edema (DME) and macular ischemia.
In DME, the retinal blood vessels leak fluid, which causes thickening and swelling in macula. It can be treated with laser and intravitreal injections. In macular ischemia, thin retinal capillaries to the macula close and the macula does not receive sufficient blood supply. Unfortunately, there is currently no effective treatment for macular ischemia.
This is the main laser treatment for maculopathy from DME. The laser seals blood vessels that are leaking fluid and blood in the retina. This reduces further fluid and blood leakage, and reduces the swelling of macula. Also, the retinal laser may also stimulate the retinal cells to ‘pump’ away the excess fluid at the macula.
Laser is only required for the patients with vision worse < 20/40 and clinically significant macular edema (CSME). The important point to remember is that the aim of laser treatment is to prevent vision from getting worse& not to improve it.
Focal retinal laser treatment is often combined with intravitreal injection of either steroid or anti-VEGF into the eye to improve outcomes in vision.
PROLIFERATIVE DIABETIC RETINOPATHY LASER TREATMENT
Proliferative diabetic retinopathy (PDR) is the most severe form of diabetic retinopathy. It is characterized by the growth of abnormal new blood vessels (neovascularization) in the eye which occurs as a natural response to the oxygen, nutrients-starved blocked retinal cells.
These abnormal fragile new vessels grow on the surface of the retina and into the vitreous gel. They can bleed easily into the vitreous cavity of the eye (vitreous hemorrhage) or can cause a pull on retina when they cause scar tissue formation which can lead to detachment ofthe retina (Tractional retinal detachment/TRD).
Pan-retinal photocoagulation (PRP)
The first line of proliferative diabetic retinopathy laser treatment is with PRP or scatter photocoagulation. This involves laser application on large areas of the retina with the aim of coagulating/burning the ischemic retinal cells in the periphery.
After PRP, the ischemic cells throughout the retinal periphery become replaced by scar tissue. This reduces the production of chemicals which stimulate neovascularisation.
If performed at the early stages, the abnormal new blood vessels may regress and eventually disappear completely eliminating the risk of bleeding or TRD. If performed only at the later stages, further abnormal new blood vessels will be prevented from forming but the existing abnormal vessels may not regress completely & the risk of vitreous hemorrhage, TRD is reduced but not eliminated.
As with focal laser treatment, PRP laser is also performed in the consulting OPD without the need for a hospital admission. After dilating and numbing the eyes (local anaesthesia), a contact lens is placed on the eye to stop blinking and to allow visualization.
Due to the extensive nature of the laser, it can be quite uncomfortable during laser. Taking some pain-relieving / anti-inflammatory medications before laser can decrease the discomfort. The PRP laser can be also done in 2 or 3 sessions to reduce the intensity of each session. If still intolerable, a sub-tenonanaesthesiainjection can be given around the eye to completely numb it.
Panretinal laser photocoagulation is also often combined with anti-VEGFs into the eyeball to improve visual outcomes.
This is another option to reduce macular swelling.
Laser is the mainstay of treatment for many retina disorders like Diabetic Retinopathy (DR), Vascular Occlusions, Age Related Macular Degeneration (ARMD) & vascular Malformations.
PAN-RETINAL PHOTOCOAGULATION (PRP)
It is a type of laser treatment used in patients who have developed new abnormal blood vessels in the retina. It prevents abnormal new vessels formation and encourages existing ones to shrink and scar which makes them less likely to bleed into the vitreous (vitreous haemorrhage) or to cause a painful high pressures within the eye (neovascular glaucoma).
PHOTO DYNAMIC THERAPY (PDT)
It is a newer modality for treatment of age related macular degeneration and is very useful for specific indications. It is a safe modality in cases where therapy is needed close to the fine vision area (fovea) of the retina.
Good scientific evidence suggests that laser treatment significantly reduces the risk of your vision deteriorating. It also reduces the risk of the eye developing painful high pressure.
The laser treatment can reduce the peripheral field of vision. Ask the doctor about the possible effects on this if you are a driver and will have to undergo a driving license/ renewal test. The night vision may be decreased and the colour vision may get altered in the eye. Rarely your vision may be worse after the treatment due to accumulation of fluid in retina (macular oedema), bleeding within the eye (vitreous haemorrhage) or by unintended burn to the centre of the retina.
Swelling at the macula i.e the fine vision area of the retina, known as Macular Oedema can be treated well with Anti-VEGF injections. Patients are being treated with the injections with great results. Anti-VEGF injections play a very important role in the treatment of following more common retina disorders :
- Diabetic Retinopathy
- Age Related Macular Degeneration (ARMD)
- CNVM due to other pathologies
- Venous Occlusive disease
The Anti-VEGF agents which have been routinely used are :
- Ranibizumab (Lucentis)
- Bevacizumab (Avastin)
- Pegaptanib sodium (Macugen)
- Aflibercept (Eylea)