The first step in any treatment for diabetic eye disease is to maintain blood glucose, blood pressure, and blood cholesterol levels as close to normal as possible.
Treatment of diabetic macular edema (swelling or the accumulation of blood and fluids in the macula, the part of the retina that provides sharp central vision), has evolved a great deal in the last five to ten years, and is based on the severity of the edema. At present, there are three options:
- laser treatment
- Avastin, Lucentis, or Eylea injection
- intravitreal steroids: Kenalog, Ozurdex, and Iluvien
This technique is used by retinal surgeons to treat a number of eye conditions, one of which is diabetic eye disease. A beam of high-intensity light is directed into the eye to seal off leaking blood vessels and prevent additional blood and fluid from leaking into the vitreous, which is the jelly-like substance that fills the inside of the back part of the eye. The doctor administers eye drops to dilate (open up) the pupil and numb the eye before treatment begins.
Because lasers cannot restore lost vision, it is critical to maintain regular comprehensive eye examinations so that treatment can be initiated as soon as diabetic eye changes are detected. There are two types of laser treatments for diabetic eye disease:
- Focal laser treatment, also called photocoagulation: The retina is treated to stop or slow the leakage of blood and fluid from abnormal blood vessels within the eye. Focal laser, however, can also destroy surrounding healthy retinal tissue as it seals the leakage from abnormal blood vessel growth; therefore, it is not used on blood vessels directly under the macula, the center of the retina.
- Scatter laser treatment, also called panretinal photocoagulation: The areas of the retina away from the macula are treated to shrink abnormal blood vessels.
Avastin, Lucentis, or Eylea Injections
In diabetic eye disease, abnormal blood vessels develop that can break, bleed, and leak fluid. If left untreated, these damaged blood vessels can result in a rapid and severe loss of vision. The most effective treatments to date for this blood vessel damage are the anti-angiogenic drugs Avastin, Lucentis, and Eylea.
Angiogenesis is a term used to describe the growth of new blood vessels and plays a crucial role in the normal development of body organs and tissue. Sometimes, however, excessive and abnormal blood vessel development can occur in diseases such as cancer (tumor growth) and diabetic eye disease (retinal and macular bleeding).
Substances that stop the growth of these excessive blood vessels are called anti-angiogenic (anti = against; angio = vessel; genic = development), and anti-neovascular (anti = against; neo = new; vascular = blood vessels).
The focus of current anti-angiogenic drug treatments for diabetic eye disease is to reduce the level of a particular protein, called vascular endothelial growth factor or VEGF, that stimulates abnormal blood vessel growth in the retina; thus, these drugs are classified as anti-VEGF treatments.
At present, Avastin, Lucentis, and Eylea are administered by injection directly into the eye after the surface has been numbed. The needle is very small and is inserted near the corner of the eye – not the center. During the injection procedure, the doctor will ask the patient to look in the opposite direction to expose the injection site, which also allows the patient to avoid seeing the needle.
These drugs are powerful. The abnormal vessels will disappear within 24 to 48 hours; however, the vessels are not gone forever. They will come back, since the effect of the drug will wear off. The half-life of the drugs in the eye is about four to six weeks. Treating edema with these drugs requires frequent injections.
Steroids are very good at treating the swelling caused by diabetic macular edema. Like Avastin, Lucentis, and Eylea, the steroid is injected into the vitreous, the jelly-like substance that fills the inside of the back part of the eye (intra = into; vitreal = vitreous gel). Steroids are powerful drugs that can reduce retinal edema dramatically; however, they also have side effects that can be significant.
The use of steroids to treat eye disease is associated with the development of glaucoma and cataracts in some patients. Nevertheless, steroid treatment can be a useful tool and can be combined with both anti-VEGF injections and laser to control difficult cases of diabetic macular edema.
In the past, steroids were injected in crystalline form into the eye and then were gradually absorbed by the body over 4-6 weeks. There are now two new steroid medications that have been FDA-approved for the treatment of diabetic macular edema that can deliver drug to the eye for a much longer period of time. The steroid medications currently available are:
- Kenalog (generic name triamcinolone): crystalline solution
- Ozurdex (generic name dexamethasone): implant injected in the doctor’s office that is active for 3-4 months
- Iluvien (generic name fluocinolone acetonide): implant injected in the doctor’s office that is active for up to 36 months. This medication currently is approved only for treatment of diabetic macular edema in patients who have been treated previously with a course of corticosteroids and did not have a clinically significant rise in intraocular pressure (IOP).
- You can read more about the FDA approval process for Iluvien at The FDA Approves Injectable Implant ILUVIEN for Treatment of Diabetic Macular Edema on the VisionAware blog.
Repair of Retinal Detachment
Many diabetic tractional retinal detachments develop slowly and are different from a typical retinal detachment that develops overnight. A tractional retinal detachment occurs when fibrous tissue, caused by an injury, inflammation, or the growth of abnormal blood vessels, pulls the retina away from the underlying tissue layers. The goal, therefore, is to repair the retina before the macula, which provides sharp central vision, detaches.
A technique called vitrectomy is used to repair a retinal detachment. A vitrectomy is a surgical treatment in which a doctor makes an incision in the eye and uses a small instrument to remove the gel and the blood that have accumulated in the vitreous as a result of retinal bleeding. The procedure is performed under local or general anesthesia.
The vitreous gel is then replaced with a saline (or salt) solution. After removing the vitreous gel, the surgeon may treat the retina with a laser, cut or remove fibrous or scar tissue from the retina, or repair tears or holes in the retina.
Article shared from VisionAware – For independent living with vision loss.