What are diabetes and diabetic retinopathy?

Diabetes is understood as beinga disease thataffects the ability of the body to control its blood sugar levels. With time, high blood sugar levels may damage the small blood vessels of the eye, the liver and other organs.    
The retina is particularly sensitive to this disease. In the early stages of diabetic retinopathy deformities are caused in the smaller blood vessels, such as the microaneurysms, and tiny blood spots appear. This stage is known as the “non-proliferative” stage.
Various stages exist, from slight proliferative retinopathy to severe proliferative retinopathy. It is extremely important to track the evolution of the changes occuring in the retina in order to prevent retinopathy from developing into more serious proliferative forms, and this can be done by timely treatment and intervention.

When the small blood vessels (which under normal circumstances are impermeable and serve for the exchange of nutrients and oxygen) are affected by the disease, they may exhibit deformities and microaneurysms that lead to leakage of fluid, which accumulates in the retina as if this were a sponge, causing it to flood and enlarge and giving rise to blurring and loss of central vision. This alteration is known as macular edema.

What is diabetic macular edema treatment?

Should it go untreated, diabetic macular edema can with time permanently damage the layers of the retina. In order to arrest this seeping of fluid and consequent flooding of the retina, impacts of laser photocoagulation can be applied with great precision in the microaneurysms and affected vessels. On some occasions the laser photocoagulation treatment may not be effective, and in this case intravitreal injection of corticosteroids can help to reduce macular thickening and in many cases lead to a certain recovery of sight.

The recent emergence of antiangiogenic drugs, also administered by intravitreal injection, have had beneficial effects on some forms of diabetic macular edema, and are also used in more serious cases as a complement to surgery or photocoagulation.

Variations of diabetic edema exist in which thickening or deposits on the retina occur, which cause traction points and distorsions in the retina itself. Such cases are candidates for intraocular surgery with vitrectomy and freeing of these traction points and deposits, since treatment by drugs alone is insufficient to restore the normal shape and thickness of the retina.

These types of treatment are normally carried out repeatedly over time, since the disease has a tendency to recur. The treatment of diabetic macular edema and diabetic retinopathy is frequently effective in preventing greater loss of vision, but does not always result in improved sight.

How is diagnosis performed?

As a part of the ocular examination, we may need to take photographs and carry out fluorescein angiography of the retina, as well as performing optical coherence tomography in order to determine the degree of damage to the blood vessels and to assist us in deciding on treatment, in addition to analysing the results and monitoring the effects of the treatment carried out.

What is the treatment when the disease is in an advanced state (proliferative retinopathy)?

As retinopathy progresses, the abnormal blood vessels may grow through the surface of the retina. This stage, known as proliferative retinopathy, involves a high risk of vision loss due to severe intra-ocular hemorrhaging and complicated detachment of the retina, which is associated with abnormal proliferations of fibrous tissue and aberrant blood vessels. These cases require more highly aggressive laserphotocoagulation treatment in pheripheral areas of the retina and the most ischemically affected zones.
In advanced stages of the disease, vitrectomy surgery is necessary to remove intra-ocular blood, repair retinal detachment or liberate traction points caused by the aberrant tissue that grows on the surface of the retina and becomes detached. Microscopic, intra-ocular surgical instruments are used in vitrectomy, such as scissors, pincers, aspirators, illuminators, photocoagulators, etc..