Contrast sensitivity testing
The macula is the central area of the retina and back of the eye and it’s the maximum point of vision. The integrity of the macula allows you to enjoy clean central vision, distinguish details, read and recognise, for example, people's faces.
Macular oedema is a common pathology and involves an anomalous accumulation of liquid or “waterlogging” in the macular area due to a change in the permeability of the blood vessels irrigating it.
It is usually painless but manifests itself with blurry central vision, distortion or undulation of images, alteration of colours (washed-out or different appearance) and difficulty in reading.
There are different eye pathologies that may cause a macular oedema, including diabetic retinopathy (the most common), thrombosis or retinal vein occlusion, uveitis (intraocular inflammation), post-eye surgery, retinal dystrophy like retinitis pigmentosa, age-related macular degeneration, intraocular tumours, traction phenomenon like epiretinal membrane (tissue that grows on the macula surface and changes its normal morphology), even in relation to the use of certain topical eyedrops for the treatment of glaucoma (prostaglandin analogues).
There are different options for treating macular oedema, depending on the patient and the cause of the oedema, as well as the degree of severity thereof. It is fundamental to personalise the best treatment in each case.
In some cases, using anti-inflammatory eyedrops may suffice. Another type of treatment is based on drug injections in the periocular area (around the eyeball) and intraocularly (injecting the medication into the eye). These drugs—corticosteroids or angiogenesis inhibitors—act locally on the macula to reduce inflammation and fluid extravasion. Laser photocoagulation is also useful in the treatment of some cases of macular oedema by “sealing” the points where the fluid is escaping. Finally, in some cases vitreoretinal surgery is required to treat traction macular oedema, where there is tissue on the surface of the retina responsible for changing the macula.
The different prevention strategies will depend on the cause of the macular oedema.
People with diabetes must insist on good control of their metabolism and blood sugar, taking into account that this complication may appear during any phase of diabetic retinopathy and not just at advanced stages.
Given that macular oedema is, in many cases, associated with vascular diseases, adopting a healthy lifestyle is also recommended (healthy food, regular exercise...) to avoid predisposing factors like high blood pressure and high cholesterol.
Likewise, to avoid irreversible damage to the macula, it is important to undergo regular eye check-ups for an exhaustive study of the back of the eye and its blood vessels, so that any anomalies can be detected early. In this regard, an annual check-up is advised even if you don't have any symptoms.
Frequently asked questions
The most common clinical method for determining the presence or macular oedema (or the lack thereof) is a clinical examination with a slit-lamp and a dilated pupil. However, complementary imaging tests are often necessary like an optical coherence tomography, which enable an evaluation of the changes in the thickness or morphology of the macula to be assessed in very high definition and allow us to do a follow-up on the response to the treatment. The fluorescein angiography, a medical procedure in which a fluorescent dye is injected into the bloodstream and photographs are taken of the back of the eye, is also a useful test for evaluating retina circulation and for the study of the causes of macular oedema.
In general, these cases have a good prognosis. The large majority of these patients usually get better simply by using anti-inflammatory eyedrops, meaning the macular oedema disappears within a few weeks. Cases that do not respond to topical treatment with eyedrops do generally respond well to local corticosteroid injections with considerable visual recovery and a good prognosis.