Early diagnosis and treatment of senile macular degeneration (AMD) allows patients to avoid blindness, thereby significantly reducing the costs associated with disability – told PAP Prof. Paul Mitchel from the Medical University of Sydney.
Prof. Mitchel, an authority in the field of AMD treatment, is a guest of the 43rd Congress of Polish Ophthalmologists, which takes place in Warsaw on June 10-13.
As the professor pointed out in an interview with PAP, the economic costs of losing sight are huge. For example, in our research, we’ve shown that visual impairment alone is associated with a higher risk of depression, falls and fractures, and dependence on social care. All this puts a heavy burden on the state budget, so it is more profitable to invest in early diagnosis and effective treatment of AMD – said Prof. Mitchel.
There is currently one approved drug, ranibizumab, for the so-called a wet form of AMD that quickly leads to blindness. Using it can hinder the progression of the disease and save your eyesight. However, Polish patients still do not have access to it, because the drug is expensive, and work on the implementation of a therapeutic program – allowing ranibizumab to be reimbursed for a certain group of patients – has stalled. The reason for the stagnation is too low valuation of the drug and the procedure proposed by the National Health Fund, which would lead to indebtedness of the institutions implementing the program or force them to administer the drug in non-therapeutic doses.
Prof. Mitchel recalled that most European countries, including the Czech Republic and Hungary, decided to reimburse ranibizumab.
Age-related macular degeneration (AMD) affects the retina of the eye, specifically its central part – the so-called macula – responsible for sharp and precise vision of details and colors. At the initial stage of AMD development, drusen (i.e. deposits) and pigmentation changes appear in the retina – explained Prof. Mitchel. 85 percent AMD cases remain at this initial stage of development, and 15 percent. goes into advanced form – 10 percent in the so-called exudative, and 5 percent. in atrophy. As the disease progresses, there are difficulties with clear vision in the central field and significant distortions of the image. In advanced characters, patients with AMD have problems recognizing the face because they see the blot instead of it, are unable to read, or even do simple housework such as slicing bread. The disease is considered to be one of the most important causes of blindness in people over 50.
Prof. However, Mitchel emphasized that early detection of the initial changes typical of AMD allows for interventions that can prevent progression to the advanced form. It is all about absolutely quitting smoking and implementing a proper diet – explained the specialist.
Many studies show that eating fish plays an important role in the prevention of the wet form of AMD, due to the unsaturated omega-3 fatty acids it contains. The work that prof. Mitchel published in 2009 arguing that eating fish at least once a week can halve the risk of developing wet AMD in people with a variant of the disease-predisposing gene.
This indicates that gene and environmental interactions are involved in the development of AMD. Therefore, knowing the genetic predisposing factors, we can modify the lifestyle elements of people with early degenerative changes in the retina in such a way as to prevent the further development of the disease – said Prof. Mitchel.
The most important risk factors for advanced AMD are age (the risk grows very quickly after the age of 60) and smoking (smokers are several times more likely to develop AMD and develop the advanced form 10 times earlier). AMD is also more common in obese people and in those who have had cataract surgery.
In the early form of the disease, most patients do not have any noticeable symptoms, so the most effective diagnosis is fundus examination to detect macular degenerative changes.
In our clinic, we ask patients with such early lesions to perform the Amsler test once a week to help detect visual disturbances associated with the wet form of AMD, said Prof. Mitchel.
The test consists in looking – after covering one eye (in the case of wearers of glasses it is done with glasses) – at a piece of paper covered with a grid of lines. If a patient notices curved lines or scotomas in the central field of vision, it is a sign that they should contact their ophthalmologist as soon as possible. Then, fluorescein angiography is performed to assess the condition of the retinal blood vessels – explained the ophthalmologist.
In his opinion, the early detection of disease progression towards wet AMD is very important, because using ranibizumab can stop this process and prevent blindness.
It works by blocking the vascular endothelial growth factor (VEGF). In the wet form of AMD, pathological – brittle and leaky – vessels appear under the retina. This is the cause of subretinal edema and haemorrhage which destroy the macula.
There is currently no effective therapy for atrophic AMD. Doctors are trying to use dietary supplements that protect cells against excess free radicals, such as lutein and preparations that improve blood circulation in the retina (PAP).