Do you have myopia or suffer from myopic vision? Did you know that having high myopia or severe short-sightedness is a risk factor for retinal degeneration later in life? Myopia, which is typically due to an elongation of the eyeball, leads to stretching and thinning of our retina. Depending on the severity of myopia (how high the degree of short-sightedness), our retina may be affected in various ways. In this article, we discuss Myopia Degeneration and see how the eye due to myopia can lead to vision loss.
What is Myopia Degeneration?
This is a condition where progressive stretching of the eye from myopia leads to eventual damage to the part of the eye that allows us to see. The retina is found on the back of the eye and is responsible for capturing light that enters the eye. Damage to the retina, caused by the stretching can lead to a variety of conditions or further complications. The main resultant symptoms to the patient are then observed to be loss of vision.
Persons with high myopia or severe short-sightedness are at higher risk of developing myopic degeneration simply due to the degree of elongation of the eye.
Myopic degeneration is known to commonly occur during young adulthood, although the exact causes of this eye disease are not clearly understood. However, theory suggests that the retina in an eye with high myopia (which is shaped long from a normal eye) is stretched over an area larger than what is normal. Over time, the forces within the eye such as internal eye pressure may cause the outer coat of the eye (the sclera) to stretch and move. This movement or stretching is thought to bring about the damage to the retina which is characteristic of myopic degeneration. Left untreated, myopic degeneration may result in other conditions in the eye such as choroidal neovascularization and may lead to a permanent loss of central vision.
Dangers of Myopia Degeneration
Central retinal stretching and thinning may lead to macular staphylomas, macular geographical atrophy, myopic lacquer cracks and even myopic macular choroidal neovascularization which may eventually lead to myopic macular degeneration. What does this all mean? It means that the macula (or central retina) within the eye may degenerate to a stage of atrophy (loss of photoreceptors), may crack resulting in retinal bleeding or further complications.
There are cases where the elongation of the eyeball causes damage to the central part of the retina (known as the macula), and may result in lacquer cracks and allow the growth of new blood vessels into the retina. The growth of these new blood vessels is known as choroidal neovascularization. These blood vessels may leak blood and affect the way light travels through to the back of the eye, resulting in distortion or loss of vision. Doctors term this condition as ‘Myopic Macular Degeneration’.
Myopic Macular Degeneration is seen as a serious condition and not to be taken lightly, as vision loss due to damage to the retina and macula will be irreversible. Early treatment is required to manage and halt the condition from progressing further. Without treatment, the vision loss (especially central vision) due to myopic macular degeneration may then pose inconveniences or dangers to the daily life of the patient.
Myopic degeneration is also dangerous simply because the early symptoms of retinal or macular degeneration are gradual. Despite loss of central vision, peripheral vision is hardly affected and the result is still a quality of vision that is highly functional at the early onset.
Statistically, persons suffering from high myopia are at a greater risk of developing myopic macular degeneration and other conditions such as retinal detachment.
Surgery may be necessary for to control symptoms
Apart from myopic degeneration or macular degeneration, the central retinal stretching due to myopia may lead to other conditions as well, such as Myopic Epiretinal Membranes, Myopic Macular Holes and Myopic Macular Schises. These conditions require surgical treatment to relieve the vitreous traction brought about by the excessive stretching, and to prevent further damage to the eye and vision of the patient.
In some cases, the stretching of the retina brought about by myopia may lead to peripheral retinal stretching. This stretching of the peripheral retina can progress into peripheral retinal degeneration such as lattice degeneration which may lead to retinal holes and tears.
Untreated, retinal holes and tears in the eye may lead to unwanted retinal detachment and sudden vision loss.
Prevention and regular checkup
As these degenerative changes are often asymptomatic until it is too late, it is prudent for those with high degrees of short-sightedness to get checked regularly for such conditions. This is especially so for myopic degeneration patients.
Most people don’t realise that we should see the eye doctor routinely every year to maintain our eye wellness (similar to how we should see our dentists annually as well). Even more importantly, it is beneficial for us to try to prevent myopia increase in our children to avert these conditions completely.