In myopia (synonyms: Axial myopia; Refractive myopia; Fundus myopicus; Functional myopia; Congenital myopia; Myopia magna; Myopia; Progressive myopia; ICD-10-GM H52.1: Myopia) is myopia of the eye. By definition, this refers to a mismatch between the refractive power and the axial length of the eyeball, causing the incident rays to meet at a focal point in front of the retina. This leads to the fact that on the retina only a blurred picture is shown. Thus, only objects close to the eye can be seen sharply.
Myopia is defined in different ways:
- Presence of at least -0.75 diopters in both main meridians of the cornea.
- Purely spherical refractive deficit of -0.5 diopters
One can distinguish benign (benign) myopia (myopia simplex; school myopia) from malignant (malignant) myopia (myopia magna or myopia progressiva; rare):
- Benign myopia; myopia usually begins between the ages of 9 and 13 (mild to moderate myopia; up to -6 diopters)
- Benign progressive myopia, is a myopia still progressing until the age of 30 (up to -12 diopters).
- Malignant myopia, is a further increasing myopia, even at an older age.
Furthermore, myopia can be distinguished between:
- Axis myopia – too long eyeball and normal refractive power (80% of cases of myopia).
- Refractive myopia – normally long eyeball and too much refractive power; there are the following special forms:
- Myopic sclerosis of the lens nucleus in old age.
- Keratoconus – change in the shape of the cornea, which leads to an increase in the refractive power of the cornea.
- Spherophakia – spherical shape of the lens.
Frequency peak: the maximum occurrence of myopia is between the 9th and 13th year of life.
The prevalence (disease frequency) is 35-40% (in Germany).
Course and prognosis: At the beginning of myopia, the affected person notices the first signs mainly at night – vision in the darkness becomes worse. The course of the disease is progressive, but in most cases it comes to a halt (depending on the form of myopia, see above). Near-sighted people have an increased risk of ablatio retinae (retinal detachment) in the course of their refractive error. In addition, wearing contact lenses can damage the cornea (cornea). Consequently, individuals should have their eyes examined regularly by an ophthalmologist.
