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Dislocation and subluxation of the lens: causes, symptoms, diagnosis, treatment
Last reviewed: 07.07.2025
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Dislocation of the lens is a complete detachment of the lens from the supporting ligament and its displacement into the anterior or posterior chamber of the eye. This causes a sharp decrease in visual acuity, since a lens with a power of 19.0 diopters has fallen out of the optical system of the eye. The dislocated lens is subject to removal.
Subluxation of the lens is a partial rupture of the zonular ligament, which can have varying circumferential length.
Congenital dislocations and subluxations of the lens are described above. Acquired displacement of the biological lens occurs as a result of blunt trauma or severe concussions. Clinical manifestations of lens subluxation depend on the size of the resulting defect. Minimal damage may remain unnoticed if the anterior limiting membrane of the vitreous body is not damaged and the lens remains transparent.
[ Symptoms of lens dislocation and subluxation
The main symptom of lens subluxation is iris tremor (iridodonesis). The delicate tissue of the iris rests on the lens at the anterior pole, so the tremor of the subluxated lens is transmitted to the iris. Sometimes this symptom can be seen without using special examination methods. In other cases, it is necessary to carefully observe the iris under lateral lighting or in the light of a slit lamp to catch a slight wave of movement with small displacements of the eyeball. With sharp deflections of the eye to the right and left, slight oscillations of the iris cannot be detected. It should be noted that iridodonesis is not always present even with noticeable lens subluxations. This occurs when, together with a rupture of the Zinn ligament in the same sector, a defect appears in the anterior limiting membrane of the vitreous body. In this case, an incarcerated hernia of the vitreous body occurs, which tamponades the resulting hole, reducing the mobility of the lens. In such cases, lens subluxation can be recognized by two other symptoms revealed by biomicroscopy: uneven depth of the anterior and posterior chambers of the eye due to more pronounced pressure or displacement of the vitreous body forward in the area of weakened support of the lens. In case of a pinched and fixed by adhesions hernia of the vitreous body, the posterior chamber in this sector increases and at the same time the depth of the anterior chamber of the eye changes, most often it becomes smaller. Under normal conditions, the posterior chamber is not accessible for examination, therefore the depth of its peripheral sections is judged by an indirect sign - different distances from the edge of the pupil to the lens on the right and left or above and below.
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Treatment of dislocation and subluxation of the lens
With uncomplicated lens subluxation, visual acuity does not decrease significantly and treatment is not required. However, complications develop over time. The subluxated lens may become cloudy, or it may cause secondary glaucoma. In such cases, the question of its removal arises. Timely diagnosis of lens subluxation allows you to choose the right surgical tactics, assess the possibility of strengthening the capsule and placing an artificial lens in it.