What is intraocular lens dislocation?
Intraocular lens (IOL) dislocation is a very rare condition that affects patients who have undergone cataract surgery and consists of the displacement of the implanted lens towards the vitreous cavity of the eye. On other occasions, the lens becomes decentred from the visual axis but does not fall into the vitreous cavity (subluxation).
Displacement of the intraocular lens causes changes to vision and, if it falls into the vitreous cavity, it can produce traction due to the eye’s own movement, resulting in retinal detachment and/or vitreous haemorrhage.
What causes it?
It is estimated that between 0.05% and 3% of patients who have undergone cataract surgery will suffer from a spontaneous dislocation of the IOL. Some studies show that its incidence is higher 5 years after surgery.
Sufferers usually have the following disorders or previous procedures:
- Crystalline pseudoexfoliation syndrome (PSX), which consists of breakage of the fibres of the ligaments that support the natural lens of the eye (zonule).
- High myopia
- Previously performed surgical procedures, such as glaucoma and vitrectomy
- Eye injuries
How can it be prevented?
IOL dislocation cannot be prevented as it occurs spontaneously. It is important, however, for patients who have undergone cataract surgery to have regular check-ups and urgently visit the ophthalmologist if they notice any loss of vision.
The most characteristic symptom of IOL dislocation is loss of vision, although some patients also complain of blurred or unfocused vision. It does not cause pain.
If the lens is in the vitreous cavity, treatment consists of performing a vitrectomy in order to remove it and implant another or reposition it. In cases where the IOL has not fallen into the vitreous cavity, the surgeon can simply reposition it without the need to perform a vitrectomy.