An eye lens is a crystalline, disk-shaped component that brings light to focus on the retina, enabling the eye to see well. It's suited behind the pupil, which is the aperture or opening that controls the amount of light getting into the eye. The lens is held in position by bands of tissue known as the zonule of Zinn or suspensory ligament.
When the suspensory ligament is weak or broken/damaged, the lens can move out of its place, i.e., it's dislocated. The displacement can occur in any direction, e.g., to the side, up, down, or back, and the slippage can vary from minor to complete detachment. With the lens displaced, the eye can't focus correctly and that patients' vision is distorted. The condition can affect people at any age, including infants and toddlers, but it's more common in young adults below the age of 20.
Causes & Risk Factors
The condition often affects people born with disorders that can weaken the suspensory ligaments. For example, about six out of ten people with Marfan syndrome suffer dislocated lenses in their eyes. The second most significant cause of lens displacement is eye trauma, such as being hit by a blunt object. It can break some or all the connective tissues causing the lens to be wholly or partially detached.
Risk factors include eye injuries and crystalline pseudoexfoliation syndrome (PSX), a disorder involving the breakage of the suspensory ligament fibers.
Signs & Symptoms
Symptoms of lens dislocation vary depending on the severity of the condition. Usually, a partially detached lens doesn't display any symptoms. In other cases, the symptoms may include:
- Blurred vision
- A quivering iris
- Fluctuating vision
- Mild to severe nearsightedness
One should see a doctor if they experience blurry vision after an eye injury.
The ophthalmologist will analyze the symptoms and determine the complete patient's medical history. S/he will assess the history of trauma or underlying disease like Marfan syndrome. S/he will conduct a thorough eye examination, including the physical evaluation and slit-lamp eye examination.
In most cases, the doctor will only monitor the condition to make sure it remains stable. S/he may prescribe lenses to correct the blurry vision caused by the disorder. Where other eye injuries or disorders accompany the displacement, the doctor may recommend eye surgery. For example, a damaged lens may need to be removed and replaced with an artificial implant, i.e., intraocular lens (IOL) and a retinal tear may require repair.
Prognosis & Long-Term Outlook
The condition is usually permanent, and patients need glasses for a clear vision. In some cases, cataracts form over time, and the patient may need cataract surgery for better vision.
Prevention & Follow Up
The best preventive measure is using protective eye gear, especially when playing sports or doing hazardous work. Protective eyewear, such as eye shields or goggles, can help keep sticks, fists, balls, or other projectiles/objects from hitting the eye. People predisposed to the condition should be particularly cautious, although they can get the problem even without trauma.
Regular eye check-ups allow the doctor to monitor eye health and detect anomalies, including a dislocated lens.