How Does A Lens Dislocate?
There are two mechanisms for a lens implant to dislocate into the back of the eye. The first occurs where a break in the capsular bag that holds the lens causes the lens to slip back. The second cause happens if the cables that attach the lens to the eye wall break, allowing the entire lens-bag complex to fall into the back.
What Are the Risk Factors for A Shifted Intraocular Lens?
There are two main categories of dislocated lens implant. The first occurs during your initial cataract surgery and is caused by a break in the layer that holds the lens or the cables that attach it to the eye. Anything that weakens the lens capsule, or its cables may cause a dislocation during surgery. This includes history of previous eye surgery, trauma, or use of prostate medication. Some patients have a condition called pseudo exfoliation, which weakens the cables (zonules) that connect the lens to the eye wall.
The second mechanism for lens dislocation is the gradual breakage over time of the cables that attach the lens implant to the eye wall. Eventually, enough cables break to allow the lens to shift away from the center of the pupil. This happens more often in patients with a history of trauma, multiple eye surgeries (especially retinal detachment repair), pseudo exfoliation, and complicated original cataract surgeries.
What Are the Symptoms of a Dislocated Lens?
The most common symptom of a dislocated intraocular lens implant is sudden, painless blurring of vision in one eye. The vision tends to be very blurry, but not blacked-out. Sometimes, the lens implant can be seen resting on the surface of the retina when laying on the back. If the lens is only slightly out of position, the patient may only notice a ghost or double image at nighttime as some light passes through the pupil around the edge of the lens.
How Is A Dislocated Lens Diagnosed?
Anyone who believes that their lens implant is dislocated should seek a dilated examination with an ophthalmologist. The eye doctor will check your vision, dilate your pupils, and confirm the position of the lens. If a dislocation is found, it is important to assess the rest of the eye to ensure there are no other concerns prior to surgical repair.