IOLdislokation

IOL dislokation refers to the displacement of an implanted intraocular lens from its intended position after cataract or other intraocular lens surgery. The condition is often described as subluxation when the lens is only partially displaced, and luxation when it is completely displaced. Dislocation can occur into the anterior chamber or into the vitreous cavity, with potential to cause vision loss or eye complications.

Causes and risk factors include weakness or rupture of the zonular fibers that hold the capsular bag, often due to conditions such as pseudoexfoliation syndrome, Marfan or homocystinuria, high myopia, previous trauma, or prior ocular surgery. Age-related capsule weakness, inflammation, or trauma-related damage can also contribute. IOL designs and surgical techniques that rely on compromised capsule support increase risk in some patients.

Clinical presentation ranges from mild to severe. Patients may notice decreased vision, monocular diplopia, or glare. An anterior chamber dislocation can cause corneal edema, shallowing of the anterior chamber, iridocorneal angle closure, and secondary glaucoma. Posterior dislocation may be asymptomatic or lead to retinal detachment, cystoid macular edema, or uveitis. Diagnosis is based on slit-lamp examination with a dilated pupil; imaging tools such as ultrasound biomicroscopy, anterior segment optical coherence tomography, or B-scan ultrasound may be used when media are cloudy.

Management depends on location, extent, symptoms, and comorbidities. Asymptomatic mild subluxation may be observed with corrected vision. Symptomatic or visually significant cases often require surgical intervention, such as repositioning or removing the IOL and implanting a scleral-fixed or iris-claw IOL, or performing pars plana vitrectomy with IOL exchange. Urgent removal or repositioning is indicated for anterior dislocations to prevent corneal damage or glaucoma, while posterior dislocations may be managed with vitrectomy and IOL realignment or exchange.

Prognosis varies; timely, appropriate treatment improves outcomes, but complications like glaucoma or retinal detachment can affect visual prognosis. Prevention focuses on identifying high-risk eyes, careful surgical technique, and the use of supplementary capsule-support devices when indicated.