![]() IOL dislocation may present as phacodonesis, simple lens decentration within an intact capsular bag or in the sulcus, partial lens subluxation out of the capsular bag, or complete dislocation of the lens within or outside of the bag into the anterior or posterior chamber. If a detailed exam is not feasible, Bscan echography and/or an anterior segment OCT/ ultrasound biomicroscopy (UBM) may be helpful in evaluating a posteriorly dislocated lens behind the iris in the anterior aspect of the vitreous cavity. A detailed dilated retinal exam with scleral depression is important. Some patients also report seeing the edge of the IOL.Ī complete ophthalmologic exam is necessary in diagnosis of a dislocated IOL including an anterior and posterior segment exam. ![]() ![]() Additionally, they may report ocular pain or headaches from intermittent angle-closure and/or inflammation. Patients with a dislocated IOL may experience a decrease or change in vision, diplopia, and/or glare. Given that there are many predisposing conditions that increase the risk of IOL dislocation, a thorough history is necessary in patients. The impact of neodymium:YAG (Nd:YAG) laser for treatment of PCO may be the trigger point for subluxation. Increased epithelial cell proliferation seen in posterior capsular opacification (PCO) may contribute to the IOL and capsular bag weight, which leads to increased zonular stress. In patients with weaker zonules, as seen in pseudoexfoliation syndrome, retinitis pigmentosa, and diabetes mellitus, the constriction that occurs is more pronounced. This centripetal force overcomes the centrifugal zonal force and leads to constriction of the capsulotomy. Trauma caused by capsulotomy of the anterior capsule leads to proliferation and metaplasia of the lens epithelial cells on the capsular margins into myofibroblasts, which subsequently creates a contraction force. Ĭapsular opening contraction is commonly observed after cataract surgery and can be accompanied by continuous curvilinear capsulorrhexis. repeated eye rubbing), previous acute angle-closure attacks, and connective tissue disorders. Progressive zonular weakness has been associated with previous vitreoretinal surgery, uveitis, trauma, high myopia, retinitis pigmentosa, aging, diabetes mellitus, atopic dermatitis (e.g. Late dislocation of the lens typically occurs due to progressive zonular insufficiency and contraction of the anterior capsule. Zonular rupture usually occurs from posterior pressure on the lens and the capsule while performing "can-opener style" capsulotomy, phacoemulsification of the nucleus, or IOL implantation. ![]() Early dislocation of the lens may occur with poor fixation of the IOL or capsular and/or zonular rupture during cataract surgery. With relation to cataract surgery, IOL dislocation may be categorized based on the timing of its presentation – early if it occurs within three months of IOL placement, and late if it occurs three months after IOL placement. pseudoexfoliation syndrome (being the most common risk factor with more than 50% of cases), Marfan syndrome, homocystinuria, hyperlysinemia, Ehlers-Danlos Syndrome, scleroderma, Weill-Marchesani syndrome, ectopia lentis et pupillae. There are many predisposing conditions that increase the risk of capsular bag instability and zonular weakness including cataract surgery, prior vitreoretinal surgery, aging, axial myopia, inflammation/uveitis, trauma, retinitis pigmentosa, diabetes mellitus, atopic dermatitis, mature cataract, previous episodes of acute angle-closure attack, connective tissue disorders e.g. IOL dislocation is typically related to the integrity of the capsular bag and its support system (zonules) and their ability to support an IOL. ![]() Once the dislocated IOL is identified, there are several possible management options. However, the terms are commonly interchanged. Dislocation is due to total zonular or capsular instability. Subluxation refers to partial zonular or capsular instability. Decentration usually refers to loss of IOL centration without zonular or capsular instability. Dislocation may present as phacodonesis, simple decentration within the bag or in the sulcus, partial subluxation, or complete dislocation of the lens within and outside of the bag. It may occur as a result of an early or late complication of cataract surgery, prior vitreoretinal surgery, trauma, or an inherent pathological process or connective tissue disorder contributing to lens zonular weakness. IOL dislocation has been reported at a rate of 0.2% to 3%. 3.3.4 Anterior Chamber Intraocular Lens (ACIOL) placementĭislocated intraocular lens (IOL) is a rare, yet serious complication whereby the intraocular lens moves out of its normal position in the eye. ![]()
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