Intraocular lens (IOL) Dislocation M.R. Akhlaghi MD
IOL dislocationIncidence • Intraocular lens (IOL) dislocation has been reported to occur in 0.2% to 1.8% of patients after cataract surgery
IOL dislocationCauses: Main cause is sub optimal posterior capsule supports during or early post operative
IOL dislocationCauses: During operation: • Unknowingly placement • Misjudging haptic placement • Misjudging capsule support At least 180 degree of a substantially broad rim of post. capsule at least half of which is in the interior quadrant is necessary for satisfactory PC IOL support.
IOL dislocationCauses: Days of weeks after surgery: • Spontaneously IOL haptic rotation • Zonolar dehiscent
IOL dislocationCauses: Months or years after surgery • Trauma • Spontaneously loss of zonolar support. (PEX), Marfan syn.
IOL dislocationEvaluation: • Degree of lens malposition • Accompanying complications • Symptoms
IOL dislocationEvaluation: Degree of lens malposition • Mild: the optic covering more than ½ pupilary space • Moderate: the optic covering less than ½ pupillary space • Subluxated: open pupillary space but in the anterior vitreous • Luxated: completely dislocation
IOL dislocationEvaluation: Symptom & signs is related to degree of malposition: • Glare : related to edge of the IOL optic • Induced astigmatism • Decreased VA • Monocular Diplopia • Floater like symptoms: in luxated & complete mobile IOL • Pupillary block glaucoma: in luxated & complete mobile • Retinal trauma (in luxated & complete mobile)
IOL dislocationEvaluation: Accompanying complications • Inflammation • increased IOP • Vitreous incarceration • Retinal damage • CME
IOL dislocation management: • The best approach must be determined individually and is based on factors such as clinical circumstances and coexisting complications • Methods (non surgical, surgical) • Time of surgery • Method of surgery
IOL dislocationmanagement: Non surgical management • Observation is usually recommended for IOLs with simple decentration • If aphakic contact lens correction is satisfactory, • If systemic or ocular problems prohibit further Surgery • If the patient simply elects not to pursue further surgery
IOL dislocationmanagement surgical management • Usually non surgical methods is not satisfactory or convenient to the most of patients
IOL dislocationSurgical management: Indications • decreased VA • persistent CME • Increased IOP and inflammation • coexisting RD • Retain lens material • monocular diplopia • halo phenomenon • fluctuating vision caused by shifting IOL
IOL dislocationTime of Surgical management Optimal time for intervention • intraoperative IOL dislocation: • IOL dislocation days after operation: • dislocations occurring distantly:
IOL dislocationsurgical management: • IOL removal • IOL exchange • IOL repositioning • Secondary IOL
IOL dislocationsurgical management: Surgical approach • Limbal incision: in moderate decentration or subluxated if post. capsule is largely intact • Pars plana vitrectomy: In luxated IOL offer optimal control to achieve the goal of surgery in subluxated IOL specially if posterior migration occurs
IOL dislocationsurgical management: IOL removal • RD • Inflammation • Trauma • IOL removal with or without exchangeis usually performed for IOLs with damaged haptics, small optics, or highly flexible haptics unsuitable for suture support
IOL dislocationsurgical management: IOL exchange • Risk of endothelial cell trauma • Explantation & reimplantation may risk more corneal endothelial trauma compared with repositioning • Exchange for an AC.IOL causes less trauma to endothelial compared with PC IOL placement
IOL dislocationsurgical managment: IOL Repositioninig • Most common elected approach • Three basic approaches • In the residual bag or sulcus • iris suture fixation • Scleral fixation Repositioning a PC IOL in AC may induce chronic iritis, inflammation, and corneal decompensation.
IOL dislocationsurgical managment Secondary IOL: • (AC,PC) without explanation of dislocation IOL only in unusual circumstances
IOL dislocation Outcomes & complications Final outcomes depends on • preoperative macular function • Post operative complication of original cataract surgery (CME & RD) • Complication of final operation
IOL dislocation Outcomes & complications In some studies • VA > 20/40 50-94% • Initial coexisting RD 0-10% • combined rate of RD 0-16%
IOL dislocation Recommendation • Anterior vitrectomy (avoid vitreous incarceration) • A second IOL should not be placed • Frequent topical steroids • If indicated IOP-reducing agent • Vitreoretinal refferal • Careful attention to detect other complications