Intraocular lens (IOL) Dislocation M.R. Akhlaghi MD

IOL dislocation Incidence Intraocular lens (IOL) dislocation has been reported to occur in 0.2% to 1.8% of patients after cataract surgery

IOL dislocation Causes: Main cause is sub optimal posterior capsule supports during or early post operative

IOL dislocation Causes: 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 dislocation Causes: Days of weeks after surgery: Spontaneously IOL haptic rotation Zonolar dehiscent

IOL dislocation Causes: Months or years after surgery Trauma Spontaneously loss of zonolar support. (PEX), Marfan syn.

IOL dislocation Evaluation: Degree of lens malposition Accompanying complications Symptoms

IOL dislocation Evaluation: 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 dislocation Evaluation: 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 dislocation Evaluation: 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 dislocation management: 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 dislocation management surgical management Usually non surgical methods is not satisfactory or convenient to the most of patients

IOL dislocation Surgical 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 dislocation Time of Surgical management Optimal time for intervention intraoperative IOL dislocation: IOL dislocation days after operation: dislocations occurring distantly:

IOL dislocation surgical management: IOL removal IOL exchange IOL repositioning Secondary IOL

IOL dislocation surgical 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 dislocation surgical management: IOL removal RD Inflammation Trauma IOL removal with or without exchange is usually performed for IOLs with damaged haptics, small optics, or highly flexible haptics unsuitable for suture support

IOL dislocation surgical 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 dislocation surgical 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 dislocation surgical 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