Abstract:AIM: To evaluate the possible predisposing risk factors for late in-the-bag spontaneous IOL dislocations and to study the early surgical and visual outcomes of repositioning and exchange surgeries. METHODS: Medical and surgical records of 39 eyes of 39 patients who underwent IOL repositioning or exchange surgery for dislocation between 2010 and 2018 were reviewed. Possible predisposing risk factors and some characteristics of late in-the-bag spontaneous IOL dislocations; outcomes of IOL repositioning and exchange surgeries, including visual acuity, refractive status before and after surgery and postoperative complications were evaluated. RESULTS: The predisposing factors for late in-the-bag spontaneous IOL dislocations were pseudoexfoliation [PEX; 12/39 (30.8%)], previous vitreoretinal surgery [7/39 (17.9%)], axial myopia [3/39 (7.7%)], both PEX and axial myopia [1/39 (2.6%)], both previous vitreoretinal surgery and axial myopia [2/39 (5.1%)] and uveitis [1/39 (2.6%)]. The mean interval between cataract and dislocation surgery was 7.23y, greater in PEX positive group (8.63y). The mean best corrected visual acuity (BCVA) improved significantly after dislocation surgery (P<0.001) and also improved significantly after exchange surgery (P=0.001). The mean value of spherical equivalant decreased significantly after dislocation surgery (P=0.011), whereas corneal astigmatism increased but this difference was not significant after dislocation surgery and exchange surgery (P=0.191, P=0.074, respectively). CONCLUSION: The most prevelant risk factors for late in-the-bag spontaneous IOL dislocations are PEX, previous vitreoretinal surgery and axial myopia. In the management of IOL dislocations, exchange surgery with small corneal incision seemed effective with improved BCVA and safety with low postoperative complications.