Astigmatism and Refractive Outcome After Late In-The-Bag Intraocular Lens Dislocation Surgery: A Randomized Clinical Trial.

Purpose: To compare surgically induced astigmatism (SIA) and refractive outcomes between two operation methods for late in-the-bag IOL dislocation.

Methods: In this prospective, randomized, parallel-group clinical trial, 104 patients (eyes) were assigned to IOL repositioning by scleral suturing 1.5- to 2-mm posterior to limbus (n = 54) or IOL exchange with a retropupillar iris-claw IOL using a 5.5-mm scleral pocket incision (n = 50). The SIA was determined by vector analysis through conversion of corneal cylinders to Cartesian coordinates, and is presented as magnitude in diopters @ direction in degrees (D @ °). Follow-up was 6 months.

Results: The SIA was 0.24 D @ 8° for IOL repositioning and 0.65 D @ 171° for IOL exchange, which was a nonsignificant group difference (X coordinate: P = 0.08; Y coordinate: P = 0.16). Mean SIA magnitude was 0.60 ± 0.50 D and 1.12 ± 0.85 D, respectively (P < 0.001). Mean postoperative spherical equivalent was -1.6 ± 1.6 D after IOL repositioning and -0.5 ± 1.0 D after IOL exchange (P < 0.001). For IOL repositioning, this represented a mean myopic shift of -0.7 ± 1.1 D compared with before the IOL dislocation (P < 0.001). For IOL exchange, it was within ±1 D of target refraction in 83% of the patients.

Conclusions: Surgically induced astigmatism was modest in both operation groups, albeit with a tendency of being more pronounced for IOL exchange. Repositioning surgery led to a myopic shift, whereas exchange surgery provided good refractive predictability.