CONTRIBUTION FACTORS OF EFFECTIVE LENS POSITION, TILT, AND DECENTRATION DURING FLANGED SCLERAL FIXATION OF INTRAOCULAR LENS

Purpose: The authors aimed to elucidate the factors related to effective lens position, tilt, and decentration of scleral fixed intraocular lenses (IOLs) with a flanged haptic technique in an artificial eye model using anterior segment optical coherence tomography. Methods: Two bent 27-gauge needles were passed through a 1.0- or 2.0-mm scleral tunnel, 2.0 mm posterior to the limbus and 180 degrees apart. Both haptics of a three-piece IOL were docked with guide needles and externalized. Factors related to the IOL position were analyzed using anterior segment optical coherence tomography and a stereomicroscope. Results: The 1.0-mm scleral tunnel induced a significantly longer effective lens position than the 2.0-mm tunnel and suture fixation (P < 0.05 and P < 0.01, respectively). Discrepancy in scleral tunnel length induced higher decentration of the optic to the opposite side of the haptic-embedded shorter tunnel and tilt perpendicular to the fixed axis than that in the scleral tunnel of the same length (P < 0.001 and P < 0.05, respectively). If the scleral fixation points of both haptics are not exactly 180 degrees apart, the IOL may become decentered and tilted (P < 0.01 and P < 0.05, respectively). Conclusion: In the flanged haptic technique, the length, balance, and position of both scleral tunnels determine IOL effective lens position, tilt, and decentration.