Visual and refractive outcomes of trocar-assisted intrascleral three-piece intraocular lens fixation

Purpose To report the visual and refractive outcomes of trocar-assisted sutureless intrascleral three-piece intraocular lens (IOL) fixation, and to compare the accuracy of different IOL power formulas in this setting. Methods Twenty eyes of 20 patients who underwent trocar-assisted sutureless three-piece IOL scleral fixation were included. Two trocar-cannula systems were placed at 3 and 9 o'clock position creating 2.5 mm scleral tunnels. The haptics of a three-piece IOL were grasped with serrated retinal forceps, externalized through the scleral tunnels and fixed by making a flange. Prediction error (PE) was calculated as the actual postoperative spherical equivalent (SE) refraction minus the SE predicted refraction. The predicted SE was calculated using the Barret Universal II, Emmetropia Verifying Optical (EVO), Hoffer Q, Holladay 1, Holladay II, and SRK/T. Results At 6 months after surgery, corrected distance visual acuity improved from 0.66 +/- 0.36 to 0.17 +/- 0.13 logMAR (p < .001). The lowest median absolute PE was obtained by the Barrett formula (0.73D), followed by the EVO (0.81D), Holladay 1 (0.94D), SRK/T (0.98D), Hoffer Q (1.05D) and Haigis (1.64D) formulas. The highest percentage of eyes within +/- 1.00 D were obtained with the Barrett (60.0%), and EVO (55.0%) formulas. Conclusion Although trocar-assisted intrascleral three-piece IOL fixation yields good visual results, the predictability of refractive outcomes is lower than in standard cataract surgery. All formulas showed a slight tendency towards a hyperopic refractive surprise.