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Purpose: To evaluate the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy on intraocular lens (IOL) position and anterior segment parameters with a new swept-source anterior segment optical coherence tomography (AS-OCT) device (Anterion ® , Heidelberg Engineering GmbH)., Patients and Methods: A total of 50 eyes from 50 consecutive patients were included. All patients had visually significant posterior capsular opacification (PCO) after uneventful phacoemulsification surgery with manual capsulorhexis and single-piece C-loop acrylic IOL implantation (AcrySof ® SA60AT) and were treated with Nd:YAG laser. Anterior segment images were captured with Anterion ® in non-dilated conditions before and one month after the procedure. In the "Metrics App", we collected data of the anterior chamber angle (ACA) 3 and 9 o'clock, the anterior chamber depth (ACD), the anterior chamber volume (ACV), and the central corneal thickness (CCT). We also collected demographic and clinical data [age, gender, months from surgery to Nd: YAG capsulotomy, pre- and post-capsulotomy corrected distance visual acuity (CDVA) and spherical equivalent, and axial length]., Results: We did not find a statistically significant difference in ACD after the Nd:YAG capsulotomy (3.96 ± 0.55 vs 3.97 ± 0.55 mm, p = 0.10). In 28 patients, we noted a backward movement of the IOL; in the remaining 22, the IOL moved forward or did not change at all. We did not observe significant changes in ACA at the 3 and 9 o'clock reference points, ACV, or CCT. There was an improvement in CDVA after the procedure (0.37 ± 0.21 vs 0.12 ± 0.27 logMAR, p = 0.015), without statistically significant differences in SE (-0.15 ± 0.84 vs -0.25 ± 0,93, p = 0.42). Axial length was not correlated with ACD variations after the procedure (p = 0.67)., Conclusion: Our results show that Nd:YAG laser capsulotomy does not change the axial position of a single-piece C-loop acrylic IOL inside the capsular bag, as well as other anterior chamber parameters., Competing Interests: The authors report no conflicts of interest in this work., (© 2022 João et al.)

Purpose: To evaluate and compare the changes in refraction and effective intraocular lens (IOL) position between a plate-haptic IOL and a c-loop single-piece IOL after neodymium-doped yttrium aluminium garnet (YAG) laser posterior capsulotomy., Methods: In a prospective study, anterior chamber depth and subjective refraction were measured in 110 pseudophakic eyes from 110 patients, before and 1 month after YAG laser capsulotomy. Patients were divided into 2 groups according to the IOL design: group 1 (plate-haptic acrylic hydrophilic AT LISA tri 839MP ® ) and group 2 (c-loop acrylic hydrophobic single-piece AcrySof ® SA60AT). Lens position was obtained through optical coherence biometry (Biograph WaveLight OB820 ® )., Results: YAG laser capsulotomy was performed 37.8±9.8 months after surgery in group 1 and 40.6±8.6 months in group 2 ( p =0.125). Significant changes were found in the lens effective position after treatment in the 2 groups. The YAG posterior capsulotomy led to a change of anterior chamber depth in group 1 from 4.03±0.32 mm to 3.86±0.34 mm ( p =0.02) and in group 2 from 4.03±0.37 mm to 4.14±0.45 mm ( p =0.025). After YAG laser posterior capsulotomy, no significant changes were observed in mean spherical equivalent, sphere or cylinder for both groups ( p >0.05)., Conclusion: YAG laser posterior capsulotomy can induce a significant change in the IOL position according to the IOL type; however, the refractive change after treatment is clinically insignificant., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Purpose: To evaluate the correlations between preoperative Scheimpflug-based lens densitometry metrics and phacodynamics., Methods: The Lens Opacities Classification System III (LOCS III) was used to grade nuclear opalescence (NO), along with different methods of lens densitometry evaluation (absolute scale from 0% to 100%): three-dimensional (3D), linear, and region of interest (ROI) modes. Cumulative dissipated energy (CDE) and total ultrasound (US) time were recorded and correlated with the different methods of cataract grading. Significant correlations were evaluated using Pearson or Spearman correlation coefficients according to data normality., Results: A positive correlation was detected between the NO score and the average density and the maximum density derived from the 3D mode (r=0.624, P<0.001; r=0.619, P<0.001, respectively) and the ROI mode (r=0.600, P<0.001; r=0.642, P<0.001, respectively). Regarding the linear mode, only the average density parameter presented a significant relationship with the NO score (r=0.569, P<0.001). The 3D-derived average density and maximum density were positively correlated with CDE (rho =0.682, P<0.001; rho =0.683, P<0.001, respectively) and total US time (rho =0.631 and rho =0.668, respectively). There was a linear relationship between the average density and maximum density of the ROI mode and CDE (rho =0.686, P<0.001; rho =0.598, P<0.001, respectively) and total US time (rho =0.642 and rho =0.644, respectively). The average density was the only parameter derived from the linear mode that showed a significant correlation with CDE (rho =0.522, P<0.001) and total US time (rho =0.450, P<0.001)., Conclusion: Specific Scheimpflug-derived densitometric parameters of the nucleus correlated with phacoemulsification parameters. The use of the appropriate densitometry approach can predict more efficiently the phacodynamics.