Clinical outcomes of new multifocal intraocular lenses with hydroxyethyl methacrylate and comparative results of contrast sensitivity, objective scatter, and subjective photic phenomena.

BACKGROUND: We investigate the performance of new hydrophobic diffractive multifocal intraocular lenses (IOL) with hydroxyethyl methacrylate (HEMA) and compare their optical quality, contrast sensitivity, and subjective photic phenomena. METHODS: Medical records of patients who underwent routine simple cataract surgery and insertion of an existing multifocal IOL (TFNT, TF group) or a new multifocal IOL (CNWT, CN group) were retrospectively reviewed. Clinical data was collected 2 months postoperatively and included optical quality analysis system (OQAS) indices, contrast sensitivity, and subjective degrees of photic phenomena. RESULTS: One hundred thirty-five eyes of 135 patients were included (CN group, 71; TF group, 64). There was no significant difference between the two groups in the visual acuity and defocus curve. The indices of OQAS did not show a significant difference between groups. Contrast sensitivity was significantly better in the CN group at all degrees, including the area under the log contrast sensitivity function (p = 0.01). The subjective photic phenomena survey showed better results for the CN group, with the proportion of patients reporting no photic phenomena as 9.9% and 3.1% in the CN and TF groups, respectively. The proportion of patients who reported severe photic phenomena was 11.3% in the CN group and 25.0% in the TF group. Although the follow-up period was only 2 months, glistening, surface scattering, and posterior capsule opacity were not observed in any patient. CONCLUSIONS: The new multifocal IOL with HEMA is safe, and provides stable visual acuity as well as superior contrast sensitivity and lower subjective photic phenomena, over the prior IOL.

Vertical implantable collamer lens as a novel method to increase rotational stability.

PURPOSE: We investigated the vertical implantation of a toric implantable collamer lens (ICL) and compared the rotational stability with that of horizontal implantation. METHODS: This matched comparative study retrospectively reviewed and analyzed data from patients who underwent ICL implantation from 2003-2022 by 1:1 matching vertical and horizontal (V and H toric groups, respectively) implantation patients according to preoperative astigmatism, spherical equivalent, sulcus-to-sulcus, anterior chamber depth, and ICL size. Visual acuity, manifest refraction, vaulting, and rotation were measured 3 months postoperatively. RESULTS: We included 646 eyes (323 each in the V and H toric groups). No statistically significant difference was observed between groups in postoperative visual acuity, refractive error, and astigmatism. Vaulting was lower in the V toric group. (P < 0.001). The mean lens rotation in the V toric group was less than that in the H toric group (1.11 ± 2.84° versus 3.02 ± 10.34°, P = 0.001). The proportion of eyes in the V and H toric groups showing ≥10° of rotation was 2.5% (8 eyes) and 6.5% (21 eyes), respectively (P = 0.014). Despite repositioning from rotation, three (0.9%) and eight (2.5%) eyes required removal owing to lens re-rotation in the V and H toric groups, respectively. CONCLUSION: Toric ICL vertical implantation showed good rotational stability, and appropriate visual acuity correction results with relatively low vaulting. This procedure therefore presents an effective novel method that could replace horizontal toric ICL implantation.