Comparative Evaluation of the Defocus Curve of Monofocal IOL, Extended Depth of Focus IOL, and Trifocal IOL

Abstract

Purpose. Comparative evaluation of the defocus curve (DC) of monofocal IOLs (MIOLs), extended depth of focus IOLs (EDОF) and trifocal IOLs (TIOLs). Patients and methods. We observed 90 patients (average age 57.8 ± 1.8 years) who underwent standard binocular phacoemulsification of cataracts in both eyes with emmetropic “target” refraction and postoperative monocular uncorrected distance visual acuity (UCVA) of at least 1.0 rel. units. All patients were divided into three groups equal in number of patients, age, gender and visual status, corresponding to three options of implantable IOLs: MIOL (“RayOne Aspheric”, model RAO600C); EDOF (RayOne EMV, model RAO200E) and THYOL (RayOne Trifocal). DC was performed binocularly based on a standard BCVA measurement with an optical load for defocusing from +3.0 D to -4.0 D with a “step” of +1.0 D and -0.5 D. Results. Under conditions of optical defocusing with positive lenses (1.0; 2.0; 3.0 D), all three types of IOLs maintained almost the same average BCVA (at +1.0 D, the BCVA range was 0.72–0.76 rel. units; at +2.0 diopters — 0.66–0.72 relative units; at +3.0 diopters — 0.52–0.56 relative units). In relation to the analysis of BCVA in conditions of defocusing with negative lenses, it was found that visual acuity was significantly better with EDOF than with MIOL, with a load from -1.0 to -4.0 diopters, while these differences were statistically significant and ranged from 0.14 to 0.27 relative units (p < 0.01). Along with this, it was determined that UCVA was significantly better in the group with TIOL than in the group with EDOF, with a load from -2.5 to -4.0 D. Moreover, these differences were statistically significant and ranged from 0.09 to 0.14 rel. units (p < 0.01). Conclusion. The design features of IOLs make it possible to consider implantation of EDOF as an option for an individual approach to the selection of IOLs, especially taking into account the possibility of use in patients whose professional activities involve long-term visual work at intermediate distances (for example, users of personal computers).