[Functional aspects of intraocular lens replacement]

Advances in surgical techniques and intraocular lens (IOL) design have reduced the incidence of complications requiring lens removal and replacement. However, complications requiring IOL removal/replacement may still occur in clinical practice. In addition to the main indications for IOL replacement, such as incorrect IOL power calculation, IOL opacification, damage to the IOL haptics, IOL dislocation, decentration, or displacement, there are less common causes associated with disturbing light phenomena, optical aberrations, and low uncorrected visual acuity at preferred viewing distances. We observed 3 patients (4 eyes) who underwent IOL replacement due to disturbing light phenomena and low uncorrected visual acuity at preferred viewing distances. In the first clinical case, an Extended Depth-of-focus IOL was replaced with a trifocal IOL in both eyes. In the second case, a monofocal IOL was replaced with a trifocal IOL. In the third, a bifocal IOL was replaced with a trifocal IOL. All patients noted an improvement in visual acuity at their preferred viewing distances after IOL replacement, complaints of disturbing photic phenomena resolved. The trifocal IOL best met the patients' vision quality needs (in patients without severe corneal, retinal, or optic nerve pathology, and with preserved pupillary function) and ensured spectacle independence. In all three clinical cases, the original IOL was replaced with a trifocal IOL due to its ability to provide spectacle independence at different distances and maximum subjective satisfaction with vision quality. In patients dissatisfied with the refractive performance of monofocal or bifocal IOLs or experiencing disturbing optical phenomena, IOL replacement may be recommended in the absence of retinal pathology, provided that the capsular bag and lens ligaments are intact and the endothelial cell density is sufficient (>1000 cells/mm²).