Influence of intraocular lens subsurface nanoglistenings on functional visual acuity

Abstract

To investigate the influence of intraocular lens subsurface nanoglistenings (SSNGs) on functional visual acuity (FVA), thirty-nine eyes of 29 patients were examined in this study. The SSNG group comprised 19 eyes of 14 patients (75.7± 5.4 years, mean ± standard deviation), and the control group comprised 20 eyes of 15 patients (73.6 ± 6.5 years). The SSNGs were diagnosed on the basis of the typical whitish IOL appearance upon slit-lamp examination and results of densitometry regarding surface light scattering using Scheimpflug images. The FVA measurement system (AS-28; Kowa, Aichi, Japan) was used to examine changes in continuous visual acuity (VA) over time, and visual function parameters such as FVA, visual maintenance ratio (VMR), maximum VA, minimum VA, standard deviation of VA, and number of blinks were assessed. The results were compared between the SSNG and control groups, and correlations of FVA parameters with the intensity of surface light scattering, time after surgery, and age were also evaluated. There were significant differences in VMR (P = 0.035) and standard deviation of VAs (P = 0.031) between the two groups, although no significant differences were found in baseline VA, FVA, maximum VA, minimum VA, and number of blinks. None of the FVA parameters showed any significant correlations with the intensity of surface light scattering, time after surgery, or age. There is a possibility that VA is unstable during a continuous gazing task in patients with SSNGs.

Influence of implantations of extended depth-of-focus on standard automated perimetry

“…However, there could be further slight changes in visual function, which may not be detected with the conventional contrast sensitivity test. Such slight changes could be evaluated using a contrast visual acuity chart or functional visual acuity test 16 . Last, the ages of the three groups were different.…”

The assessment of the impact of glistening on visual performance in relation to tear film quality

“…In some cases glistening caused higher loss variance [ 26 ] or higher mean deviation [ 24 ] in the visual field, or impaired fundus visualization [ 27 ]. Examining differences in functional visual acuity, Hiraoka et al (2017) found that the visual maintenance ratio decreased, while the standard deviation of visual acuity increased in eyes with IOL subsurface nanoglistening [ 28 ]. Summarizing the data above, it seems that in most of the recent studies with sophisticated examination methods glistening was associated with some effect on visual function, although it was often only a moderate one.…”

Quantitative Multiparameter Evaluation of Vacuoles in Intraocular Lenses Employing a High-Magnification Digital Microscopy Method

“…However, some newer designs and materials used in IOLs have an increased tendency to form small, micrometer-sized, fluid-filled vacuoles within the bulk of the IOL [3–18]. These vacuoles, also commonly referred to as glistenings, have been shown to reduce contrast sensitivity (CS) and visual acuity (VA) [13, 14, 17, 19–21], in some cases requiring IOL explantation [17, 21].…”

“…The grading scales generally range from grade 0, having no or trace vacuoles, to the highest grade, usually either 3 or 4, having extremely severe vacuoles. Various test methods have been employed to measure the clinical and nonclinical effects of vacuoles and light scatter in general, including subjective patient reports and VA tests [7, 10, 11, 13, 14, 16, 17, 19–21], integrating spheres and transmission measurements [16, 21, 24–26], C-Quant straylight meter measurements [18, 20, 27–29], and in vivo slit-lamp and Scheimpflug tests and measurements [7, 10, 11, 13–17, 19–21, 23]. In addition, two different methods have been independently developed to physically scan around the back of the IOL to measure forward scattered light [26, 27, 30, 31].…”