IOLs glistenings and quality of vision

Comparative study of the glistening between four intraocular lens models assessed by OCT and deep learning

PURPOSE

To evaluate the glistening in 4 different models of intraocular lenses (IOLs) using optical coherence tomography (OCT) and deep learning (DL).

SETTING

Centro Internacional de Oftalmología Avanzada (Madrid, Spain).

DESIGN

Cross-sectional study.

METHODS

325 eyes were assessed for the presence and severity of glistening in 4 IOL models: ReSTOR+3 SN6AD1 (n = 41), SN60WF (n = 110), PanOptix TFNT (n = 128) and Vivity DFT015 (n = 46). The presence of glistening was analyzed using OCT, identifying the presence of hyperreflective foci (HRF) in the central area of the IOL. A manual and an original DL-based quantification algorithm designed for this purpose was applied.

RESULTS

Glistening was detected in 22 (53.7%) ReSTOR SN6AD1, 44 (40%) SN60WF, 49 (38.3%) PanOptix TFNT, and 4 (8.7%) Vivity DFT015 IOLs, when any grade was considered. In the comparison of the different types of IOLs, global glistening measured as total HRF was 17.3 ± 25.9 for the ReSTOR+3; 9.3 ± 15.7 for the SN60WF; 6.9 ± 10.5 for the PanOptix; and 1.2 ± 2.6 for the Vivity ( P < .05). There was excellent agreement between manual and DL-based quantification (≥0.829).

CONCLUSIONS

It is possible to quantify, classify and compare the glistening severity in different IOL models using OCT images in a simple and objective manner with a DL algorithm. In the comparative study, the Vivity presented the lowest severity of glistening.

Glistening on intraocular lenses: A review

The glistening in intraocular lenses (IOLs) is a phenomenon in which tiny water-filled microvacuoles (MVs) form within the IOL material, causing light to scatter and create a sparkling or shimmering effect. The presence of glistening is common in many types of IOL materials and models and has been extensively studied in recent years to determine its incidence, risk factors, evolution, and possible clinical relevance. Classically, it has been studied in vitro in the laboratory or by means of photography obtained with a slit lamp, but these were techniques that required either specific technology or an expert explorer, complex image processing, and required a lot of time. In recent years, proposals based on the Scheimpflug camera and optical coherence tomography have emerged to try to simplify the analysis of glistening in IOLs. It has been described that the manufacturing process, the hydrophobic acrylic material, or the time since surgery are risk factors for the appearance of glistening. In addition, many issues related to this phenomenon are still unknown, such as not knowing from what number of points or their size they may have relevance to visual function since different optical phenomena related to glistening have been described on the IOLs.

Comparison of 3-month visual outcomes of a new multifocal intraocular lens vs a trifocal intraocular lens

PURPOSE

To compare the clinical performance of the TECNIS Synergy multifocal (model ZFR00V) intraocular lens (IOL) with that of the AcrySof PanOptix Trifocal (model TFNT00) IOL in patients undergoing bilateral cataract surgery.

SETTING

Multicenter clinical setting.

DESIGN

Prospective randomized comparative study.

METHODS

Patients aged 22 years or older were randomly assigned (2:1) to bilateral implantation with ZFR00V or TFNT00 IOLs. End points included the mean binocular distance-corrected near visual acuity (DCNVA) at 40 cm, photopic and mesopic DCNVAs at 33 cm, photopic low-contrast corrected distance visual acuity (CDVA) and mesopic CDVA, nondirected patient responses to an ocular/visual symptoms questionnaire, and safety.

RESULTS

Of the 150 patients implanted with IOLs, 95 of the 97 patients with ZFR00V IOLs and 52 of the 53 patients with TFNT00 IOLs completed the 3-month follow-up. Most patients in the ZFR00V and TFNT00 groups achieved 20/25 or better binocular CDVA (100% vs 96.2%) and DCNVA measured at 40 cm (88.4% vs 75.0%) and 33 cm (78.9% vs 51.9%). The mean between-group difference in binocular DCNVA at 40 cm favored ZFR00V IOLs (0.5 lines Snellen; 95% CI, 0.012 to 0.089; P ≤ .05). Similarly, the mean binocular photopic and mesopic DCNVAs at 33 cm (0.8 lines Snellen each; both P ≤ .05 vs TFNT00) and photopic high-contrast and low-contrast CDVA (0.5 lines Snellen each; both P ≤ .05 vs TFNT00) favored ZFR00V IOLs. Patient-reported ocular/visual symptoms and safety were generally similar between the 2 IOLs.

CONCLUSIONS

The ZFR00V IOL showed an extensive range of vision, particularly through near distances, and better mesopic performance than the TFNT00 IOL in patients undergoing cataract surgery.

Should We Abandon Hydrophilic Intraocular Lenses?

PURPOSE

To characterize the features of hydrophilic intraocular lenses (IOLs) important in the clinical context of expected prolonged duration time of the IOL within the eye.

DESIGN

Perspective.

METHODS

Discussion includes possible factors and mechanisms associated with hydrophilic IOLs' susceptibility to calcification and posterior capsule opacification (PCO) formation.

RESULTS

Results of recently reported studies show that particular surgeries, such as pars plana vitrectomy, Descemet stripping (automated) endothelial keratoplasty, and Descemet membrane endothelial keratoplasty with intraocular gas or air injection, might predispose the calcification process of hydrophilic IOLs, leading to a significant decrease in visual quality and possibly explantation of the IOL. Hydrophilic IOLs are more susceptible than hydrophobic IOLs to PCO formation, which is the most common of late postoperative complications that are associated with significant side effects.

CONCLUSIONS

We believe that all patients should be informed about the higher risk of calcification and PCO associated with hydrophilic IOLs. We also recommend limiting the use of hydrophilic acrylic IOLs during cataract surgery, especially when it is combined with pars plana vitrectomy or endothelial keratoplasty, and in patients with endothelial diseases who will probably require operation on it in the future.

Microscopic Characteristics of Late Intraocular Lens Opacifications

CONTEXT.—

The increases in overall life expectancy and in lens surgeries performed on younger patients have resulted in a significant increase in the anticipated duration of artificial intraocular lenses (IOLs) in the eye. Thus, the physicochemical properties of the IOL become a critical issue, and several types of postoperative IOL opacifications have been reported.

OBJECTIVE.—

To describe the microscopic characteristics of opacified IOLs. Glistenings and subsurface nanoglistenings are fluid-related phenomena developing mainly in hydrophobic acrylic IOLs and are associated with aqueous influx into the IOL matrix. Calcification presents in hydrophilic acrylic or silicone IOLs as deposits of hydroxyapatite or other phases of calcium. Snowflake degeneration is less common, and it manifests in older polymethyl methacrylate IOLs.

DATA SOURCES.—

PubMed and ScienceDirect databases were searched for the following keywords: intraocular lens, IOL, cataract surgery, phacoemulsification, opacification, glistening, subsurface nanoglistenings, calcification, snowflake degeneration. English-language articles published up to October 15, 2019 were included in the study. The manuscript contains mainly a literature review; however, it was supplemented with original investigations from the David J. Apple International Laboratory for Ocular Pathology.

CONCLUSIONS.—

Glistenings and subsurface nanoglistenings should be evaluated in a hydrated state and at room temperature; they manifest as microvacuoles sized from 1.0 to greater than 25.0 μm and less than 200 nm, respectively. Calcification deposits are situated on or underneath the surface of the IOL and can be stained with a 1% alizarin red solution or with the von Kossa method. Snowflake degeneration manifests as "particles" or "crystals," causing whitish IOL discoloration. Scanning electron microscopy or energy dispersive X-ray spectroscopy may improve the diagnostic accuracy.

A review of late intraocular lens opacifications

PURPOSE OF REVIEW

Phacoemulsification cataract surgery is one of the most commonly performed surgical procedure worldwide. In the majority of cases, intraocular lenses (IOLs) are implanted. Due to the increasing life expectancy and the fact that cataract surgery is performed in earlier stages, the anticipated IOL duration in the eye has increased over the last decades. The aim of this study was to review the types and describe the characteristics of late intraocular lens opacifications.

RECENT FINDINGS

Calcification was the most commonly reported type of opacification in hydrophilic IOLs; it usually negatively impacted the visual function and required IOL explantation. Glistening manifested in hydrophobic acrylic lenses and was frequent in some IOL models. In most cases glistening and subsurface nanoglistenigs do not lead to a decline in visual acuity or require IOL exchange. Current studies indicate that fluid-related phenomena may induce straylight, leading to a decrease of comfort and quality of vision.

SUMMARY

Several reports on late IOL opacifications have been published in recent years. In some cases, particularly in glistening, the development of the opacifications might be related to IOL aging. The influence of the fluid-related microvacuoles on the quality of vision requires further research.

A narrative review of intraocular lens opacifications: update 2020

The opacifications of intraocular lenses (IOLs) can significantly impact patients visual quality. Despite the identification of specific risk factors, manufacturing changes, opacifications are not eliminated. Likewise, more attention in recent studies was paid to possible new risk factors, however one of the most important purposes of the studies remains opacifications effect on visual performance, which could be disturbed in different aspects. The aim of this review is to discuss the main risk factors of IOLs opacification in particular IOL types, and its impact on vision quality. Different risk factors were discussed in the study, including the material of IOLs, the impact of the breakdown of blood-aqueous barrier (BAB), and certain surgeries that can be associated with opacification formation. Glistenings occur more often in a hydrophobic material, however, the changes in water content of the IOLs can significantly reduce the formation of glistenings. The studies showed a significant effect of intraocular injection of exogenous air or gas during Descemet-stripping endothelial keratoplasty, Descemet-stripping automated endothelial keratoplasty, Descemet membrane endothelial keratoplasty, and pars plana vitrectomy on calcification formation. It raises a concern, as the incidence of these surgeries is increasing. Visual acuity decreases significantly after the calcification in IOLs occurs, and it usually causes IOLs exchange. However, disability glare seems to be more affected in patients with IOLs, which were affected by glistenings than visual acuity. Disability glare is associated with increased levels of straylight, which was widely evaluated in recent studies and it was reported to be a susceptible measurement to detect the presence of IOLs pathology. For future researches, it should be noticed that disability glare and straylight are more appropriate in evaluating IOLs opacification effect on visual quality than visual acuity. While reviewing the main risk factors of IOLs opacifications particular attention must be paid on calcification occurrence in hydrophilic acrylic IOLs after surgeries with intraocular injection of exogenous air or gas.

Recent developments in the management of congenital cataract

Congenital cataract is a rare eye disease, one of the leading treatable causes of low vision in children worldwide. Hereditary cataracts can be divided in syndromic and non-syndromic cataracts. Early diagnosis in congenital cataracts is key to reach good visual function. Current surgical techniques, that combine microincision cataract extraction and primary intraocular lens (IOL) implantation, have improved childhood cataract outcome. Complications include posterior capsule opacification (PCO), aphakic or pseudophakic glaucoma, uveitis, pupil displacement and IOL decentration. A recent study using a modified Delphi approach identified areas of consensus and disagreement in the management of pediatric cataract. A consensus or near consensus was achieved for 79% of the questions, however 21% of the questions remained controversial, as for IOL implantation strategy. Congenital cataracts show a highly variable phenotype and genotype, and can be related to different mutations, genetic variance, and other risk factors. Congenital cataracts can be associated with other ocular developmental abnormalities, including microphthalmia, microcornea, or aniridia and with systemic findings. Next-generation sequencing (NGS) and forthcoming new ultra-high-throughput sequencing represent excellent tools to investigate the genetic causes of congenital cataracts. A better recognition of different clinical presentations and underlying etiologies of congenital cataracts may lead to the development of new approaches to improve visual outcome after cataract surgery and promote early detection of systemic associated syndromes.