Microscopic Characteristics of Late Intraocular Lens Opacifications

Abstract

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 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.

Eintrübung von Intraokularlinsen: Erkenntnisse aus dem Labor und der Klinik

“…Dementsprechend werden heute eher andere Komplikationen beobachtet, welche im Zusammenhang mit diesen Materialien stehen. Während bei hydrophilen IOL v. a. eine Kalzifikation des Materials zur Eintrübung der Linse führen kann, überwiegt bei manchen Linsen aus hydrophobem Material das Auftreten von Glistenings [ 16 ].…”

Comparative analysis of in vitro accelerated glistening formation in foldable hydrophobic intraocular lenses

“…Furthermore, the osmolarity of the fluid around the IOL may play a role as do comorbidities of the patients such as diabetes mellitus. Inflammations or an interrupted blood-aqueous barrier may also influence the outcome in every patient [1][2][3].…”

“…Glistenings describe small, refractive microvacuoles that arise within the biomaterial of intraocular lenses (IOLs) [1][2][3][4]. Studies have reported on their clinical significance as they may deteriorate the patients' visual acuity and contrast sensitivity [5][6][7][8][9][10].…”

Eintrübung von Intraokularlinsen

“…Klinische Studien haben gezeigt, dass Glistenings den Visus kaum zu reduzieren scheinen. Aber insbesondere nachts bei Vorhandensein von Gegenlicht oder unter sonnigen Bedingungen können Blendsymptome auftreten [2,3]. Mithilfe eines In-vitro-Modells wurde evaluiert, inwiefern Glistenings die Sehqualität beeinflussen.…”