Spotlight on Asteroid Hyalosis: A Clinical Perspective

Material Analysis of Explanted Calcified Silicone Intraocular Lenses in Association with Asteroid Hyalosis

INTRODUCTION

The aim of this study was to analyze posterior surface opacification in explanted silicone intraocular lenses (IOLs) with clinicopathologic correlation to asteroid hyalosis.

METHODS

In a laboratory setup, 12 explanted silicone IOLs underwent laboratory analyses, including light microscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy for elemental composition (EDX). Relevant clinical data were obtained for each case, including gender, age at IOL implantation, dates of implantation and explantation, as well as history of neodymium-dopped yttrium aluminum garnet (Nd:YAG) laser treatments or other opacification removal attempts. High-resolution optical coherence tomography (OCT) images were obtained in vitro with an anterior segment OCT device (Anterion, Heidelberg Engineering, Heidelberg, Germany).

RESULTS

Calcification located at the posterior optic surface of each lens was identified through SEM and EDX analyses, revealing deposits composed of hydroxyapatite. In all cases, IOL polishing using Nd:YAG laser had been attempted prior to IOL exchange. The clinical functional data showed that this type of IOL opacity led to increase in straylight and subjective symptoms of glare.

CONCLUSIONS

Silicone IOLs can develop posterior surface calcification in eyes with asteroid hyalosis. There are mechanical techniques of cleaning the IOL surface but in many cases, IOL explantation is the only sustainable way to reduce the patients' straylight levels and glare symptoms. Due to the risk of posterior surface calcification, silicone IOL implantation should be avoided in eyes with asteroid hyalosis.

Asteroid Hyalosis: A Mimicker of Vitreous Hemorrhage on Point of Care Ultrasound: A Case Report

Ocular point of care ultrasound (POCUS) can help make timely recognition of multiple emergent ocular conditions and differentiate these from more benign conditions. While asteroid hyalosis (AH) is benign, it can easily mimic the more potentially serious vitreous hemorrhage on ocular POCUS, as both consist of numerous echogenic opacities within the vitreous with a classic "washing machine" appearance with eye movement. However, asteroid hyalosis particles tend to be more discrete, hyperechoic, scintillating, and seen throughout the vitreous. Knowledge of this mimic and ability to recognize the subtle sonographic differences can help differentiate these disease processes, which can influence management and potentially disposition.

Role of the Vitreous in Retinal Pathology: A Narrative Review

The vitreous body is an anatomically and biochemically complex structure. Because of its proximity and firm adherence to the retina, researchers have examined the link between these two structures and how their individual pathologies might be connected. Several experimental and clinical studies have already demonstrated the important role of vitreous in the pathogenesis of retinal disorders. This narrative review highlights the role of the vitreous in retinal diseases and the improvements that have been made since the introduction of optical coherence tomography. This leads to a better understanding of vitreoretinal diseases and demonstrates its determinant role in other retinal pathologies, such as diabetic retinopathy or age-related macular degeneration. As we deepen our knowledge of the vitreous's structure, function, and abnormal conditions, we can better link the changes in diseases and identify effective treatments.

Asteroid Hyalosis: An Update on Prevalence, Risk Factors, Emerging Clinical Impact and Management Strategies

Asteroid hyalosis (AH) is a benign clinical entity characterized by the presence of multiple refractile spherical calcium and phospholipids within the vitreous body. First described by Benson in 1894, this entity has been well documented in the clinical literature and is named due to the resemblance of asteroid bodies on clinical examination to a starry night sky. Today, a growing body of epidemiologic data estimates the global prevalence of asteroid hyalosis to be around 1%, and there is a strong established association between AH and older age. While pathophysiology remains unclear, a variety of systemic and ocular risk factors for AH have recently been suggested in the literature and may provide insight into possible mechanisms for asteroid body (AB) development. As vision is rarely affected, clinical management is focused on differentiation of asteroid hyalosis from mimicking conditions, evaluation of the underlying retina for other pathology and consideration of vitrectomy in rare cases with visual impairment. Taking into account the recent technologic advances in large-scale medical databases, improving imaging modalities, and the popularity of telemedicine, this review summarizes the growing body of literature of AH epidemiology and pathophysiology and provides updates on the clinical diagnosis and management of AH.