With the aid of ophthalmological, morphological, biomechanical and regulation theory methods the inconsistency of prevalent concepts on the functional interpretation of morphological structure of ciliary zonule was demonstrated and the scheme of functioning of its elements matching clinical and physiological observations was proposed. The role of anterior and posterior portions of ciliary zonule appears to be functionally essential and consistent with accommodation mechanism proposed by Helmholtz, while the role of cilioequatorial fibers of ciliary zonule is functionally auxiliary. Morphological and constructive peculiarities of ciliary zonule structure confirm the validity of Helmholtz concepts of accommodation mechanism.
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Cureus
December 2024
Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, JPN.
Objectives This study aimed to identify the etiology and the direction of dislocation of the natural crystalline lens or intraocular lens (IOL) in IOL intrascleral fixation surgery and to determine the change in intraocular pressure (IOP) after surgery. Methods We retrospectively investigated the diagnosis, direction of lens and IOL dislocation, and IOP before and after surgery (preoperatively and one day, one week, and one month postoperatively) in 236 eyes from 228 patients who underwent IOL intrascleral fixation at Chiba University Hospital between February 2015 and September 2020. Results IOL intrascleral fixation was performed in 48 (20.
View Article and Find Full Text PDFCells
December 2024
Department of Ophthalmology & Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
Marfan syndrome is an inherited connective tissue disorder that affects the cardiovascular, musculoskeletal, and ocular systems. It is caused by pathogenic variants in the fibrillin-1 gene (). Fibrillin is a primary component of microfibrils, which are found throughout the extracellular matrix (ECM) and provide elasticity and resilience to connective tissue.
View Article and Find Full Text PDFGenes (Basel)
December 2024
Department of Ophthalmology, Southend University Hospital, Southend-on-Sea SS0 0RY, UK.
The zonular fibres are formed primarily of fibrillin-1, a large extracellular matrix (ECM) glycoprotein, and also contain other constituents such as LTBP-2, ADAMTSL6, MFAP-2 and EMILIN-1, amongst others. They are critical for sight, holding the crystalline lens in place and being necessary for accommodation. Zonulopathies refer to conditions in which there is a lack or disruption of zonular support to the lens and may clinically be manifested as ectopia lens (EL)-defined as subluxation of the lens outside of the pupillary plane or frank displacement (dislocation) into the vitreous or anterior segment.
View Article and Find Full Text PDFSci Rep
December 2024
Visual Optics Lab Antwerp (VOLANTIS), Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.
In cataract surgery, post-surgical stability of the intraocular lens plays a major role. This study aims to explore how the size and decentration of the capsulorhexis affect intraocular lens decentration and tilt by using numerical methods. Finite element models included zonules, ciliary body, capsular bag, and an IOL with two open-loop haptics were built.
View Article and Find Full Text PDFMed Hypothesis Discov Innov Ophthalmol
August 2024
Department of Ophthalmology, 251 Hellenic Airforce General Hospital, Athens, Greece.
Background: Pseudoexfoliation syndrome (PES) is an age-related systemic condition that predominantly affects ocular structures and is characterized by the deposition of material on the lens, ciliary body, zonules, corneal endothelium, iris, and pupillary margin. We compared the corneal endothelial morphology, anterior segment parameters, corneal densitometry, and corneal topographic characteristics between the clinically affected and apparently normal fellow eyes of patients with clinically unilateral PES.
Methods: This was a comparative, cross-sectional study of 34 patients with clinically unilateral PES.
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