The purpose of this article was to look at the pathophysiology behind and devise a classification system for the causes of zonular apparatus-capsular bag (ZACB) insufficiency. Also discussed is ...dystrophic bag syndrome, including clinical cases and addressing where it lies on the ZACB spectrum. There has been interest in the emergence of in-the-bag intraocular lens (IOL) subluxation, the prevalence of which is increasing. There has also been a recent report of dead bag syndrome, which the authors believe is part of the same disease spectrum. The authors put these phenomena into perspective and provide a classification system based on the possible causes of what they have termed ZACB insufficiency. The basic aspects of capsular bag-IOL ocular pathophysiology are summarized with a focus on functional aspects and the consequences for IOL fastening. Within this framework, dystrophic bag syndrome is a form of primary capsular ZACB insufficiency. The contribution of factors such as intraocular drugs may suggest a reconsideration of agents used and their mode of application.
Bipolar eyes: Windows to the pole? Parker, Gordon; Coroneo, Minas T; Spoelma, Michael J
Australian and New Zealand journal of psychiatry,
11/2023, Letnik:
57, Številka:
11
Journal Article
Purpose: Recent advancements in infrared sensing technology have made it possible to visualize tear film dynamics in real time, enabling evaluation of tear film quality during blinking. A ...retrospective clinical evaluation was conducted to explore this by grading videos of the tear film and comparing grading data with dry eye diagnostic results using the OCULUS keratograph (K5M). Methods: Videos were used to grade patients’ tear film perturbations as compared with healthy control subjects. The grading was then correlated with the ocular surface disease index (OSDI) scores, tear film breakup time (TFBUT), tear meniscus height (TMH), corneal staining, redness, and meibography data. Results: Infrared imaging of the ocular surface revealed instantaneous and recurring dynamic characteristics of the tear film, allowing for the differentiation between normal and abnormal tear films. Abnormal features included a complete absence of a spreading tear film, hindered spreading of the tear film after blinking, areas of tear film instability, or a combination of the latter 2. Some of these features show a resemblance to the tear film appearance after fluorescein staining. The grading of these features correlated with TFBUT and, to a lesser extent, with TMH but did not show significant correlation with any other diagnostic data from the K5M. Furthermore, the speed of tear film spreading after blinking showed a positive correlation with TMH. Conclusions: Direct visualization of the tear film across the entire palpebral aperture using infrared sensing offers a noninvasive, reproducible, and rapid method for assessing the health and quality of the tear film.
Pterygia are common ocular surface lesions thought to originate from limbal stem cells altered by chronic UV exposure. Traditionally regarded as a degenerative condition, pterygia also display ...tumor-like features, such as a propensity to invade normal tissue and high recurrence rates following resection, and may coexist with secondary premalignant lesions. This study was initiated to determine the rate of concurrent ocular surface diseases in patients with pterygia recruited from the practice of a single surgeon operating in a Sydney metropolitan hospital. One hundred pterygium specimens were histopathologically reviewed and selected cases were immunohistochemically assessed to confirm diagnosis. Along with previously documented typical features including epithelial proliferation, goblet cell hyperplasia, angiogenesis, inflammation, elastosis, stromal plaques, and Bowman's membrane dissolution, we identified five cases of ocular surface squamous neoplasia, six cases of primary acquired melanosis, two compound nevi (one suspect invasive melanoma), and one dermoid-like lesion. In 18 specimens, clusters of basal epithelial cells that coexpressed cytokeratin-15/-19 and p63-α were identified at the head of the pterygium, coinciding with clinical observation of Fuchs' flecks. Our data show that significant preneoplastic lesions may be associated with pterygium and that all excised pterygia should undergo histological examination. The presence of p63-α-positive epithelial cell clusters supports the hypothesis that pterygia develop from limbal epithelial progenitors.
Glaucoma surgery with implantation of aqueous humor draining microstents may compromise long-term corneal health by disrupting aqueous humor circulation. The effect of stent numbers on this ...circulation was interrogated to determine the number of stents associated with minimal circulation disruption. An in vitro anterior eye model perfusion system was constructed with multiple exit ports. A 3-D model of the anterior eye was imported into ABAQUS CFD, analyzes were carried out for unsteady laminar flow and solved using Navier-Stokes equations. DT Vision Foundry was used to analyze velocity contour plot images. The field variable results output for the CFD model were fluid wall shear, fluid pressure and fluid velocity. In vitro, “aqueous” fluid flow is high through a single stent and “aqueous” stagnation is greatest in the quadrants 180° away. Increasing stent port numbers, results in an exponential decrease in the stagnant flow locations. High wall shear stress was seen in the single stent model and is markedly reduced after a second and subsequent stents are introduced. We identify two factors potentially contributing to corneal compromise post glaucoma drainage surgery: aqueous humor stagnation, remote to the stent site and higher exit flows imparting increased stent exit shear stress (particularly with a single stent). With 4 stents, there is minimal disruption of anterior chamber circulation (mimicking physiological conditions). Furthermore we propose that aqueous humor circulation disruption via the usual single-exit port approach disrupts aqueous humor circulation with long-term consequences for corneal health.
•Reusable Drysdale manipulators are widely used in cataract surgery.•Damage or residues can accumulate with instrument reuse.•Scanning electron microscopy found sharp defects in all (5 of 5) reused ...instruments.•Defects had elemental composition mainly of carbon or aluminum.•Sharp defects may contribute to complications including posterior capsule rupture.
To analyze microtopography of 5 reusable Drysdale nucleus manipulator (DNM) paddled tips for sharp defects and evaluate their elemental composition to determine probable source, investigating 2 instruments (DNM 1 and 4) implicated in causing posterior capsule rupture (PCR) and 3 instruments with sharp edges identified by finger-tip interrogation intraoperatively.
Experimental laboratory investigation.
DNM paddled tips were analyzed using scanning electron microscopy (SEM) to evaluate for sharp surface defects (number, dimensions), and subsequently energy dispersive x-ray spectroscopy (EDS) performed on sharp defects to determine their elemental composition.
All reused DNMs analyzed (5 of 5) had significant structural defects on SEM analysis including sharp burrs, cavities and indentations, surface debris or residues, and roughening, compared to the new instrument (DNM 3, control) which had no defects. DNM 1 had 2 sharp defects, a larger 14 × 76-µm one and a craterlike 167 × 220-µm defect containing debris. EDS found that DNM 2 had 3 of 4 burrs composed mainly of carbon, the fourth of mixed composition (calcium, sulfur, oxygen); DNM 4 had 1 small burr, EDS significant for carbon; DNM 5 had 3 prominent burrs, the largest of 20 × 28 µm, 2 composed of aluminum, and some carbon residue. DNM 6 had 1 burr composed of aluminum and 3 prominent cavity defects, the largest covering 781 µm2.
Reusable DNMs are widely used in cataract surgery. Sharp carbon- or aluminum-containing burrs were detected on all reused instruments analyzed together with 1 burr of mixed composition, originating from (1) organic residues, (2) instrument fragments, or (3) salt and contaminant deposits. Sharp defects may contribute to capsular damage including PCR, and residues may pose other safety concerns. Therefore, we support development of a quality, reliable single-use alternative instrument and further encourage careful inspection of all reusable instruments principally by finger-tip interrogation for sharp edges preuse.
Myopia (near-sightedness) is an important public health issue. Spending more time outdoors can prevent myopia but the long-term association between this exposure and myopia has not been well ...characterised. We investigated the relationship between time spent outdoors in childhood, adolescence and young adulthood and risk of myopia in young adulthood. The Kidskin Young Adult Myopia Study (KYAMS) was a follow-up of the Kidskin Study, a sun exposure-intervention study of 1776 children aged 6-12 years. Myopia status was assessed in 303 (17.6%) KYAMS participants (aged 25-30 years) and several subjective and objective measures of time spent outdoors were collected in childhood (8-12 years) and adulthood. Index measures of total, childhood and recent time spent outdoors were developed using confirmatory factor analysis. Logistic regression was used to assess the association between a 0.1-unit change in the time outdoor indices and risk of myopia after adjusting for sex, education, outdoor occupation, parental myopia, parental education, ancestry and Kidskin Study intervention group. Spending more time outdoors during childhood was associated with reduced risk of myopia in young adulthood (multivariable odds ratio OR 0.82, 95% confidence interval CI 0.69, 0.98). Spending more time outdoors in later adolescence and young adulthood was associated with reduced risk of late-onset myopia (≥ 15 years of age, multivariable OR 0.79, 95% CI 0.64, 0.98). Spending more time outdoors in both childhood and adolescence was associated with less myopia in young adulthood.
To review the literature on crystalline lens epithelial cell (LEC) removal in routine phacoemulsification and determine whether it should be incorporated as part of a surgeon's standard technique.
...Perspective.
Expert commentary with video demonstrations on techniques of removal of LECs and associated potential complications. Discussion incorporates the importance of LEC removal, a review of techniques to prevent posterior capsular opacification (PCO), and the effects of intraocular lens design on LEC proliferation and PCO.
The evidence suggests that LEC removal should be routinely performed as it can be carried out safely and with considerable short- and long-term benefits for patients. With effective cleanup, there is reduced anterior capsule opacification, fibrosis, and decentration of the capsular bag as well as reduced rates of posterior capsular opacification. Techniques for removal are easy to learn, with very low complication rates, and can reduce the risk of the long-term need for technically complex procedures such as intraocular lens explantation.
LEC removal from both the anterior and posterior capsule is part of a continuous, incremental improvement of cataract surgery and should be introduced to ophthalmology trainees during their formative years as part of their regular cataract surgery armamentarium.
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