scholarly journals Effect on rabbits’ intraocular structure by cross-linked hyaluronic formations as vitreous substitute

2019 ◽  
Author(s):  
Yan Gong ◽  
Kai Chen ◽  
Yue Wu ◽  
Xiaohong Guo ◽  
Tao Zhang
Keyword(s):  
Hyaluronic Acid ◽  
Intraocular Pressure ◽  
Uv Light ◽  
Vitreous Body ◽  
Polymer Materials ◽  
Vinyl Pyrrolidone ◽  
Synthetic Hydrogel ◽  
Vitreous Substitutes ◽  
Acid Test

Abstract Purpose: To observe the effects of cross-linked hyaluronic hydrogel on retina struct and intraocular biocompatibility in rabbits. Methods: the polymer-derived hyaluronic acid which was formed by UV light cross-linked with N-vinyl-pyrrolidone. Free hyaluronic acid levels were detected by spectrophotometric method. Vitrectomy was then performed in the rabbits, and then cross-linked hyaluronic acid hydrogels of different concentrations were injected. Intraocular pressure measurements, cornea check-up, and B-ultrasound examination were performed during the follow-up period. After six weeks’ follow-up, the rabbits were sacrificed, and both eyes were removed. The eyeballs were fixed for HE staining, and the polymer materials were observed under electron microscopy. Results: The synthetic hydrogel present a transparent substance with a refractive index similar to that of the human vitreous body, which also had sufficient viscosity and elasticity for intraocular usage by rheological measurements. The results of the free hyaluronic acid test showed that the hydrogel had little degrade within one month. The results of the histology, intraocular pressure, B-ultrasound and retinal ultrastructure suggested that cross-linked hyaluronic acid hydrogel had superior tissue biocompatibility intraocular for six weeks. Conclusions: Hyaluronic acid-based cross-linked biopolymers had good biocompatibility in rabbit, which also shown promising potential as vitreous substitutes in clinical practice.

Antibacterial catechol-based hyaluronic acid, chitosan and poly (N-vinyl pyrrolidone) coatings onto Ti6Al4V surfaces for application as biomedical implant

2021 ◽  
Author(s):  
Jon Andrade del Olmo ◽  
Leyre Pérez-Álvarez ◽  
Miguel Ángel Pacha-Olivenza ◽  
Leire Ruiz-Rubio ◽  
Oihane Gartziandia ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Vinyl Pyrrolidone ◽  
Biomedical Implant

scholarly journals The Use of Anterior-Segment Optical-Coherence Tomography for the Assessment of the Iridocorneal Angle and Its Alterations: Update and Current Evidence

2021 ◽  
Vol 10 (2) ◽  
pp. 231
Author(s):  
Giacinto Triolo ◽  
Piero Barboni ◽  
Giacomo Savini ◽  
Francesco De Gaetano ◽  
Gaspare Monaco ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Intraocular Pressure ◽  
Clinical Relevance ◽  
Anterior Segment ◽  
Angle Closure ◽  
Current Evidence ◽  
Optical Coherence ◽  
Iridocorneal Angle ◽  
Wide Range

The introduction of anterior-segment optical-coherence tomography (AS-OCT) has led to improved assessments of the anatomy of the iridocorneal-angle and diagnoses of several mechanisms of angle closure which often result in raised intraocular pressure (IOP). Continuous advancements in AS-OCT technology and software, along with an extensive research in the field, have resulted in a wide range of possible parameters that may be used to diagnose and follow up on patients with this spectrum of diseases. However, the clinical relevance of such variables needs to be explored thoroughly. The aim of the present review is to summarize the current evidence supporting the use of AS-OCT for the diagnosis and follow-up of several iridocorneal-angle and anterior-chamber alterations, focusing on the advantages and downsides of this technology.

scholarly journals Applications of Hyaluronic Acid in Ophthalmology and Contact Lenses

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2485
Author(s):  
Wan-Hsin Chang ◽  
Pei-Yi Liu ◽  
Min-Hsuan Lin ◽  
Chien-Ju Lu ◽  
Hsuan-Yi Chou ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Dry Eye ◽  
Water Retention ◽  
Contact Lenses ◽  
Anterior Segment ◽  
Vitreous Body ◽  
Material Surface ◽  
Connective Tissues ◽  
Water Retention Properties ◽  
Bull's Eye

Hyaluronic acid (HA) is a glycosaminoglycan that was first isolated and identified from the vitreous body of a bull’s eye. HA is ubiquitous in the soft connective tissues of animals and therefore has high tissue compatibility for use in medication. Because of HA’s biological safety and water retention properties, it has many ophthalmology-related applications, such as in intravitreal injection, dry eye treatment, and contact lenses. Due to its broad range of applications, the identification and quantification of HA is a critical topic. This review article discusses current methods for analyzing HA. Contact lenses have become a widely used medical device, with HA commonly used as an additive to their production material, surface coating, and multipurpose solution. HA molecules on contact lenses retain moisture and increase the wearer’s comfort. HA absorbed by contact lenses can also gradually release to the anterior segment of the eyes to treat dry eye. This review discusses applications of HA in ophthalmology.

scholarly journals A Case Study Supporting Lack of SARS-CoV-2 Spread to a 3-Month Old Infant Through Exclusive Breastfeeding

2021 ◽  
pp. 089033442199107 ◽  
Author(s):  
Wei Liu ◽  
Yujie Liu ◽  
Zhenjun Liu ◽  
Changxin Hong ◽  
Jian Liu ◽  
...  
Keyword(s):  
Male Infant ◽  
Computed Tomography Imaging ◽  
Full Data ◽  
Laboratory Findings ◽  
Global Pandemic ◽  
Breast Pump ◽  
Acid Test ◽  
Maternal And Newborn

Introduction During the Coronavirus Disease 2019 global pandemic, maternal and newborn wellbeing has received much attention. Detailed reports of infected women breastfeeding their infants are uncommon. Due to incomplete information available, full data about those infants’ outcomes are lacking, and evidence of infectivity through breastfeeding has not been documented. Main Issue Here, we report about a mother who breastfed her infant until she was confirmed with the SARS-Cov-2 infection. After follow-up, we have confirmed that the infant, who was breastfed by the infected mother, was not infected. Methods A 33-year-old woman gave birth to a full-term male infant on November 8, 2019. Since birth, she had been exclusively breastfeeding the baby until she was confirmed with the SARS-Cov-2 infection on February 8, 2020. She was hospitalized, isolated from her baby, and stopped breastfeeding. Even though she remained asymptomatic, her milk was expressed using a breast pump and discarded. The mother’s milk sample was collected on February 9, 2020, and the result of the nucleic acid test for COVID-19 was negative. Her infant was asymptomatic and remained virus negative. Her laboratory findings and chest Computed Tomography imaging was normal. She was treated according to the national protocol with aerosolized interferon α2β, lopinavir/ritonavir and ribavirin. Her serum SARS-CoV-2 specific antibodies(IgG and IgM) tested positive when discharged. She returned to breastfeeding after discharge. Conclusion Our findings suggest that breastfeeding may be less of a risk than anticipated. Additional research is needed to explore this possibility.

scholarly journals Urrets-Zavalia Syndrome Following Cataract Surgery

2021 ◽  
pp. 659-663
Author(s):  
Shimon Kurtz ◽  
Maayan Fradkin
Keyword(s):  
Intraocular Pressure ◽  
Case Report ◽  
Cataract Surgery ◽  
Anterior Chamber ◽  
Inflammatory Reaction ◽  
Intraocular Lens Implantation ◽  
Postoperative Course ◽  
Lens Implantation ◽  
The Right

We describe a case of Urrets-Zavalia syndrome (UZS) in a healthy 56-year-old woman who underwent femtosecond-assisted phacoemulsification with intraocular lens implantation in both eyes. One month after an uneventful postoperative course in the left eye, the right eye was operated. Dilated pupil which was nonreactive to light appeared on day 21 postoperatively. This was discovered upon examination following anterior chamber inflammatory reaction which occurred 2 weeks following her surgery. Our case report emphasizes the importance and danger in developing UZS even if the reaction in the anterior chamber does not occur immediately after surgery. In addition, the importance of intraocular pressure follow-up in the period after UZS is acknowledged.

scholarly journals Ologen augmentation of Ahmed glaucoma drainage devices in pediatric glaucomas

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Adam Jacobson ◽  
Carin Rojas ◽  
Brenda L. Bohnsack
Keyword(s):  
Intraocular Pressure ◽  
Pediatric Patients ◽  
Survival Rates ◽  
Collagen Matrix ◽  
Ahmed Glaucoma Valve ◽  
Limited Data ◽  
Conventional Surgery ◽  
Glaucoma Drainage Devices ◽  
Hypertensive Phase

Abstract Background Limited data exists on the effectiveness of the collagen matrix, Ologen, on increasing Ahmed glaucoma valve (AGV) success in childhood glaucomas. Methods Ocular examination and surgical details of pediatric patients who underwent AGV placement ± Ologen augmentation between 2012 and 2020. Complete success was defined as intraocular pressure (IOP) between 5 and 20 mmHg without glaucoma medications and additional IOP-lowering surgeries. Qualified success was defined as above, except IOP control maintained with or without glaucoma medications. Results Twenty-two eyes of 16 patients underwent AGV placement of which 6 eyes had Ologen-augmentation (OAGV) and 16 eyes had conventional surgery (CAGV). Average age was 6.4 ± 5.1 years with 4.2 ± 2.5 follow-up years. There was no difference in age, number of previous surgeries, and preoperative IOP and glaucoma medications. At final follow-up, success rate was 100% (5 eyes complete, 6 eyes qualified) in the OAGV group compared to 31% (0 eyes complete, 5 eyes qualified) in the CAGV group. One and two-year survival rates were 100% for OAGV compared to 62 and 38% for CAGV. Postoperative IOP was significantly lower at 1-month and final follow-up (p = 0.02) as was the number of glaucoma medications at 3, 6, 12-months and final follow-up (p < 0.05) in the OAGV group. Conclusions Ologen-augmentation increased the success and survival rates of AGVs in childhood glaucomas. Further, Ologen mitigated the hypertensive phase and decreased medication dependency. Longer follow-up with a greater number of eyes is required to fully evaluate the effectiveness of OAGV.

scholarly journals Chronic Glaucoma Using Biodegradable Microspheres to Induce Intraocular Pressure Elevation. Six-Month Follow-Up

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 682
Author(s):  
Maria Jesus Rodrigo ◽  
David Garcia-Herranz ◽  
Manuel Subias ◽  
Teresa Martinez-Rincón ◽  
Silvia Mendez-Martínez ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Clinical Signs ◽  
Progressive Increase ◽  
Biodegradable Microspheres ◽  
Fiber Layer ◽  
Chronic Glaucoma ◽  
Biodegradable Poly ◽  
Contralateral Eye

 Background: To compare two prolonged animal models of glaucoma over 24 weeks of follow-up. A novel pre-trabecular model of chronic glaucoma was achieved by injection of biodegradable poly lactic-co-glycolic acid (PLGA) microspheres (10–20 µm) (Ms20/10) into the ocular anterior chamber to progressively increase ocular hypertension (OHT). Methods: Rat right eyes were injected to induce OHT: 50% received a suspension of Ms20/10 in the anterior chamber at 0, 2, 4, 8, 12, 16 and 20 weeks, and the other 50% received a sclerosing episcleral vein injection biweekly (EPIm). Ophthalmological clinical signs, intraocular pressure (IOP), neuroretinal functionality measured by electroretinography (ERG), and structural analysis of the retina, retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) protocols using optical coherence tomography (OCT) and histological exams were performed. Results: Both models showed progressive neuroretinal degeneration (p < 0.05), and contralateral eye affectation. The Ms20/10 model showed a more progressive increase in IOP and better preservation of ocular surface. Although no statistical differences were found between models, the EPIm showed a tendency to produce thicker retinal and thinner GCL thicknesses, slower latency and smaller amplitude as measured using ERG, and more aggressive disturbances in retinal histology. In both models, while the GCL showed the greatest percentage loss of thickness, the RNFL showed the greatest and earliest rate of thickness loss. Conclusions: The intracameral model with biodegradable microspheres resulted more like the conditions observed in humans. It was obtained by a less-aggressive mechanism, which allows for adequate study of the pathology over longer periods. 

Ab interno 180-degree trabeculectomy with a dual blade in a patient with refractory primary congenital glaucoma

2021 ◽  
pp. 112067212110104
Author(s):  
Mehmet Talay Koylu ◽  
Fatih Mehmet Mutlu ◽  
Alper Can Yilmaz
Keyword(s):  
Intraocular Pressure ◽  
Female Patient ◽  
Congenital Glaucoma ◽  
Safe Procedure ◽  
Primary Congenital Glaucoma ◽  
History Of ◽  
Kahook Dual Blade ◽  
The Right ◽  
Ab Interno

A 13-year-old female patient with refractory primary congenital glaucoma (PCG) in the right eye who had a history of multiple glaucoma operations underwent ab interno 180-degree trabeculectomy with the Kahook Dual Blade (KDB) targeting the nasal and inferior angles. On postoperative day 1, the intraocular pressure (IOP) of the right eye reduced from 43 to 15 mmHg while on medical therapy. The patient maintained this IOP level throughout the 6-month follow-up. Ab interno KDB trabeculectomy targeting both nasal and inferior angles may be an effective and safe procedure for the treatment of PCG even in eyes with a history of previously failed glaucoma procedures.

scholarly journals Minimally Invasive Surgery for Intraocular Lens Removal and Intrascleral Intraocular Lens Fixation with Trabeculectomy in a Patient with Dislocated Intraocular Lens and Elevated Intraocular Pressure

2021 ◽  
pp. 538-542
Author(s):  
Yuko Mano ◽  
Kei Mizobuchi ◽  
Tomoyuki Watanabe ◽  
Akira Watanabe ◽  
Tadashi Nakano
Keyword(s):  
Intraocular Pressure ◽  
Intraocular Lens ◽  
Combined Therapy ◽  
Swept Source ◽  
Needle Technique ◽  
Elevated Intraocular Pressure ◽  
Anterior Segments ◽  
The Right ◽  
End Stage

A 88-year-old female who was being treated for end-stage pseudoexfoliation syndrome was referred to our hospital for treatment of dislocated intraocular lens (IOL) and the elevated intraocular pressure (IOP) and in the right eye (RE). At the first visit to our hospital, best-corrected visual acuity (BCVA) was 0.2 in the RE and 0.02 in the left eye (LE). IOP was 47 mm Hg in the RE and 21 mm Hg in the LE. Slit-lamp examination showed no abnormalities in anterior segments and dislocated IOL in the RE. Fundus photograph showed optic disc pallor in both eyes. We performed the combined therapy of flanged intrascleral IOL fixation with the double-needle technique and trabeculectomy. Throughout the follow-up period, BCVA slightly improved from 0.2 to 0.4 in the RE. The angle of tilt of the IOL was 6.6, 7.9, and 8.7° as measured by swept-source optical coherence tomography at 1, 4, and 6 months after the surgery, respectively. The IOP remained less than 10 mm Hg without having to administer any other glaucoma medications. Furthermore, any complications associated with the surgery were not confirmed.

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