-
Advanced Materials (Deerfield Beach,... May 2024Pathological ocular neovascularization resulting from retinal ischemia constitutes a major cause of vision loss. Current anti-VEGF therapies rely on burdensome...
Pathological ocular neovascularization resulting from retinal ischemia constitutes a major cause of vision loss. Current anti-VEGF therapies rely on burdensome intravitreal injections of Bevacizumab (Beva). Herein ultrasmall polymeric micelles encapsulating Beva (P@Beva) are developed for noninvasive topical delivery to posterior eye tissues. Beva is efficiently loaded into 11 nm micelles fabricated via self-assembly of hyperbranched amphiphilic copolymers. The neutral, brush-like micelles demonstrate excellent drug encapsulation and colloidal stability. In vitro, P@Beva enhances intracellular delivery of Beva in ocular cells versus free drug. Ex vivo corneal and conjunctival-sclera-choroidal tissues transport after eye drops are improved 23-fold and 7.9-fold, respectively. Anti-angiogenic bioactivity is retained with P@Beva eliciting greater inhibition of endothelial tube formation and choroid sprouting over Beva alone. Remarkably, in an oxygen-induced retinopathy (OIR) model, topical P@Beva matching efficacy of intravitreal Beva injection, is the clinical standard. Comprehensive biocompatibility verifies safety. Overall, this pioneering protein delivery platform holds promise to shift paradigms from invasive intravitreal injections toward simplified, noninvasive administration of biotherapeutics targeting posterior eye diseases.
PubMed: 38819852
DOI: 10.1002/adma.202314126 -
Canadian Journal of Ophthalmology.... May 2024To evaluate wolfram as a photon and beta absorber in the management of uveal melanoma with radiotherapy, examining its potential ocular adverse effects and physiologic... (Review)
Review
OBJECTIVE
To evaluate wolfram as a photon and beta absorber in the management of uveal melanoma with radiotherapy, examining its potential ocular adverse effects and physiologic tolerance using an in vivo rabbit ocular model.
METHODS
A method of manufacturing implants from mixtures of wolfram and silicone was developed. Their shielding effect on the radiation of sources used in ocular brachytherapy was investigated by dosimetric measurement in an eye phantom as well as numerical simulations. Different wolfram implantation techniques, such as extraocular fixation of a wolfram-silicone implant (n = 1), vitrectomy with silicone oil and intravitreal injection of a wolfram-silicone oil suspension (n = 2), and concurrent attachment of a wolfram implant onto the sclera (n = 2), were tested to investigate the long-term effects of wolfram. A vitrectomy with silicone oil without wolfram implantation was carried out in 2 rabbits (n = 2), constituting the control group. The eyes were enucleated after 3 months for histologic analysis.
RESULTS
Wolfram-silicone mixtures have been dosimetrically proven to be very effective radiation absorbers for use in ocular brachytherapy. Severe complications, such as endophthalmitis, secondary glaucoma, cornea decompensation, and vessel occlusion, were not documented in the tested rabbit eyes after the application of wolfram. Histologic examination of the bulbi after enucleation showed epiretinal gliosis without further pathologic findings in all eyes after vitrectomy.
CONCLUSIONS
The results of this study show that wolfram and wolfram-silicone implants constitute a promising candidate as potential radiation shielding substrates.
PubMed: 38815956
DOI: 10.1016/j.jcjo.2024.04.011 -
BMJ Case Reports May 2024A female in her 20s presented with a diminution of vision in the right eye (RE) following an open globe injury (scleral penetration) and repair a year back. At the...
A female in her 20s presented with a diminution of vision in the right eye (RE) following an open globe injury (scleral penetration) and repair a year back. At the presentation, she had low intraocular pressure (IOP) of 7 mm Hg, posterior subcapsular cataract (PSC), retrolental vitreous bands incarcerated at the penetration site, disc oedema, tortuous vessels and choroidal folds. Inferotemporal and superonasal cyclodialysis clefts were detected on CASIA 2 optical coherence tomography (OCT). The diagnosis of RE repaired scleral penetration, PSC and cyclodialysis cleft with hypotony maculopathy was made. The case was managed by phacoemulsification with an intraocular lens in the bag and a capsular tension ring in the sulcus, as a tamponading agent to close the cleft. Intraoperatively on endoscopic visualisation, vitreous membrane was noticed encasing the ciliary processes causing a tractional cyclodialysis and hence single port 23G pars plana vitrectomy was performed to relieve the traction. Postsurgery, IOP was 14 mm Hg, and the repaired cleft was visualised on anterior segment OCT.
Topics: Adult; Female; Humans; Cyclodialysis Clefts; Endotamponade; Eye Injuries, Penetrating; Intraocular Pressure; Phacoemulsification; Sclera; Tomography, Optical Coherence; Vitrectomy
PubMed: 38802253
DOI: 10.1136/bcr-2022-252123 -
American Journal of Ophthalmology Case... Sep 2024To report a 4-point scleral fixation technique utilizing Gore-tex® CV8 sutures and cut-out plated haptic intraocular lenses (IOLs) lacking a 4-eyelet haptic design for...
PURPOSE
To report a 4-point scleral fixation technique utilizing Gore-tex® CV8 sutures and cut-out plated haptic intraocular lenses (IOLs) lacking a 4-eyelet haptic design for aphakic patients.
OBSERVATIONS
This scleral fixation technique utilizes Gore-tex CV8® sutures paired with a foldable, monofocal, cut-out plated haptic IOLs wherein the sutures are passed through the holes of the plate haptics. Initially, sectoral conjunctival peritomies are performed on the temporal and medial conjunctiva. This is followed by the creation of 4 sclerotomy sites 5mm from each other and 2mm from the limbus at the exposed medial and temporal sclera. A Gore-Tex® (CV8) suture is threaded under the plate haptic. The leading suture is then inserted intraocularly through the corneal incision and externalized through the inferior sclerotomy. The trailing end of the suture which is over the haptic plate is passed intraocularly and externalized through the same port. The externalized suture is brought back intraocularly through the superior sclerotomy and then re-externalized through the corneal incision. This suture end is then threaded through the superior portion of the plate haptic in an over-under fashion. The suture which has passed under the haptic plate, is then brought back intraocularly through the corneal incision and externalized through the superior sclerotomy creating a loop. The same steps are then performed on the contralateral side. The IOL is then inserted. Centration of the IOL is then achieved by adjusting the tension on the 4 externalized suture ends. The Gore-Tex® sutures are then tied and subsequently buried into the sclerotomy. Conjunctival peritomies are then repaired.
CONCLUSIONS AND IMPORTANCE
Four-point fixation of cut-out plate haptic IOLs is achievable with predictable outcomes showing good centration, stability, visual and refractive outcomes providing surgeons additional options for fixation of available lenses as a secondary or primary implantation or by fixation of subluxed or dropped plate IOLs.
PubMed: 38799227
DOI: 10.1016/j.ajoc.2024.102071 -
Lasers in Medical Science May 2024The goal of this study was to compare the settings and effectiveness of the original P3 and revised P3 probes for micropulse transscleral cyclophotocoagulation. (Comparative Study)
Comparative Study
PURPOSE
The goal of this study was to compare the settings and effectiveness of the original P3 and revised P3 probes for micropulse transscleral cyclophotocoagulation.
METHODS
This retrospective cross sectional study includes a total of 56 patients with glaucoma who received micropulse transscleral cyclophotocoagulation. 32 patients received treatment with the original P3 probe and 24 received treatment with the revised P3 probe. Success was defined as a 20% reduction in intraocular pressure. Laser settings, pre-op and post-op intraocular pressures, and pre-op and post-op medications were assessed.
RESULTS
A 20% IOP reduction was achieved in 50% of patients in the original probe vs. 58.3% in the revised probe at one month (P = 0.536) and 71.9% vs. 50% at three months (P = 0.094), respectively. The revised P3 probe used higher values of power (2500 mW vs. 2023 mW, P < 0.0001), total duration (217 s vs. 179 s, P < 0.0001), and energy (170 J vs. 113 J, P < 0.001). There was a significant decrease in IOP lowering meds with the original probe at one month (-0.9 +/- 1.5 vs. -0.0 +/- 0.7, P = 0.010), but this was not seen at three months.
CONCLUSIONS
There is no significant difference in IOP lowering effect between probes despite the revised probe using higher total energy. The original probe may be associated with fewer medications at 1 month, but not at 3 months. Further studies with longer follow up are needed to optimize the treatment parameters in order to maximize effectiveness while limiting side effects.
Topics: Humans; Retrospective Studies; Female; Male; Cross-Sectional Studies; Middle Aged; Intraocular Pressure; Glaucoma; Laser Coagulation; Aged; Sclera; Treatment Outcome; Adult; Ciliary Body; Aged, 80 and over
PubMed: 38795228
DOI: 10.1007/s10103-024-04086-z -
Bioengineering (Basel, Switzerland) May 2024Postmortem human eyes were subjected to optic nerve (ON) traction in adduction and elevated intraocular pressure (IOP) to investigate scleral surface deformations. We...
Postmortem human eyes were subjected to optic nerve (ON) traction in adduction and elevated intraocular pressure (IOP) to investigate scleral surface deformations. We incrementally adducted 11 eyes (age 74.1 ± 9.3 years, standard deviation) from 26° to 32° under normal IOP, during imaging of the posterior globe, for analysis by three-dimensional digital image correlation (3D-DIC). In the same eyes, we performed uniaxial tensile testing in multiple regions of the sclera, ON, and ON sheath. Based on individual measurements, we analyzed eye-specific finite element models (FEMs) simulating adduction and IOP loading. Analysis of 3D-DIC showed that the nasal sclera up to 1 mm from the sheath border was significantly compressed during adduction. IOP elevation from 15 to 30 mmHg induced strains less than did adduction. Tensile testing demonstrated ON sheath stiffening above 3.4% strain, which was incorporated in FEMs of adduction tethering that was quantitatively consistent with changes in scleral deformation from 3D-DIC. Simulated IOP elevation to 30 mmHg did not induce scleral surface strains outside the ON sheath. ON tethering in incremental adduction from 26° to 32° compressed the nasal and stretched the temporal sclera adjacent to the ON sheath, more so than IOP elevation. The effect of ON tethering is influenced by strain stiffening of the ON sheath.
PubMed: 38790319
DOI: 10.3390/bioengineering11050452 -
Frontiers in Veterinary Science 2024This study investigates the relationship between ciliary muscle dynamics, thickness, and the regulation of intraocular pressure (IOP), focusing on the progression of...
INTRODUCTION
This study investigates the relationship between ciliary muscle dynamics, thickness, and the regulation of intraocular pressure (IOP), focusing on the progression of cataracts and changes post-phacoemulsification. It explores how these factors impact canine ocular health, particularly in the context of cataract development and subsequent surgical intervention.
MATERIALS AND METHODS
Data was collected using Ultrasound Biomicroscopy (UBM) from dogs at the Veterinary Medical Teaching Hospital of Chungbuk National University, Korea. The study involved 57 eyes from 35 dogs, categorized into five groups: 13 normal eyes, 14 with incipient cataracts, 12 with immature cataracts, 6 with mature cataracts, and 12 post-phacoemulsification. UBM measurements assessed various ciliary muscle parameters including ciliary body axial length (CBAXL), ciliary process-sclera angle (CPSA), longitudinal fibers of ciliary muscle thickness (Lf-CMT), and longitudinal and radial fibers of ciliary muscle thickness (LRf-CMT).
RESULTS
Findings indicated a decrease in CBAXL and an increase in Lf-CMT as cataracts progressed in severity. Post-phacoemulsification, there was a notable increase in CBAXL and a decrease in CPSA, Lf-CMT, and LRf-CMT, compared to both cataractous and normal eyes. Regression analysis revealed a significant positive association between CBAXL and IOP, alongside a negative association between Lf-CMT and IOP. These findings suggest that variations in ciliary muscle dynamics and thickness, as influenced by cataract progression and phacoemulsification, have distinct impacts on intraocular pressure.
DISCUSSION
The study proposes that phacoemulsification leads to ciliary muscle contraction, causing an inward and anterior movement of the ciliary muscle. This movement results in the narrowing of the ciliary cleft and constriction of the unconventional outflow pathway, potentially causing an increased risk of glaucoma post-surgery. Our research contributes to understanding the anatomical and physiological changes in the canine eye following cataract surgery and underscores the importance of monitoring IOP and ciliary muscle dynamics in these patients.
PubMed: 38784657
DOI: 10.3389/fvets.2024.1366997 -
Frontiers in Surgery 2024Heterotopic pancreas is a relatively rare condition that may be associated to clinical complaints or signs. Here, we report a case of gastric heterotopic pancreas...
Heterotopic pancreas is a relatively rare condition that may be associated to clinical complaints or signs. Here, we report a case of gastric heterotopic pancreas assictaed to ductal adenocarcinoma. Obstructive jaundice was the initial symptom prompting medical intervention. A 73-year-old male patient presented with yellow staining of the skin and sclera, and dull epigastric pain. Contrast-enhanced computed tomography showed stenosis of the extrahepatic distal bile duct and mass lesions of the antrum. The patient underwent tumor resection, distal gastrectomy (Billroth II), and common bile duct exploration. Postoperative pathological examination revealed an adenocarcinoma located in the wall of the gastric antrum. Immunohistochemical results suggested that the tumor originated from the pancreas. Heterologous pancreatic tissue and a dilated pancreatic duct were found in the tumor. These findings suggest malignant transformation of the gastric heterotopic pancreas. Of note, jaundice as clinical complaint for adenocarcinoma associated to gastric heterotopic pancreas.
PubMed: 38783861
DOI: 10.3389/fsurg.2024.1274389 -
Clinical Nuclear Medicine May 2024A 46-year-old man has a history of right eye vision loss from childhood due to an injury, right hypopharyngeal cancer with metastasis to right neck lymph nodes treated...
A 46-year-old man has a history of right eye vision loss from childhood due to an injury, right hypopharyngeal cancer with metastasis to right neck lymph nodes treated with concurrent chemoradiotherapy, and left tonsillar cancer after resection and adjuvant chemotherapy. Whole-body bone scan showed abnormal uptake to the right eye region, whereas SPECT/CT imaging localized this uptake to sharply defined, round to oval bone density foci of calcium scattered in the sclera and surrounding tissues, indicative of phthisis bulbi with posttraumatic calcification. Phthisis bulbi represents a shrunken ocular globe with calcification or ossification, typically as a sequela of trauma.
PubMed: 38778469
DOI: 10.1097/RLU.0000000000005290 -
The British Journal of Ophthalmology May 2024To investigate the effect of preretinal tractional structures (PTS) and posterior scleral structures (PSS) on myopic traction maculopathy (MTM) progression.
AIMS
To investigate the effect of preretinal tractional structures (PTS) and posterior scleral structures (PSS) on myopic traction maculopathy (MTM) progression.
METHODS
This retrospective cohort study included 185 fellow highly myopic eyes of 185 participants who underwent surgery for MTM. PTS included epiretinal membrane, incomplete posterior vitreous detachment and their combination. PSS included posterior staphyloma and dome-shaped macula (DSM). The MTM stage was graded according to the Myopic Traction Maculopathy Staging System. Optical coherence tomography was used to identify MTM progression, defined as an upgrade of MTM. The Kaplan-Meier method with log-rank test was used to assess MTM progression over the 3-year follow-up period. Risk factors for progression were identified using Cox regression analysis.
RESULTS
MTM progression was observed in 48 (25.9%) eyes. Three-year progression-free survival (PFS) rates for eyes with PTS, staphyloma and DSM were 53.7%, 58.2% and 90.7%, respectively. Eyes with PTS and staphyloma exhibited lower 3-year PFS rates than those without PTS or staphyloma ( =0.002 and <0.001), while eyes with DSM had a higher 3-year PFS rate than eyes without DSM ( =0.01). Multivariate Cox regression analysis showed that PTS (HR, 3.23; p<0.001) and staphyloma (HR, 7.91; p<0.001) were associated with MTM progression, whereas DSM (HR, 0.23; p=0.046) was a protective factor.
CONCLUSION
Both PTS and PSS play a critical role in the progression of MTM. Addressing these factors can aid in the management of MTM.
PubMed: 38777388
DOI: 10.1136/bjo-2024-325274