Iridodialysis Repair With Intrascleral Fixation of Flattened Flanged Polypropylene Suture

PURPOSE

To present the flattened flanged polypropylene suture technique developed to obtain round and stable pupils in patients with iridodialysis.

METHODS

After performing a fornix-based conjunctival peritomy, a flange was created at the tip of a 6.0 polypropylene suture by cautery. In the quadrant of iridodialysis, an ultrathin 30-gauge needle was inserted into the sclera at a distance of 2 mm from the limbus and advanced 1.5 mm intrasclerally, parallel to the limbus. The needle was directed radially into the eye and easily passed through the edge of the peripheral iris. The polypropylene suture was pushed into the lumen of the needle with the help of forceps. After the needle was externalized, the tip of the suture was flanged by cautery, and the flange was immediately flattened using a needle holder.

RESULTS

Six eyes of six patients with iridodialysis were enrolled in this study. Postoperatively, the irises remained well positioned and the pupils became round in all eyes. None of the patients developed suture erosion, suture loosening or rupture, hyphema, hypotony, chronic iridocyclitis, and angle closure.

CONCLUSION

The present technique provides a minimally invasive surgery and robust iris fixation without the need to create a scleral flap, groove, or pocket.

Modified early intensive and treat-and-extend regimen of anti-vascular endothelial growth factor for diabetic macular edema in Taiwan

Given the rising prevalence of patients with diabetes and increasing treatment burden for patients with vision-threatening diabetic macular edema (DME), we aimed to explore the efficacy of modified early intensive and treat-and-extend regimen of anti-vascular endothelial growth factor (VEGF) therapy under the Taiwan National Insurance Bureau reimbursement policy. We obtained data on 69 eyes treated with initial 4-monthly intravitreal injections of aflibercept or ranibizumab, plus individualized treat-and-extend regimen. At 12 months, the mean (SD) change in LogMAR best corrected visual acuity from baseline was - 0.28 (0.31) in all eyes, while that in the aflibercept and ranibizumab groups were - 0.30 (0.34) and - 0.25 (0.28), respectively. Central retinal thickness decreased by 137.2 (122.4) in all eyes, 138.1 (134.2) in the aflibercept group, and 136.2 (110.9) in the ranibizumab group. Additionally, the aflibercept group had a lower mean number of injections than the ranibizumab group (8.5 vs. 8.7). The last extended dosing interval of > 12 weeks was 31.0% and 16.7% of the eyes in the aflibercept and ranibizumab groups, respectively. The modified anti-VEGF regimens effectively managed DME in terms of functional and anatomical outcomes, and efficiently reduced the healthcare burden by reducing the number of injections and extending treatment intervals within 12 months.

Aflibercept monotherapy versus aflibercept with targeted retinal laser to peripheral retinal ischemia for diabetic macular oedema (LADAMO)

OBJECTIVE

We tested the hypothesis that targeted retinal laser photocoagulation (TPRP) to peripheral retinal ischaemia reduces the overall burden of aflibercept injections when treating diabetic macular oedema (DMO) over a 24-month period.

METHODS

Prospective, double-masked, multicentre, randomised controlled trial in Australia comparing aflibercept monotherapy, following a treat-and-extend protocol, or combination therapy of aflibercept and TPRP for DMO. The aflibercept monotherapy group received placebo laser. The primary outcome measure was the mean number of intravitreal aflibercept injections for each group at 24 months. Secondary outcome included: mean change in central macular thickness (CMT) and vision at trial completion, the proportion of eyes whose DMO resolved and the mean injection treatment interval. Ocular and systemic adverse events were recorded.

RESULTS

We enrolled 48 eyes of 47 patients; 27 eyes were randomised to combination therapy (aflibercept and TPRP) and 21 to aflibercept monotherapy. Thirty-two eyes (67%) completed the 2-year study. The number of intravitreal treatments given were similar for combination therapy (10.5 (SD 5.8) and monotherapy (11.8 (SD5.6)) (P = 0.44). The mean visual improvement (+4.0 (-1.8, 9.8) and +7.8 (2.6, 12.9) letters, P = 0.32), mean decrease in CMT (-154 (-222,-87) µm and -152 (-218,-86) µm, P = 0.96), proportion of eyes with CMT < 300 µm (48% and 67%; P = 0.50) and safety outcomes were similar in both the combination and monotherapy treatment groups (respectively).

CONCLUSIONS

Laser to areas of ischaemic peripheral retina does not reduce the burden of intravitreal aflibercept injections when treating diabetic macular oedema.

Outbreaks of Fungal Infections in Hospitals: Epidemiology, Detection, and Management

Nosocomial clusters of fungal infections, whilst uncommon, cannot be predicted and are associated with significant morbidity and mortality. Here, we review reports of nosocomial outbreaks of invasive fungal disease to glean insight into their epidemiology, risks for infection, methods employed in outbreak detection including genomic testing to confirm the outbreak, and approaches to clinical and infection control management. Both yeasts and filamentous fungi cause outbreaks, with each having general and specific risks. The early detection and confirmation of the outbreak are essential for diagnosis, treatment of affected patients, and termination of the outbreak. Environmental sampling, including the air in mould outbreaks, for the pathogen may be indicated. The genetic analysis of epidemiologically linked isolates is strongly recommended through a sufficiently discriminatory approach such as whole genome sequencing or a method that is acceptably discriminatory for that pathogen. An analysis of both linked isolates and epidemiologically unrelated strains is required to enable genetic similarity comparisons. The management of the outbreak encompasses input from a multi-disciplinary team with epidemiological investigation and infection control measures, including screening for additional cases, patient cohorting, and strict hygiene and cleaning procedures. Automated methods for fungal infection surveillance would greatly aid earlier outbreak detection and should be a focus of research.

Targeting posterior eye infections with colloidal carriers: The case of Ganciclovir

The ocular system, unlike any other human body organ, is a system in which foreign bodies appear quite defenceless in front of the eye. Several infections of the ocular system occur due to various opportunistic conditions. Cytomegalovirus (CMV) is one of the opportunivores that causes several posterior eye infections. Ganciclovir (GCV),9-(2-hydroxy-1-(hydroxymethyl) ethoxymethyl), is aguanine-antiviral agent primarily used to treat CMV diseases. However, the major challenge is of lower bioavailability. Hence, GCV must be dosed repeatedly to enhance drug absorption. but this causes side effects like neutropenia and bone marrow suppression. So, formulators have used alternative formulation strategies such as prodrug formulation and colloidal drug delivery systems. In the prodrug strategy, they attempted to bind various compounds into the parent drug to increase the permeability and bioavailability of GCV. In colloidal drug delivery systems, mucoadhesive microspheres, nanoparticles, Niosome and liposome were employed to extend the drug residence time at the application site. This paper discusses several colloidal carriers combined with GCV to treat opportunistic CMV infection in the posterior ocular system. It reviews the limitations of conventional ocular therapy and explores various novel formulation approaches to improve the ocular bioavailability of GCV in the posterior chamber of the eye.

Molecular and Phenotypic Characterization of Ocular Methicillin-Resistant Staphylococcus epidermidis Isolates in Taiwan

Purpose

Staphylococcus epidermidis, a commensal, has emerged as an important opportunistic pathogen, particularly methicillin-resistant S. epidermidis (MRSE). The mechanism behind this transformation remains unclear. This study aimed to investigate the molecular and phenotypic characteristics of MRSE isolated from healthy conjunctiva and ocular infections.

Methods

We collected MRSE isolates from two groups: healthy conjunctiva from patients undergoing cataract surgeries and ocular infections at our hospital. Genotypic analysis included pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec), and biofilm-related genes (icaA, aap, and bhp). Additionally, phenotypic data on biofilm production and antibiotic susceptibility were recorded.

Results

A total of 86 isolates, including 42 from healthy conjunctiva and 44 from ocular infections, were analyzed. MLST identified 21 sequence types (STs), with ST59 being the most frequent (n = 33, 39.5%), followed by ST130 (n = 10, 11.6%), ST57 (n = 6, 7.0%), and ST2 (n = 6, 7.0%). All isolates were categorized in 23 PFGE types, and SCCmec IV was the most prevalent SCCmec type (n = 52, 60.5%). The two sources of isolates exhibited overlapping molecular types and phenotypic traits, although the ocular infection isolates exhibited significantly higher multidrug resistance compared to healthy conjunctiva isolates (P = 0.032). When contrasting ST59 with non-ST59, ST59 displayed a significantly higher presence of aap (100%) and bhp (69.7%) while lacking icaA (0%). ST59 also showed lower susceptibility to fluoroquinolones compared to non-ST59 (42.4%-54.5% vs. 75.5%-83.0%; P < 0.01).

Conclusions

MRSE isolates from healthy conjunctiva and ocular infections demonstrated a degree of resemblance. Specific strains, notably ST59, exhibited distinctive characterizations.

Metabolic transcriptomics dictate responses of cone photoreceptors to retinitis pigmentosa

Most mutations in retinitis pigmentosa (RP) arise in rod photoreceptors, but cone photoreceptors, responsible for high-resolution daylight and color vision, are subsequently affected, causing the most debilitating features of the disease. We used mass spectroscopy to follow 13C metabolites delivered to the outer retina and single-cell RNA sequencing to assess photoreceptor transcriptomes. The S cone metabolic transcriptome suggests engagement of the TCA cycle and ongoing response to ROS characteristic of oxidative phosphorylation, which we link to their histone modification transcriptome. Tumor necrosis factor (TNF) and its downstream effector RIP3, which drive ROS generation via mitochondrial dysfunction, are induced and activated as S cones undergo early apoptosis in RP. The long/medium-wavelength (L/M) cone transcriptome shows enhanced glycolytic capacity, which maintains their function as RP progresses. Then, as extracellular glucose eventually diminishes, L/M cones are sustained in long-term dormancy by lactate metabolism.

Delayed-onset micrococcus luteus-induced postoperative endophthalmitis several months after cataract surgery: A case report

BACKGROUND

Micrococcus luteus (M. luteus)-induced endophthalmitis is very rare and and may present as either acute or chronic postoperative endophthalmitis. The aim of this study was to report a case of delayed-onset M. luteus-induced endophthalmitis that occurred several months after cataract surgery.

CASE SUMMARY

A 78-year-old man presented with decreased vision, pain and redness in the right eye that had begun 3 days prior. He had undergone cataract surgery 4 mo prior. Visual acuity was counting fingers; slit-lamp examination revealed conjunctival injection, posterior corneal precipitates, anterior chamber inflammation (cell 4+), and hypopyon. Fundus examination revealed moderate vitreous haze. Urgent vitrectomy was performed for suspected infectious endophthalmitis, followed by vitreous irrigation with injections of antibiotics. On the postoperative day 1, anterior chamber cell decreased to 2+ and hypopyon was not observed on slit lamp examination. Six days postoperatively, the patient had recurrent eye pain, and the anterior chamber cell grade increased to 4+; hypopyon recurred in the anterior chamber, and whitish plaque was observed in the lens capsule. Therefore, the patient underwent intraocular lens (IOL) and lens capsule removal, followed by vitreous irrigation, antibiotics injection, and vitrectomy. M. luteus was identified from a lens capsule culture.

CONCLUSION

In cases of delayed-onset M. luteus-induced endophthalmitis, early vitrectomy and removal of the IOL and lens capsule may be necessary.

Global research of artificial intelligence in strabismus: a bibliometric analysis

Purpose

To analyze the global publications on artificial intelligence (AI) in strabismus using a bibliometric approach.

Methods

The Web of Science Core Collection (WoSCC) database was used to retrieve all of the publications on AI in strabismus from 2002 to 2023. We analyzed the publication and citation trend and identified highly-cited articles, prolific countries, institutions, authors and journals, relevant research domains and keywords. VOSviewer (software) and Bibliometrix (package) were used for data analysis and visualization.

Results

By analyzing a total of 146 relevant publications, this study found an overall increasing trend in the number of annual publications and citations in the last decade. USA was the most productive country with the closest international cooperation. The top 3 research domains were Ophthalmology, Engineering Biomedical and Optics. Journal of AAPOS was the most productive journal in this field. The keywords analysis showed that "deep learning" and "machine learning" may be the hotspots in the future.

Conclusion

In recent years, research on the application of AI in strabismus has made remarkable progress. The future trends will be toward optimized technology and algorithms. Our findings help researchers better understand the development of this field and provide valuable clues for future research directions.

Artificial intelligence-aided diagnosis and treatment in the field of optometry

With the rapid development of computer technology, the application of artificial intelligence (AI) to ophthalmology has gained prominence in modern medicine. As modern optometry is closely related to ophthalmology, AI research on optometry has also increased. This review summarizes current AI research and technologies used for diagnosis in optometry, related to myopia, strabismus, amblyopia, optical glasses, contact lenses, and other aspects. The aim is to identify mature AI models that are suitable for research on optometry and potential algorithms that may be used in future clinical practice.

The characteristics and medical applications of antler stem cells

Antlers are the only fully regenerable mammalian appendages whose annual renewal is initiated by antler stem cells (ASCs), defined as a specialized type of mesenchymal stem cells (MSCs) with embryonic stem cell properties. ASCs possess the same biological features as MSCs, including the capacity for self-renewal and multidirectional differentiation, immunomodulatory functions, and the maintenance of stem cell characteristics after multiple passages. Several preclinical studies have shown that ASCs exhibit promising potential in wound healing, bone repair, osteoarthritis, anti-tissue fibrosis, anti-aging, and hair regeneration. Medical applications based on ASCs and ASC-derived molecules provide a new source of stem cells and therapeutic modalities for regenerative medicine. This review begins with a brief description of antler regeneration and the role of ASCs. Then, the properties and advantages of ASCs are described. Finally, medical research advances regarding ASCs are summarized, and the prospects and challenges of ASCs are highlighted.

Factors Affecting Intensive Aflibercept Treatment Response in Diabetic Macular Edema: A Real-World Study

Objective

To investigate the systemic and ocular factors that affect the response to intensive aflibercept treatment in diabetic macular edema (DME) in a real-world setting.

Methods

This retrospective cohort study evaluated 30 eyes of 23 patients with DME who underwent intensive intravitreal aflibercept injections (five monthly loading doses). Treatment response was assessed by central retinal thickness (CRT) and best-corrected visual acuity (BCVA) at each monthly visit. The patients were categorized as good (<300 μm) and suboptimal (≥300 μm) responders based on CRT after the loading phase. Baseline systemic and ocular factors associated with treatment response were investigated.

Results

The mean CRT and BCVA significantly improved after five loading injections (486.87 ± 95.46 to 334.90 ± 69.47 μm and 0.51 ± 0.30 to 0.35 ± 0.25 LogMAR, respectively, all p < 0.05). During 12 months of follow-up, 16 eyes (53.33%) maintained CRT without additional treatment. Eyes with diabetes mellitus (DM) for ≥15 years, estimated glomerular filtration rate (eGFR) < 80 mL/min/1.73 m², serum creatinine ≥ 0.95 mg/dL and potassium ≥ 4.7 mmol/L, and presence of epiretinal membrane (ERM) were more likely to have a suboptimal response to the treatment.

Conclusions

Five monthly loading doses of intravitreal aflibercept injection provided significant anatomical and visual improvements in patients with DME. Patients with longer DM duration, lower eGFR, higher serum creatinine or potassium levels, or ERM were predisposed to a suboptimal treatment response. Individual response to intensive aflibercept treatment for DME can be predicted by these systemic and ocular risk factors.

Pro re nata Treatment of Diabetic Macular Edema with Cycles of Three Injections of Anti-vascular Endothelial Growth Factor Injections

PURPOSE

The purpose of this study was to report the visual and anatomic results at 12 and 24 months using the protocol of 3 monthly pro re nata (PRN) injections for diabetic macular edema (DME).

METHODS

This was a retrospective chart review of 97 eyes with DME treated with a protocol of cycles consisting of 3 monthly injections of anti-vascular endothelial growth factor drugs on a PRN basis. Change in visual acuity was the main outcome measure. Macular thickness, number of injections, cycles, and visits in years 1 and 2 of follow-up were secondary outcomes.

RESULTS

Ninety-six patients with a mean age of 60.9 ± 9.96 years were followed for a mean of 22.17 ± 12.30 months. Ninety-two (95.9%), 3 (3%), and 1 (1%) patients were started on bevacizumab, ranibizumab, and aflibercept, respectively. Of bevacizumab patients, 17 (18.2%) were eventually switched to aflibercept. The mean 12-month improvement (standard deviation [SD]) was + 3.3 (17.4) letters (95% confidence interval [CI] = +0.36-+7.05, P < 0.001) after an average (SD) of 5.97 (2.98) injections over a mean (SD) of 1.7 (1.0) three-injection cycles. The mean 24-month improvement (SD) was + 5.6 (13.0) letters (95% CI: -0.28-11.05, P = 0.0186) after an average (SD) of 8.72 (6.31) injections over a mean (SD) of 2.9 (2.1) three-injection cycles. The mean central macular thickness (SD) at baseline, 12 months, and 24 months was 374 ± 120, 322 ± 88, and 305 ± 70 µm. Optical coherence tomography was fluid free at 12 and 24 months in 27.6% and 46% of eyes, respectively.

CONCLUSION

Comparable to real-world studies, this protocol can stabilize or improve vision in more than 85% of DME patients over 24 months. The most important factor in improvement of vision is increasing number of injections and visits.

The effect of hypotensive drugs on intraocular lenses clarity

OBJECTIVES

To assess the effect of hypotensive drugs on light absorbance, discoloration, opacification and precipitate formation of IOLs.

METHODS

In this laboratory study, four types of IOLs (two hydrophilic-acrylic-L1 and L2, and two hydrophobic-acrylic-B1 and B2) were soaked in solutions containing Timolol-maleate 0.5%, Dorzolamide 2%, Brimonidine-tartrate 0.2%, Latanoprost 0.005%, Brimonidine-tartrate/Timolol-maleate 0.2%/0.5% and Dorzolamide/Timolol-maleate 2%/0.5%. Non-treated IOLs and IOLs soaked in balanced salt solution (BSS) served as controls. All Treated lenses were sealed in containers and placed in an oven at 82 degrees Celsius for 120 days. Each IOL was examined using four different techniques: light microscopy imaging, light absorbance measurements at 550 nanometers through the optic's center, assessment of by a scanning electron microscope (SEM), and energy dispersive Xray spectrometry (EDX).

RESULTS

Ninety-eight IOLs were included. All BSS-soaked IOLs appeared clear with no significant discoloration or precipitate-formation. Light absorbance in these lenses was comparable to that of non-soaked, non-heated IOLs. No calcium or phosphate were detected in either of these groups. Light absorbance differed significantly between the four treated IOL types. The drops most affecting light absorbance differed between IOLs. Gross examination revealed brown and yellow discoloration of all IOLs soaked in Dorzolamide and Brimonidine-tartrate solutions, respectively. SEM demonstrated precipitates that differed in size, morphology and distribution, between different IOL-solution combinations. EDX's demonstrated the presence calcium and phosphor in the majority of precipitates and the presence of sulfur in brown discolored IOLs.

CONCLUSIONS

In vitro, interactions between hypotensive drugs and IOLs induce changes in light absorbance, discoloration and precipitate formation.

Wound-Healing Effects of Mesenchymal Stromal Cell Secretome in the Cornea and the Role of Exosomes

Mesenchymal stromal/stem cells (MSCs) and their secreted factors have been shown to have immunomodulatory and regenerative effects. In this study, we investigated human bone-marrow-derived MSC secretome (MSC-S) for the treatment of corneal epithelial wounds. Specifically, we evaluated the role of MSC extracellular vesicles (EV)/exosomes in mediating the wound-healing effects of the MSC-S. In vitro studies using human corneal epithelial cells showed that MSC-CM increased cell proliferation in HCEC and HCLE cells, while EV-depleted MSC-CM showed lower cell proliferation in both cell lines compared to the MSC-CM group. In vitro and in vivo experiments revealed that 1X MSC-S consistently promoted wound healing more effectively than 0.5X MSC-S, and MSC-CM promoted wound healing in a dose-dependent manner, while exosome deprivation delayed wound healing. We further evaluated the incubation period of MSC-CM on corneal wound healing and showed that MSC-S collected for 72 h is more effective than MSC-S collected for 48 h. Finally, we evaluated the stability of MSC-S under different storage conditions and found that after one cycle of freeze-thawing, MSC-S is stable at 4 °C for up to 4 weeks. Collectively, we identified the following: (i) MSC-EV/Exo as the active ingredient in MSC-S that mediates the wound-healing effects in the corneal epithelium, providing a measure to optimize its dosing for a potential clinical product; (ii) Treatment with EV/Exo-containing MSC-S resulted in an improved corneal barrier and decreased corneal haze/edema relative to EV/Exo-depleted MSC-S; (iii) The stability of MSC-CM for up to 4 weeks showed that the regular storage condition did not significantly impact its stability and therapeutic functions.

Antimicrobial resistance profiles and clonal diversity of Staphylococcus epidermidis isolates from pig farms, slaughterhouses, and retail pork

Livestock-associated coagulase-negative staphylococci (CoNS), such as Staphylococcus (S.) epidermidis, have emerged as a significant reservoir of antimicrobial resistance (AMR). In the current study, the AMR profiles and genetic diversity of S. epidermidis isolates obtained from pig farms, slaughterhouses, and retail pork were analyzed. A total of 89 S. epidermidis isolates, comprising 22 methicillin-resistant (MRSE) and 67 methicillin-susceptible S. epidermidis (MSSE) isolates, were assessed to determine (i) the clonal lineages of the isolates [multilocus sequence (MLST), agr, and staphylococcal cassette chromosome mec (SCCmec) types], (ii) the profiles of AMR phenotypes, and (iii) the carriage of genetic factors associated with major AMR phenotypes and zinc chloride resistance. Two dominant clonal lineages of S. epidermidis, ST100 and ST570, were observed on pig farms, especially in healthy pigs. In addition, potential transmission of pig-associated ST100 MRSE-SCCmec V and ST100 MSSE to farm workers was identified. The high prevalence of ST100 and ST570 isolates in pig farms was associated with high levels of AMR and zinc chloride resistance. In relation to resistance phenotypes, higher carriage rates of resistance genes, such as β-lactams (mecA), phenicols (fexA), and tetracyclines [tet(K), tet(L), tet(S), tet(M), and tet(O)], were identified in pig farm-associated isolates. Furthermore, cfr-mediated linezolid resistance was detected in 14 MSSE isolates from pig farms. This study is the first to provide important insights into the clonal structures and AMR profiles of S. epidermidis isolates collected from healthy pigs, carcass/pork samples, and human workers in Korea.

Bilateral endogenous fungal endophthalmitis: A case report

RATIONALE

Endogenous fungal endophthalmitis is a challenging condition. There are no universally accepted diagnostic or management protocols. We share a case of endogenous fungal endophthalmitis who was successfully treated, focusing on the diagnostic and treatment procedures.

PATIENT CONCERNS

A 31-year-old female with a history of fungal vaginitis and tinea corporis presented with progressive visual decrease in both eyes after having an induced abortion. Her best corrected visual acuity at presentation was 20/1000 in her right eye and 20/250 in her left eye. Upon slit lamp examination, mild inflammatory reaction in the anterior chamber was found. Dilated fundus examination revealed a hazy view of the optic disc and posterior retina, and there was a whitish mass with "string and pearls" just in front of the macular region in each eye.

DIAGNOSES

Bilateral fungal endogenous endophthalmitis was diagnosed empirically, which was confirmed later by deoxyribonucleic acid sequencing and culture of intraocular fluid.

INTERVENTIONS

Oral itraconazole and intravitreal voriconazole were administered to the patient at first. The intraocular inflammation was partially responsive to the medication, yet the visual acuity persisted to deteriorate and the vitreous whitish masses became more prominent. Then vitrectomy procedures were carried out and oral itraconazle was switched to intravenous fluconazole. The antifungal treatment lasted for 8 weeks.

OUTCOMES

The intraocular inflammation alleviated and visual acuity improved after vitrectomy. At the 9-month follow-up visit, the patient's best corrected visual acuity was 20/40 in the right eye and 20/30 in the left eye. There was no intraocular inflammatary reaction, and retinal scar was noticed in each eye.

LESSON

Early and correct diagnosis, coupled with prompt and aggressive treatment, is crucial for cases of fungal endogenous endophthalmitis. Deoxyribonucleic acid sequencing techniques can contribute to early diagnosis, while vitrectomy may be necessary when antifungal medication is insufficient in controlling the condition.

Metabolism: How removal of damaged cells impacts energy availability in the retina

Once thought to be a quiescent process, elimination of damaged cells by professional phagocytes is now understood to modulate metabolite availability within tissues. A new study reveals that the retinal pigment epithelium serves as a local source of insulin after engulfment of damaged photoreceptors.

Drug Susceptibility Test and Analysis of Quinolone Resistance Genes in Mycoplasma hyopneumoniae Vaccine Strains and Field Isolates from China

Background

Enrofloxacin is a commonly used animal-specific drug in veterinary clinics. However, this drug has no epidemiological cutoff values (ECVs/ECOFFs) for Mycoplasma hyopneumoniae in CLSI and EUCAST. Defining the epidemiological cutoff values (ECOFFs) of enrofloxacine to Mycoplasma hyopneumoniae (M. hyo) can inform an early detection of bacterial resistance to better manage the resistance prevention and also help in establishing drug resistance breakpoints;.

Methods

We determined the susceptibility breakpoint of M. hyo to enrofloxacin by the American Clinical and Laboratory Standards Institute (CLSI) standard method based on the PCR of vaccine strains and wild strains drug resistance genes;.

Results

Eighty strains of M.hyo isolated in Tibet were moderately sensitive (S) to tetracycline, florfenicol, spiramycin, erythromycin thiocyanate, tilmicosin, tiamulin, lincomycin, clindamycin, ofloxacin, enrofloxacin, gentamicin, amikacin, with MICs below 0.5 μg/mL. For vaccine 168L, RM48, and J strains, the susceptibility to the same antibacterial drugs was lower compared to the Tibetan isolates. The resistance of J strain to erythromycin thiocyanate was confirmed. Gene point mutation was confirmed in Quinolone Resistance Determining Regions (QRDR) of HNSH strain Topoisomerase IV subunit A, this finding is compared with the sequencing results of 168L strain reference sequence (Accession number: CP003131). Arg-Lys amino acid mutation (G921A and G1179A) was confirmed for the increase of MIC value involved in M.hyo to enrofloxacine;.

Conclusion

The cut-off value of M.hyo to enrofloxacin was set as 1 μg/mLby ECOFFinder XL 2010 V2.1.

Clinical Application of Intravitreal Aflibercept Injection for Diabetic Macular Edema Comparing Two Loading Regimens

Background and Objectives: We investigated and compared the efficacy of three and five monthly loading regimens of an intravitreal aflibercept injection (IVA) in patients with diabetic macular edema (DME). Materials and Methods: This was a retrospective study that included patients diagnosed with DME and treated with an either three or five monthly aflibercept loading regimen from July 2018 to March 2022. Information on clinical characteristics and changes in the central retinal thickness (CRT) were obtained from medical records. Results: In total, 44 eyes of 44 patients with DME treated with IVA were included in this study, with 30 eyes treated with 3-monthly loadings (three-loading group) and 14 eyes with 5-monthly loadings (five-loading group). The mean CRT significantly decreased from the baseline one month after loading in both the three-loading and five-loading groups (p < 0.001). Four cases were refractory to treatment in the three-loading group, while there were no cases of refractory DME in the five-loading group. The stability rate was significantly higher in the five-loading group at three months after loading (p = 0.033). Conclusions: Five-monthly loading regimens of IVA might be favorable for DME considering the rate of refractory cases, stable duration, and the importance of early responsiveness to IVA in DME.

Safety and Efficacy of a Treat-and-Extend Regimen of Anti-Vascular Endothelial Growth Factor Agents for Diabetic Macular Edema or Macular Edema Secondary to Retinal Vein Occlusion: A Systematic Review and Meta-Analysis

[Box: see text] Background and Objective: This meta-analysis evaluates treat-and-extend regimens relative to monthly and as-needed (prn) regimens using anti-vascular endothelial growth factor agents for diabetic macular edema and macular edema secondary to retinal vein occlusion.

MATERIALS AND METHODS

Comparative studies evaluating a treat-and-extend regimen relative to a monthly or prn regimen with anti-vascular endothelial growth factor therapy for diabetic macular edema or macular edema secondary to retinal vein occlusion were included following a systematic literature search.

RESULTS

Seven studies of 984 eyes were included. Relative to a monthly regimen, treat-and-extend was similar for change in best-corrected visual acuity at final follow-up (P = .59) and had a lower number of injections (P < .00001). Relative to a prn regimen, treat-and-extend was similar for change in best-corrected visual acuity at final follow-up (P = .84) and was associated with a higher number of injections (P = .02).

CONCLUSION

This meta-analysis found that a treat-and extend regimen was nonsignificantly different compared to monthly and prn regimens in efficacy and safety end points. [Ophthalmic Surg Lasers Imaging Retina 2023;54(3):131-138.].

Separate lifetime signatures of macaque S cones, M/L cones, and rods observed with adaptive optics fluorescence lifetime ophthalmoscopy

In the retina, several molecules involved in metabolism, the visual cycle, and other roles exhibit intrinsic fluorescence. The overall properties of retinal fluorescence depend on changes to the composition of these molecules and their environmental interactions due to transient functional shifts, especially in disease. This behooves the understanding of the origins and deviations of these properties within the multilayered retina at high lateral and axial resolution. Of particular interest is the fluorescence lifetime, a potential biomarker of function and disease independent of fluorescence intensity that can be measured in the retina with adaptive optics fluorescence lifetime ophthalmoscopy (AOFLIO). This work demonstrates the utility of the phasor method of analysis, an alternate approach to traditional multiexponential fitting, to evaluate photoreceptor two-photon excited AOFLIO data and separate them based on functional differences. Phasor analysis on fluorescence lifetime decay data allowed the repeatable segregation of S from M/L cones, likely from differences in functional or metabolic demands. Furthermore, it is possible to track the lifetime changes in S cones after photodamage. Phasor analysis increases the sensitivity of AOFLIO to functional differences between cells and has the potential to improve our understanding of pathways involved in normal and diseased conditions at the cellular scale throughout the retina.

Phagocytosis in the retina promotes local insulin production in the eye

The retina is highly metabolically active, relying on glucose uptake and aerobic glycolysis. Situated in close contact to photoreceptors, a key function of cells in the retinal pigment epithelium (RPE) is phagocytosis of damaged photoreceptor outer segments (POS). Here we identify RPE as a local source of insulin in the eye that is stimulated by POS phagocytosis. We show that Ins2 messenger RNA and insulin protein are produced by RPE cells and that this production correlates with RPE phagocytosis of POS. Genetic deletion of phagocytic receptors ('loss of function') reduces Ins2, whereas increasing the levels of the phagocytic receptor MerTK ('gain of function') increases Ins2 production in male mice. Contrary to pancreas-derived systemic insulin, RPE-derived local insulin is stimulated during starvation, which also increases RPE phagocytosis. Global or RPE-specific Ins2 gene deletion decreases retinal glucose uptake in starved male mice, dysregulates retinal physiology, causes defects in phototransduction and exacerbates photoreceptor loss in a mouse model of retinitis pigmentosa. Collectively, these data identify RPE cells as a phagocytosis-induced local source of insulin in the retina, with the potential to influence retinal physiology and disease.

Treat and extend regimen for diabetic macular oedema-a systematic review and meta-analysis

PURPOSE

Various treatment regimens are currently practiced in the treatment of CI-DMO (centre-involving diabetic macular oedema). In recent years, there has been a growing body of evidence supporting a treat and extend (T&E) regimen for DMO which offers the promise of comparable visual and anatomical outcomes while reducing injection burden. This meta-analysis was hence performed to evaluate the aforementioned outcomes in the treatment of DMO. Ten studies met the inclusion criteria.

METHODS

A search of PubMed, MEDLINE, Current Contents, and Cochrane Central Register of Controlled Trials (CENTRAL) databases was performed. We employed the terms 'treat AND extend AND (diabetic AND macular AND edema OR oedema)' to ensure a comprehensive search. The search workflow adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

The pooled analysis of the mean number of injections in 1 year for T&E-aflibercept (AFL), T&E-ranibizumab (RBZ) and collectively was 9.1 (95% CI: 7.63-10.63), 10.0 (95% CI: 9.55-10.47) and 9.6 (95% CI: 8.62-10.49), respectively. Improvements in vision at 1 year for T&E-AFL, T&E-RBZ and collectively were 6.26 (95% CI: 3.24-9.29), 7.14 (95% CI: 4.76-9.52) and 7.08 (95% CI: 5.32-8.84) letters, respectively. The improvements in central subfield thickness at 1 year for T&E-AFL, T&E-RBZ and collectively were 131.94 (95% CI: 100.29-163.60), 108.64 (95% CI: 82.82-134.46) and 121.32 (95% CI: 102.89-139.75) microns, respectively.

CONCLUSION

The meta-analysis of T&E for DMO did not show a clear advantage in reducing the number of injections compared to landmark clinical trials with pro-re-nata (PRN) treatment regimens in the first year of treatment with limited gains in visual and anatomical outcomes. However, the T&E approach offers the potential for fewer patient visits, thereby reducing treatment burden. Longer term studies on T&E with a standardised protocol would be required to assess the longevity of the vision gain in the first year despite a likely reduced treatment burden compared to the PRN trials.

Evaluating the Treatment of Diabetic Macular Edema with Aflibercept Based on a Regional Network of Ophthalmologic Care Givers

Purpose

In Austria, anti-VEGF therapies are reimbursed only in clinical settings. This study aimed to describe the outcome of a treat and extend regimen (TER) with aflibercept for diabetic macular edema (DME) in a network of practitioners.

Methods

In a prospective study over 36 months, patients with DME were treated with a loading dose of aflibercept and further on with adjusted treatment intervals based on optical coherence tomography (OCT) findings. All patients were monitored in an outpatient setting by regional ophthalmologists, and the treatment was administered in the clinic. Main outcome parameters were best-corrected visual acuity (BCVA) from baseline to the last regular visit. Number of visits at the practitioner's office as well as the number of injections were secondary outcome parameters.

Results

Thirty-three patients completed the study at their final visit. BCVA improved significantly by 5.8 letters between baseline and the final visit from 70.4 letters at baseline (p=0.004). Patients visited the practitioner's office 12.8 times in the observation period of 36 months. 3.7, 5.1, and 3.9 visits were performed, respectively, in the first, second, and third years, and 25.5 ± 7.9 injections were performed. The mean interval of injections over the observation period was 6.2 ± 2.2 in weeks.

Conclusion

The treat and extend regimen was valuable for treating patients with DME in this specific setting. The functional results of this study were comparable to those of other real-world evaluations. Adherence to the same treating institution seems to be important to avoid differences in therapeutic decision making and may also increase patient's compliance.

Gene-agnostic therapeutic approaches for inherited retinal degenerations

Inherited retinal diseases (IRDs) are associated with mutations in over 250 genes and represent a major cause of irreversible blindness worldwide. While gene augmentation or gene editing therapies could address the underlying genetic mutations in a small subset of patients, their utility remains limited by the great genetic heterogeneity of IRDs and the costs of developing individualised therapies. Gene-agnostic therapeutic approaches target common pathogenic pathways that drive retinal degeneration or provide functional rescue of vision independent of the genetic cause, thus offering potential clinical benefits to all IRD patients. Here, we review the key gene-agnostic approaches, including retinal cell reprogramming and replacement, neurotrophic support, immune modulation and optogenetics. The relative benefits and limitations of these strategies and the timing of clinical interventions are discussed.

Delayed Bacterial Endotheliitis and Endophthalmitis 11 Years after Cataract Surgery

Infective endophthalmitis is an uncommon complication following intraocular surgery. Chronic endophthalmitis may present some time after intraocular surgery, making the diagnosis challenging. Cutibacterium acnes is a well-recognised causative agent of these chronic infections. Practitioners should be aware of the conditions required to culture this slow-growing organism. We report a case of delayed low-grade endophthalmitis presenting 11 years after cataract surgery. Cutibacterium acnes and Staphylococcus warneri were cultured from Descemet's membrane biopsy following three failed previous attempts at microbiological studies. Clinical features of the infection included discrete white granules on the iris, endothelium, and within the capsular bag of the patient's right eye. The patient presented with no signs of systemic infection and the left eye was normal on examination. Bullous keratopathy, secondary to endothelial dysfunction was a feature of this infection. This retrospective case report illustrates the prolonged periods for which Cutibacterium acnes can remain latent before causing clinical signs. While uncommon, endothelial involvement may occur and clinicians should consider low-grade infective endophthalmitis in cases with corneal oedema.

Diabetic Retinopathy – Diagnostics and Treatment Guidelines

Diabetic retinopathy is one of the most common complications of diabetes mellitus and represents a serious health, social and economic problem. With the expected increase in the number of patients with diabetes, it is becoming the leading cause of severe vision loss in the working-age population.  The presented guidelines summarize the current knowledge about this disease in order to standardize and update the procedures for the diagnosis, classification and treatment of diabetic retinopathy.

Advances in artificial intelligence models and algorithms in the field of optometry

The rapid development of computer science over the past few decades has led to unprecedented progress in the field of artificial intelligence (AI). Its wide application in ophthalmology, especially image processing and data analysis, is particularly extensive and its performance excellent. In recent years, AI has been increasingly applied in optometry with remarkable results. This review is a summary of the application progress of different AI models and algorithms used in optometry (for problems such as myopia, strabismus, amblyopia, keratoconus, and intraocular lens) and includes a discussion of the limitations and challenges associated with its application in this field.

[Corneal regeneration: is there a place for tissues of perinatal origin?]

The article reviews the main properties of the cornea and the mechanisms of its physiological regeneration and repair in response to damage and describes the most promising methods of treatment aimed at stimulating limbal stem cells and based on the use of native tissues of perinatal origin, umbilical cord mesenchymal stromal cells, and cell-free therapeutic products.

Antimicrobial resistance and molecular typing of Salmonella in the chicken production chain in Hubei Province, China

Salmonella is a significant foodborne zoonotic pathogen that endangers both human and animal health. The goal of this research is to gain a preliminary understanding of Salmonella contamination and antimicrobial resistance in the chicken production chain in Hubei Province, China. 1149 animal and environmental samples were collected from chicken farms, slaughterhouses, and retail markets in six cities across Hubei Province in China from 2019 to 2020, yielding Salmonella isolation rates of 4.68% (28/598), 12.21% (47/385), and 9.64% (16/166), respectively. Seventeen distinct serotypes were detected among 53 non-clonal Salmonella strains, of which Meleagridis (26.42%, 14/53) was the dominant serotype. Almost half of the strains (49.06%, 26/53) were multi-drug resistant (MDR). Whole-genome sequencing (WGS) showed that 10 resistance genes (tetA, blaTEM, parC, qnrS1, floR, aac(6′)-Iy, aph(6)-Id, aph(3″)-Ib, aac(6′)-Iaa and sul2) and 7 categories of virulence genes were present in all three links in 22 non-clonal dominant serotype strains. It was shown that Salmonella in the chicken production chain in Hubei Province had a high resistance rate to Tetracycline (TET, 73.58%), Ofloxacin (OFL, 69.81%), Florfenicol (FFC, 60.38%) and Ampicillin (AMP, 39.62%) which was consistent with the widespread use of these drugs in the husbandry industry in China. Salmonella ST types determined by MLST and serotypes determined by WGS had a one-to-one correlation. Minimum spanning tree analysis revealed that there was cross contamination of Salmonella in farms and slaughterhouses, slaughterhouses and markets, animal samples and environmental samples. This work provides useful information for the prevention and control of contamination and antimicrobial resistance of Salmonella in the chicken production chain, as well as demonstrating the dependable role of WGS in Salmonella molecular typing.

Effect of Secretome-Hypoxia Mesenchymal Stem Cells on Regulating SOD and MMP-1 mRNA Expressions in Skin Hyperpigmentation Rats

BACKGROUND: Ultraviolet B (UVB) radiation is the main factor causing hyperpigmentation. MSC secretome contains bioactive soluble molecules such as cytokines and growth factors that can accelerate skin regeneration. However, the molecular role of the secretome in hyperpigmentation is still unclear. AIM: This study aimed to determine the effect of secretome hypoxia mesenchymal stem cells (S-HMSC) gel on the expression of superoxide dismutase (SOD) and matrix metalloproteinases (MMP-1) genes in skin tissue of hyperpigmented rats induced by UVB light exposure. MATERIALS AND METHODS: Experimental research with post-test only control group. The control, base gel, T1 and T2 groups were UVB irradiated 6 times in 14 days at 302 nm with an minimal erythema dose of 390 mJ/cm2, respectively, while sham group did not receive UVB exposure. T1 was given 100 uL of S-HMSC gel and T2 was given 200 uL of S-HMSC gel every day for 14 days, while base gel received base gel. On day 15, skin tissue was isolated and analyzed for SOD and MMP-1 expression using qRT-PCR. RESULTS: The relative expression of the SOD gene in the treatment group (P1 = 0.47 ± 0.20, P2 = 1.22 ± 0.47) increased with increasing dose compared to the control group (UVB = 0.05 ± 0.01, Base gel = 0.05 ± 0.02). The relative expression of the MMP-1 gene in the treatment group (T1 = 5.82 ± 1.16, T2 = 2.86 ± 1.57) decreased with increasing dose compared to the control group (Control = 10.10 ± 2.31, and Base gel = 9.55 ± 1.29). CONCLUSION: Administration of S-HMSC gel can increase SOD gene expression and decrease MMP-1 gene expression in skin tissue of hyperpigmented rats model induced by UVB light.

Overexpression of Rhodopsin or Its Mutants Leads to Energy Metabolism Dysfunction in 661w Cells

Purpose

Retinitis pigmentosa (RP) is a heterogeneous group of inherited disorders characterized by photoreceptor degeneration. The rhodopsin gene (RHO) is the most frequent cause of autosomal dominant RP (ADRP), yet it remains unclear how RHO mutations cause heterogeneous phenotypes. Energy failure is a main cause of the secondary cone death during RP progression; however, its role in primary rod death induced by ADRP RHO mutants is unknown.

Methods

Three RHO missense mutations were chosen from different clinical classes. Wild-type (WT) RHO and its mutants, P23H (class B1), R135L (class A), and G188R (class B2), were overexpressed in 661w cells, a mouse photoreceptor cell line, and their effects on oxidative phosphorylation (OXPHOS) and aerobic glycolysis were compared separately.

Results

Here, we report that energy failure is an early event in the cell death caused by overexpression of WT RHO and its mutants. RHO overexpression leads to OXPHOS deficiency, which might be a result of mitochondrial loss. Nonetheless, only in WT RHO and P23H groups, energy stress triggers AMP-activated protein kinase activation and metabolic reprogramming to increase glycolysis. Metabolic reprogramming impairment in R135L and G188R groups might be the reason why energy failure and cell injury are much more severe in those groups.

Conclusions

Our results imply that overexpression of RHO missense mutants have distinct impacts on the two energy metabolic pathways, which might be related to their heterogeneous phenotypes.

Clinical characteristics and risk factors for visual prognosis according to the types of infectious endophthalmitis

BACKGROUND

Endophthalmitis is a fatal ophthalmological emergency that needs prompt diagnosis and treatment. This study aimed to evaluate the clinical characteristics and investigate risk factors for the visual prognosis of the different types of endophthalmitis.

METHODS

This retrospective study included 239 eyes diagnosed with endophthalmitis at the Pusan National University Hospital between January 2006 and December 2020. All patients were classified into six groups based on the etiology of endophthalmitis: post-cataract surgery, post-vitrectomy, post-glaucoma surgery, post-intravitreal injection, endogenous, and post-trauma. Demographics and clinical characteristics such as age, sex, laterality, initial symptoms, the interval between the primary causable event and diagnosis of endophthalmitis, initial and final visual acuity, management, and culture results were reviewed and statistically analyzed. Risk factors for poor visual prognosis were also analyzed according to the type of endophthalmitis.

RESULTS

Of the 239 cases of endophthalmitis, the most common cause was post-cataract surgery, that occurs within two weeks post-surgery. Gram-positive Staphylococcus was cultured most frequently. Fusarium was characteristically cultured from delayed post-cataract surgery endophthalmitis (14 days-6 weeks post-surgery). Post-vitrectomy endophthalmitis occurred within 3.3 days post-surgery, but post-glaucoma surgery endophthalmitis developed a long period after surgery, averaging 2,742 days. Post-intravitreal injection endophthalmitis occurred most frequently following bevacizumab injection, and Staphylococcus was most commonly isolated. For endogenous endophthalmitis, the pyogenic liver abscess was the most common underlying disease, and Klebsiella was isolated most frequently. Post-traumatic endophthalmitis mostly occurred in young men. Advanced age and poor initial visual acuity were risk factors for poor visual prognosis (P = 0.041, odds ratio = 1.024 and P < 0.001, odds ratio = 3.904, respectively, using logistic regression analysis).

CONCLUSION

Advanced age and initial visual acuity were risk factors for poor visual prognosis in cases of endophthalmitis caused by various etiologies. Early diagnosis and treatment of endophthalmitis are required, especially in older patients.

Dissecting Regulators of Aging and Age-Related Macular Degeneration in the Retinal Pigment Epithelium

Age-related macular degeneration (AMD), the leading cause of blindness in elderly populations, involves the loss of central vision due to progressive dysfunction of the retinal pigment epithelium (RPE) and subsequent loss of light-sensing photoreceptors. While age is a key risk factor, not every aged individual develops AMD. Thus, the critical question is what specific cellular changes tip the balance from healthy aging to disease. To distinguish between changes associated with aging and AMD, we compared the RPE proteome in human eye bank tissue from nondiseased donors during aging (n = 50, 29-91 years) and in donors with AMD (n = 36) compared to age-matched donors without disease (n = 28). Proteins from RPE cells were separated on two-dimensional gels, analyzed for content, and identified using mass spectrometry. A total of 58 proteins displayed significantly altered content with either aging or AMD. Proteins involved in metabolism, protein turnover, stress response, and cell death were altered with both aging and AMD. However, the direction of change was predominantly opposite. With aging, we detected an overall decrease in metabolism and reductions in stress-associated proteins, proteases, and chaperones. With AMD, we observed upregulation of metabolic proteins involved in glycolysis, TCA, and fatty acid metabolism, with a concurrent decline in oxidative phosphorylation, suggesting a reprogramming of energy utilization. Additionally, we detected upregulation of proteins involved in the stress response and protein turnover. Predicted upstream regulators also showed divergent results, with inhibition of inflammation and immune response with aging and activation of these processes with AMD. Our results support the idea that AMD is not simply advanced aging but rather the culmination of perturbed protein homeostasis, defective bioenergetics, and increased oxidative stress within the aging RPE, exacerbated by environmental factors and the genetic background of an individual.

Neuroinflammation in retinitis pigmentosa: Therapies targeting the innate immune system

Retinitis pigmentosa (RP) is an important cause of irreversible blindness worldwide and lacks effective treatment strategies. Although mutations are the primary cause of RP, research over the past decades has shown that neuroinflammation is an important cause of RP progression. Due to the abnormal activation of immunity, continuous sterile inflammation results in neuron loss and structural destruction. Therapies targeting inflammation have shown their potential to attenuate photoreceptor degeneration in preclinical models. Regardless of variations in genetic background, inflammatory modulation is emerging as an important role in the treatment of RP. We summarize the evidence for the role of inflammation in RP and mention therapeutic strategies where available, focusing on the modulation of innate immune signals, including TNFα signaling, TLR signaling, NLRP3 inflammasome activation, chemokine signaling and JAK/STAT signaling. In addition, we describe epigenetic regulation, the gut microbiome and herbal agents as prospective treatment strategies for RP in recent advances.

Evaluation of the effect of gentamicin in surgical perfusion solution on cataract postoperative endophthalmitis

Objective

To evaluate the effect of gentamicin in surgical perfusion solution on endophthalmitis incidence after cataract surgery.

Methods

A retrospective analysis of endophthalmitis incidence was conducted in two groups of patients who underwent cataract surgery, with (Group B) or without gentamicin (Group A) in the surgical perfusion solution. Endophthalmitis incidence, the isolated pathogenic bacteria strains and their antibiotic sensitivity, and the drug-resistant genotype of the pathogens were examined.

Results

The incidence of endophthalmitis in patients of group A was 0.8‰. Thirteen pathogenic bacterial strains were isolated from the patient samples in group A, including 8 strains of Staphylococcus epidermidis, 1 Staphylococcus aureus, 1 Streptococcus pneumoniae, 1 Streptococcus bovis, 1 Enterococcus faecium and 1 Morganella sp. The incidence of endophthalmitis in group B patients was 0.2‰, which was significantly lower than that in group A (P<0.05). Five strains of pathogenic bacteria were successfully isolated, including 2 strains of Enterococcus faecium, 1 Enterococcus faecalis, 1 Staphylococcus epidermidis and 1 Staphylococcus aureus. There was no significant difference in the proportion of Staphylococcus strains in all isolated bacteria between the two groups (P > 0.05). However, the proportion of Enterococci isolated in group B samples was higher than that in group A (P < 0.05). There were more gentamicin-sensitive strains than levofloxacin-sensitive strains identified (P < 0.05). Interestingly, aminoglycoside-inactivating enzyme resistance gene was detected in Enterococcus strains.

Conclusion

Our data suggest that gentamicin-containing perfusion solution can reduce the incidence of postoperative endophthalmitis in cataract patients. However, the selective pressure imposed by gentamicin may facilitate the development of aminoglycoside-resistant Enterococcos strains.

Highlighting the Microbial Contamination of the Dropper Tip and Cap of In-Use Eye Drops, the Associated Contributory Factors, and the Risk of Infection: A Past-30-Years Literature Review

The sterility of eye drop content is a primary concern from manufacturing until opening, as well as during handling by end users, while microbial contamination of the dropper tip and cap are often disregarded. The contamination of these sites during drug administration represents a risk of microbial transmission and ocular infection. In this review, we aim to assess microbial contamination of the dropper tip and cap of in-use eye drops, the associated contributory factors, and the risk of infection. We conducted a literature search of the MEDLINE, PubMed, and Cochrane Central databases. A total of 31 out of 1503 studies were selected. All the studies conducted in different settings that documented microbiologically contaminated in-use eye drops were included. Our review showed that microbial contamination of the dropper tip and cap of in-use eye drops ranged from 7.7 to 100% of the total contaminated tested samples. Documented contributory factors were conflicting across the literature. Studies investigating the association between eye infection and microbial contamination of the dropper tip and cap were scarce. New technologies offer a promising potential for securing the long-term sterility of eye drop content, tips, and caps, which could benefit from more research and well-defined study protocols under real-life scenarios.

Cellular and molecular alterations in neurons and glial cells in inherited retinal degeneration

Multiple gene mutations have been associated with inherited retinal dystrophies (IRDs). Despite the spectrum of phenotypes caused by the distinct mutations, IRDs display common physiopathology features. Cell death is accompanied by inflammation and oxidative stress. The vertebrate retina has several attributes that make this tissue vulnerable to oxidative and nitrosative imbalance. The high energy demands and active metabolism in retinal cells, as well as their continuous exposure to high oxygen levels and light-induced stress, reveal the importance of tightly regulated homeostatic processes to maintain retinal function, which are compromised in pathological conditions. In addition, the subsequent microglial activation and gliosis, which triggers the secretion of pro-inflammatory cytokines, chemokines, trophic factors, and other molecules, further worsen the degenerative process. As the disease evolves, retinal cells change their morphology and function. In disease stages where photoreceptors are lost, the remaining neurons of the retina to preserve their function seek out for new synaptic partners, which leads to a cascade of morphological alterations in retinal cells that results in a complete remodeling of the tissue. In this review, we describe important molecular and morphological changes in retinal cells that occur in response to oxidative stress and the inflammatory processes underlying IRDs.

Expert Panel Consensus for Addressing Anti-VEGF Treatment Challenges of Diabetic Macular Edema in Spain

Purpose

The treatment of diabetic macular edema (DME) has evolved rapidly in the past decade, highlighting the need to address the challenges of routine clinical practice decision-making through expert consensus agreements.

Methods

After a literature review and discussion of real-world experience on DME management, a group of ten retina specialists agreed on a consensus of recommendations for the most appropriate management of DME patients using vascular endothelial growth factor inhibitors (anti-VEGF) in Spain.

Results

The panel recommended early treatment initiation in DME patients with worse baseline visual acuity (VA) to maintain or improve outcome. For patients with good VA, an observation strategy was recommended, considering the presence of diabetic retinopathy, optical coherence tomography biomarkers, and impact on patient's quality of life. Based on the available evidence and clinical experience, the panel recommended the use of anti-VEGF intensive loading doses with the objective of achieving anatomic and visual responses as soon as possible, followed by a Treat & Extend (T&E) strategy to maintain VA improvement. Aflibercept was recommended for patients with a baseline decimal VA <0.5, followed by a T&E strategy, including the possibility to extend frequency of injections up to 16 weeks.

Conclusion

An expert panel proposes a consensus for the management of DME in Spain. Early treatment initiation with anti-VEGF in DME patients is recommended to maintain or improve VA; aflibercept is recommended for patients with a poor baseline VA.

The Role of Silicone Oil in the Surgical Management of Endophthalmitis: A Systematic Review

(1) Background: We aimed to systematically review the current literature to evaluate if in patients with postoperative endophthalmitis treated with pars plana vitrectomy, silicone oil tamponade could provide a useful contribution to the control and eradication of infection and if it could influence anatomical recovery and functional outcome. (2) Randomized controlled trials, cross-sectional studies, case series, and case reports published in the English language in peer-reviewed journals were included. No restriction was placed based on the study location. We used medical subject headings (MeSH) and text words. We searched MEDLINE (OVID and PubMed), Google Scholar, ISI Web of Science (Thom-on-Reuters), and the Cochrane Library (Wiley) from January 1995 to the present. To ensure literature saturation, we scanned the reference lists of included studies or relevant reviews identified through the search. Risk of Bias was assessed using the Newcastle-Ottawa scale for longitudinal studies and Cochrane risk-of-bias tool for randomized trials. (3) Results: abstracts of 75 articles were selected for full-text reading; after full-text reading, 44 articles were taken into consideration in the systematic review. 5 out of 7 in vitro experimental studies demonstrated antimicrobial activity against different species of bacteria and fungi. The use of SO as endotamponade associated with PPV led to better visual acuity and a lower rate of retinal detachment and the need for additional surgery. (4) Conclusions: Silicone oil reduces the risk of postoperative retinal detachment, especially in case of undetected retinal breaks, produces compartmentalization of the eye, may lead to early visual recovery, allows laser photocoagulation, prevents severe postoperative hypotony and has antimicrobic activity due to an inhibitory effect for several species of pathogens. Concerns regarding possible toxic effects on the retina and optic disc, compartmentalization and impaired washout of pathogen toxins have been reported. It may also influence intravitreal antibiotic distribution and clearance.

Drug Discovery Strategies for Inherited Retinal Degenerations

Inherited retinal degeneration is a group of blinding disorders afflicting more than 1 in 4000 worldwide. These disorders frequently cause the death of photoreceptor cells or retinal ganglion cells. In a subset of these disorders, photoreceptor cell death is a secondary consequence of retinal pigment epithelial cell dysfunction or degeneration. This manuscript reviews current efforts in identifying targets and developing small molecule-based therapies for these devastating neuronal degenerations, for which no cures exist. Photoreceptors and retinal ganglion cells are metabolically demanding owing to their unique structures and functional properties. Modulations of metabolic pathways, which are disrupted in most inherited retinal degenerations, serve as promising therapeutic strategies. In monogenic disorders, great insights were previously obtained regarding targets associated with the defective pathways, including phototransduction, visual cycle, and mitophagy. In addition to these target-based drug discoveries, we will discuss how phenotypic screening can be harnessed to discover beneficial molecules without prior knowledge of their mechanisms of action. Because of major anatomical and biological differences, it has frequently been challenging to model human inherited retinal degeneration conditions using small animals such as rodents. Recent advances in stem cell-based techniques are opening new avenues to obtain pure populations of human retinal ganglion cells and retinal organoids with photoreceptor cells. We will discuss concurrent ideas of utilizing stem-cell-based disease models for drug discovery and preclinical development.

Research Progress on Preparation, Mechanism, and Clinical Application of Nanofat

Autologous adipose tissue is an ideal soft tissue filling material in theory, which has the advantages of easy access, comprehensive source, and high biocompatibility and is now widely used in clinical practice. Based on the above benefits of autologous fat, autologous fat grafting is an essential technique in plastic surgery. Conventional macrofat is used to improve structural changes after soft tissue damage or loss caused by various causes such as disease, trauma, or aging. Due to the large diameter of particles and to avoid serious complications such as fat embolism, blunt needles with larger diameters (2 mm) are required, making the macrofat grafting difficult to the deep dermis and subdermis. Nanofat grafting is a relatively new technology that has gained popularity in cosmetic surgery in recent years. Nanofat is produced by mechanical shuffling and filtration of microfat, which is harvested by liposuction. The harvesting and processing of nanofat are cost-effective as it does not require additional equipment or culture time. Unlike microfat, nanofat particles are too small to provide a notable volumizing effect. Studies have shown that nanofat contains abundant stromal vascular fraction cells and adipose-derived stem cells, which help reconstruct dermal support structures, such as collagen, and regenerate healthier, younger-looking skin. Moreover, the fluid consistency of nanofat allows application in tissue regeneration, such as scars, chronic wounds, and facial rejuvenation. This article reviews the current research progress on the preparation, mechanism, and clinical application of nanofat.

Corneal Regeneration Using Adipose-Derived Mesenchymal Stem Cells

Adipose-derived stem cells are a subtype of mesenchymal stem cell that offers the important advantage of being easily obtained (in an autologous manner) from low invasive procedures, rendering a high number of multipotent stem cells with the potential to differentiate into several cellular lineages, to show immunomodulatory properties, and to promote tissue regeneration by a paracrine action through the secretion of extracellular vesicles containing trophic factors. This secretome is currently being investigated as a potential source for a cell-free based regenerative therapy for human tissues, which would significantly reduce the involved costs, risks and law regulations, allowing for a broader application in real clinical practice. In the current article, we will review the existing preclinical and human clinical evidence regarding the use of such adipose-derived mesenchymal stem cells for the regeneration of the three main layers of the human cornea: the epithelium (derived from the surface ectoderm), the stroma (derived from the neural crest mesenchyme), and the endothelium (derived from the neural crest cells).

Current Trends in Clinical Characteristics, Diagnosis, and Treatment of Polypoidal Choroidal Vasculopathy: A Perspective from Vietnam

Polypoidal choroidal vasculopathy (PCV) is a common choroidal disease in the Asian population including Vietnam and is characterized by subretinal red-orange nodules, pigmented epithelium detachment, and massive subretinal hemorrhage. The recent focus on PCV in Vietnam can be attributed to advancements in PCV diagnosis and treatment. However, there is a scarcity of published literature and clinical data on PCV in the Vietnamese population, highlighting a key knowledge gap in this region. In order to address this gap, we gathered the opinions of experienced clinicians and retinal experts in Vietnam and reviewed available medical literature with the aim of: (i) providing an overview of PCV in the Vietnamese population—in terms of epidemiology, clinical characteristics, and management; (ii) tailoring international/national guidelines for the diagnosis and management of PCV, in line with available resources and medical equipment in Vietnam; and (iii) identifying gaps in clinical data in order to guide future PCV research in Vietnam and other countries with similar clinical conditions. The present review will enable healthcare providers and researchers to gain insight into current clinical practices and the limitations of PCV management in Vietnam and provide optimal and effective solutions.

Gene Therapy for Rhodopsin Mutations

Mutations in RHO, the gene for rhodopsin, account for a large fraction of autosomal-dominant retinitis pigmentosa (adRP). Patients fall into two clinical classes, those with early onset, pan retinal photoreceptor degeneration, and those who experience slowly progressive disease. The latter class of patients are candidates for photoreceptor-directed gene therapy, while former may be candidates for delivery of light-responsive proteins to interneurons or retinal ganglion cells. Gene therapy for RHO adRP may be targeted to the mutant gene at the DNA or RNA level, while other therapies preserve the viability of photoreceptors without addressing the underlying mutation. Correcting the RHO gene and replacing the mutant RNA show promise in animal models, while sustaining viable photoreceptors has the potential to delay the loss of central vision and may preserve photoreceptors for gene-directed treatments.

An improved strabismus screening method with combination of meta-learning and image processing under data scarcity

Purpose

Considering the scarcity of normal and strabismic images, this study proposed a method that combines a meta-learning approach with image processing methods to improve the classification accuracy when meta-learning alone is used for screening strabismus.

Methods

The meta-learning approach was first pre-trained on a public dataset to obtain a well-generalized embedding network to extract distinctive features of images. On the other hand, the image processing methods were used to extract the position features of eye regions (e.g., iris position, corneal light reflex) as supplementary features to the distinctive features. Afterward, principal component analysis was applied to reduce the dimensionality of distinctive features for integration with low-dimensional supplementary features. The integrated features were then used to train a support vector machine classifier for performing strabismus screening. Sixty images (30 normal and 30 strabismus) were used to verify the effectiveness of the proposed method, and its classification performance was assessed by computing the accuracy, specificity, and sensitivity through 5,000 experiments.

Results

The proposed method achieved a classification accuracy of 0.805 with a sensitivity (correct classification of strabismus) of 0.768 and a specificity (correct classification of normal) of 0.842, whereas the classification accuracy of using meta-learning alone was 0.709 with a sensitivity of 0.740 and a specificity of 0.678.

Conclusion

The proposed strabismus screening method achieved promising classification accuracy and gained significant accuracy improvement over using meta-learning alone under data scarcity.

Glucose uptake by GLUT1 in photoreceptors is essential for outer segment renewal and rod photoreceptor survival

Photoreceptors consume glucose supplied by the choriocapillaris to support phototransduction and outer segment (OS) renewal. Reduced glucose supply underlies photoreceptor cell death in inherited retinal degeneration and age-related retinal disease. We have previously shown that restricting glucose transport into the outer retina by conditional deletion of Slc2a1 encoding GLUT1 resulted in photoreceptor loss and impaired OS renewal. However, retinal neurons, glia, and the retinal pigment epithelium play specialized, synergistic roles in metabolite supply and exchange, and the cell-specific map of glucose uptake and utilization in the retina is incomplete. In these studies, we conditionally deleted Slc2a1 in a pan-retinal or rod-specific manner to better understand how glucose is utilized in the retina. Using non-invasive ocular imaging, electroretinography, and histochemical and biochemical analyses we show that genetic deletion of Slc2a1 from retinal neurons and Müller glia results in reduced OS growth and progressive rod but not cone photoreceptor cell death. Rhodopsin levels were severely decreased even at postnatal day 20 when OS length was relatively normal. Arrestin levels were not changed suggesting that glucose uptake is required to synthesize membrane glycoproteins. Rod-specific deletion of Slc2a1 resulted in similar changes in OS length and rod photoreceptor cell death. These studies demonstrate that glucose is an essential carbon source for rod photoreceptor cell OS maintenance and viability.

Mesenchymal stem cells-derived small extracellular vesicles alleviate diabetic retinopathy by delivering NEDD4

Background

As a leading cause of vision decline and severe blindness in adults, diabetic retinopathy (DR) is characterized by the aggravation of retinal oxidative stress and apoptosis in the early stage. Emerging studies reveal that mesenchymal stem cells-derived small extracellular vesicles (MSC-sEV) treatment represents a promising cell-free approach to alleviate ocular disorders. However, the repairing effects of MSC-sEV in DR remain largely unclear. This study aimed at exploring the role and the underlying mechanism of MSC-sEV in hyperglycemia-induced retinal degeneration.

Methods

In vivo, we used streptozotocin (STZ) to establish diabetic rat model, followed by the intravitreal injection of MSC-sEV to determine the curative effect. The cell viability and antioxidant capacity of retinal pigment epithelium (RPE) cells stimulated with high-glucose (HG) medium after MSC-sEV treatment were analyzed in vitro. By detecting the response of cell signaling pathways in MSC-sEV-treated RPE cells, we explored the functional mechanism of MSC-sEV. Mass spectrometry was performed to reveal the bioactive protein which mediated the role of MSC-sEV.

Results

The intravitreal injection of MSC-sEV elicited antioxidant effects and counteracted retinal apoptosis in STZ-induced DR rat model. MSC-sEV treatment also reduced the oxidative level and enhanced the proliferation ability of RPE cells cultured in HG conditions in vitro. Further studies showed that the increased level of phosphatase and tensin homolog (PTEN) inhibited AKT phosphorylation and nuclear factor erythroid 2-related factor 2 (NRF2) expression in RPE cells stimulated with HG medium, which could be reversed by MSC-sEV intervention. Through mass spectrometry, we illustrated that MSC-sEV-delivered neuronal precursor cell-expressed developmentally downregulated 4 (NEDD4) could cause PTEN ubiquitination and degradation, activate AKT signaling and upregulate NRF2 level to prevent DR progress. Moreover, NEDD4 knockdown impaired MSC-sEV-mediated retinal therapeutic effects.

Conclusions

Our findings indicated that MSC-sEV ameliorated DR through NEDD4-induced regulation on PTEN/AKT/NRF2 signaling pathway, thus revealing the efficiency and mechanism of MSC-sEV-based retinal protection and providing new insights into the treatment of DR.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02983-0.