Filling-the-gap-with-newfound-techniques

 

Denver, Colo.—Four studies presented this week at the Association for Research in Vision and Ophthalmology’s (ARVO) 2022 Annual Meeting in Denver, Colo. highlight the ferocity of the immune system and how one size does not fit all, that researchers must be willing to examine all the unknowns and leave no stone unturned. One study revealed that annual targeted mass azithromycin treatment was not enough to eradicate community-wide trachoma infection. Another study used a proteomic approach to further understand chronic Stevens-Johnson syndrome. A third study needed to obtain information on antimicrobial resistance related to their region since this had not yet been collected, thus preventing health professionals from developing effective treatments for eye infections caused by bacteria. The last study went the technological route and used a 3D printer to comprehend age related macular degeneration.

Annual mass antibiotic distribution versus targeted antibiotic treatment

Trachoma is a bacterial disease caused by bacterium Chlamydia trachomatis that affects the eyes. It is the world’s leading cause of preventable infectious blindness. The typical treatment is the annual distribution of the antibiotic Azithromycin to the whole community. Generally, this has been shown to significantly reduce the spread of trachoma and is a recommended treatment for communities with a prevalence of infection above 5% by the World Health Organization (WHO).

Hamidah Mahmud, BA and researchers from the University of California San Francisco School of Medicine, the University of California San Francisco Department of Ophthalmology, and the Carter Center carried out a cluster-randomized control trial to examine if targeted treatment of those more likely to be infected by trachoma could create a more considerable difference in the frequency of trachoma, in comparison to community-wide distribution. The individuals that are most likely to be infected are children under the age of ten.

They monitored 4,100 children (0-9 years old) annually for both clinical trachoma and ocular chlamydia for three years. The children were from 48 communities in a trachoma hyperendemic area in Amhara, Ethiopia that had received annual mass distribution of azithromycin. They had also been randomized into four groups: age-targeted (6 months – 5 years), household-targeted, annual mass azithromycin, and stop treatment.

Mahmud and team found that there was no difference between the age-targeted and household-targeted treatment methods. “Targeting azithromycin treatment for trachoma to children who carry a higher burden of disease was not enough to eliminate community-wide infection in our hyper-endemic study population.” said Mahmud. This was also the same for the WHO recommended annual mass antibiotic distribution. “However, targeting treatment may be beneficial in less trachoma endemic regions where antibiotic resistance is a cause for concern.”

• Abstract title: Comparing targeted azithromycin treatment strategies in a trachoma hyperendemic area
• Presentation start/end time: Wednesday, May 4, 10am – 12pm MT
• Location: Virtual (https://arvo2022.arvo.org/)
• Abstract Number: 3565 – A0452

 

Tear proteins and their association with chronic eye diseases

In patients suffering from chronic Stevens-Johnson syndrome (SJS), the aftereffects can advance to several eye complications and lead to visual impairment. Unfortunately, it is not well understood the precise process of the interactivity of protein molecules in chronic eye surface inflammation. For this reason, researchers from the L V Prasad Eye Institute in India directed their study towards investigating the molecular signaling pathways to better understand the illness process and “mechanism of ocular damage using a proteomic approach.” This would entail an extensive study of the protein molecules, their structures, and functions.

Madhuri Amulya Koduri, MSc, lead researcher, and team investigated tear samples from chronic SJS patients with “age-gender matched controls”. They were examined by “liquid chromatography-mass spectroscopy for protein profiling and label-free quantification of tear proteins.”

They were able to identify ~1760 total tear proteins and found 249 of them were “differentially regulated proteins”. 63 proteins were determined of which 33 proteins were greatly upregulated and the other 30 proteins were drastically downregulated. For the differentially regulated proteins, it was discovered that the IL-8 signaling pathway and the inflammatory response was a crucial player in chronic SJS tears “and could be correlated with disease conditions.” Koduri said “The findings of this study will lead to better understanding of biology underlying in the ocular surface disease in chronic SJS as well as helps in choosing potential therapeutic targets for development of an effective treatment strategy.”

• Abstract title: Molecular mechanisms in ocular surface disease of chronic Stevens-Johnson syndrome patients using tear proteomics
• Presentation start/end time: Sunday, May 1, 5:15 – 7:15pm MT
• Location: Virtual (https://arvo2022.arvo.org/)
• Abstract Number: 957 – A0426

 

Studying antimicrobial resistance amongst Ghanaian ocular patients

In many cases, eye infections that are caused by bacteria are medicated with antibiotics. Recently, these organisms have built resistance against the standard antibiotics causing major global health problems. As such, healthcare professionals are recommended to take eye swabs to identify the causative agents before dispensing the antibiotics. For resource restricted countries, like Ghana, most professionals go to “broad-spectrum antibiotics in their patients’ treatment modalities.” In addition, the bacteria causing these infections differ based on multiple factors such as the region. Thus, regional research is paramount in providing efficient medical management and equalizing the growth in antimicrobial resistance (AMR).

Researchers from the Kwame Nkrumah University of Science and Technology, Kumasi South Hospital, University of Ghana, and the Anglican Eye Hospital of Jachie in Ghana studied the bacterial causes of “external ocular and periocular infections, and antimicrobial treatment patterns among ophthalmic patients” in their country. They conducted a multicenter cross-sectional study on patients from three hospitals where 114 of them had complete ophthalmic assessments performed on them. Ocular specimens were taken from their eyes and underwent microbial analyses. Lead researcher Isaiah Junior Osei Duah, OD and team separated the bacterial pathogens and had them characterized.

They found that approximately 95% of the samples were conclusive for bacteria culture. 58% were Gram-negative bacteria, 38.8% were Pseudomonas aeruginosa, and 27.6% were Staphylococcus aureus. Osei Duah said “the findings from this study will inform eye care policies on the appropriate use of antibiotic therapy in the routine clinical treatment of eye infections among eyecare providers in Ghana. The baseline country-specific estimates will inform future ocular antimicrobial resistance surveillance studies in this jurisdiction.”

• Abstract title: Bacteria isolates in external ocular and periocular infections and antimicrobial treatment patterns among Ghanaian ophthalmic patients: a multicenter study
• Presentation start/end time: Wednesday, May 4, 10am – 12pm MT
• Location: Virtual (https://arvo2022.arvo.org/)
• Abstract Number: 3557 – A0444

 

3D tissue model sheds light on mechanisms that activate and escalate AMD

Macrophages are specialized cells that help detect and eliminate foreign agents by ingesting and processing them, as well as monitor and guide tissue development and wound healing. They are also important cells involved in chronic inflammation and are crucial in sustaining choroidal function. Lead researcher Russell Quinn, BS, and his team from the National Eye Institute (NEI) and the National Center for Advancing Translational Sciences (NCATS) studied the role of aging/senescent macrophages that contribute to advanced wet age-related macular degeneration (AMD) initiation and progression by using a 3D Outer Blood Retinal Barrier (3D-OBRB) system.

Quinn and his team 3D-printed ocular pericytes, choroidal fibroblasts, endothelial cells, and primary macrophages that were mixed with a collagen-derived gel. They found that macrophages took on “bloated” foam-cell like etiologies, like what is seen in the choroid of advanced AMD patients. The team noticed neo-vascular growths when different combinations of pro and anti-inflammatory macrophages were mixed with in the 3D-OBRB

“We have developed a model system which provides discreet control of cell populations and their densities to simulate healthy and unhealthy physiological tissue environments while maintaining a 3D architecture. Most in vivo systems are not amenable to such a control.” said Quinn, “Utilizing this 3D in vitro system, we were able to establish a link between senescent macrophage populations and initiation of AMD-like phenotypes. After further validation, we hope to use this system to better understand the mechanisms of AMD initiation and progression.” In addition, this model system provides an experimental platform for human ocular tissues and reduces animal usage. Additional aspects of this model system will also be presented by Tea Soon Park, Eric Nguyen, Amir Ali, and Rishabh Hirday at this year’s ARVO conference.

• Abstract title: Senescent Macrophage Lead to Age Related Macular Degeneration-Like Phenotype in an in vitro 3D RPE/Choroid Model
• Presentation start/end time: Sunday, May 1, 12:49 – 1:06pm MT
• Location: 601/603 (Denver Convention Center)
• Also available on the virtual meeting site at https://arvo2022.arvo.org/ beginning May 11
• Abstract Number: 24

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The Association for Research in Vision and Ophthalmology (ARVO) is the largest eye and vision research organization in the world. Members include approximately 10,000 eye and vision researchers from over 75 countries. ARVO advances research worldwide into understanding the visual system and preventing, treating and curing its disorders. Learn more at ARVO.org.

The 2022 ARVO Annual Meeting will take place in Denver, Colo. from May 1 – 4 and virtually May 11 - 12. The Meeting is the premiere gathering of nearly 10,000 eye and vision researchers from around the world. During the Meeting, 4,800 abstracts will be presented on the latest basic and translational research in eye and vision science.

All abstracts accepted for presentation at the Annual Meeting represent previously unpublished data and conclusions. This research may be proprietary or may have been submitted for journal publication. Embargo policy: Journalists must seek approval from the presenter(s) before reporting data from paper or poster presentations. Press releases or stories on information presented at the ARVO Annual Meeting may not be released or published until the following embargo dates:

• May 1: Official launch of presentations of all posters (both presented in-person and virtually)
• Rolling basis: Paper session, Symposia, Minisymposia, Cross-sectional Groups, and invited speaker sessions that have specific presentation times will be embargoed until the end of those individual time slots.

Media contact:
Jenniffer Scherhaufer
1.240.221.2923
media@arvo.org