A Duration-Dependent Interaction Between High-Intensity Light and Unrestricted Vision in the Drive for Myopia Control

Purpose: To evaluate the duration-dependent and synergetic impact of high-intensity light (HL) and unrestricted vision (UnV) on lens-induced myopia (LIM) development in chickens. Methods: Myopia was induced in one eye in chicks (10 groups, n = 126) from day 1 posthatching (D1) until day 8 (D8) using –10 diopter (D) lenses. Fellow eyes remained uncovered as controls. Nine groups were exposed daily to 2, 4, or 6 hours of HL (15,000 lux), UnV (removal of –10 D lens), or both (HL + UnV). One group served as the LIM group without any interventions. Ocular axial length (AL), refractive error, and choroidal thickness were measured on D1, D4, and D8. Outcome measures are expressed as interocular difference (IOD = experimental eye – control eye) ± SEM. Results: By D8, LIM increased AL (0.36 ± 0.04 mm), myopic refraction (−9.02 ± 0.37 D), and choroidal thinning (−90.27 ± 16.44 µm) in the LIM group (all, P < 0.001). Compared to the LIM group, exposure to 2, 4, or 6 hours of HL, UnV, or HL + UnV reduced myopic refraction in a duration-dependent manner, with UnV being more effective than HL (P < 0.05). Only 6 hours of HL + UnV (not 2 or 4 hours) prevented LIM and was more effective than UnV (P = 0.004) or HL (P < 0.001) in reducing myopic refraction and more effective than HL (P < 0.001) in reducing axial elongation. Conclusions: Daily exposure to 2, 4, or 6 hours of HL, UnV, or HL + UnV reduced lens-induced myopic refraction in a duration-dependent manner in chickens. Only 6 hours of HL + UnV completely stopped LIM development. The synergetic effect of HL and UnV is dependent on the duration of the interventions

Efficacy of a novel anti-staphylococcal ectolysin P128 in combination with melittin and its versatility in rabbit eye lesion models and as an antimicrobial wound dressing

With the rise of antimicrobial resistance, there is an urgency for the development of newer antimicrobial agents with novel modes of action. GangaGen Inc. has developed an innovative bacteriophage-derived anti-staphylococcal ectolysin “P128”, which cleaves pentaglycine bridges of bacterial cell membranes. My co-supervisor’s lab has recently developed bee venom-derived antimicrobial melittin peptide derivatives “Mel4” and “Mel5”. Here, we investigated in vitro and in vivo biocompatibility and efficacy of P128 alone and in combination with Mel4/Mel5. We demonstrated that P128 can kill staphylococcal strains with minimum inhibitory concentrations (MIC) 2-8 µg/mL without causing any major toxicity to cultured human cells, even at elevated concentrations (640 µg/mL). Both Mel4 and Mel5 were effective against broad-spectrum pathogenic bacteria, with MIC 8-128 µg/mL. In a rabbit S. aureus keratitis model, P128 displayed therapeutic effects similar to comparator antibiotic Gatifloxacin and did not interfere with wound healing. Moreover, P128-loaded electrospun sodium alginate/polyethylene oxide – polycaprolactone/gelatin core-shell fibers were cytocompatible with cultured mammalian cells and exhibited contact-mediated antimicrobial activity. Furthermore, combinations of P128 with Mel4/Mel5 displayed synergistic effects against a panel of Gram-positive and Gram-negative bacteria. In conclusion, P128 is a versatile antimicrobial that can be combined with Mel4/Mel5 for treating broad-spectrum bacterial infections.Bachelor of Science in Biological Science

Light and myopia: from epidemiological studies to neurobiological mechanisms

Myopia is far beyond its inconvenience and represents a true, highly prevalent, sight-threatening ocular condition, especially in Asia. Without adequate interventions, the current epidemic of myopia is projected to affect 50% of the world population by 2050, becoming the leading cause of irreversible blindness. Although blurred vision, the predominant symptom of myopia, can be improved by contact lenses, glasses or refractive surgery, corrected myopia, particularly high myopia, still carries the risk of secondary blinding complications such as glaucoma, myopic maculopathy and retinal detachment, prompting the need for prevention. Epidemiological studies have reported an association between outdoor time and myopia prevention in children. The protective effect of time spent outdoors could be due to the unique characteristics (intensity, spectral distribution, temporal pattern, etc.) of sunlight that are lacking in artificial lighting. Concomitantly, studies in animal models have highlighted the efficacy of light and its components in delaying or even stopping the development of myopia and endeavoured to elucidate possible mechanisms involved in this process. In this narrative review, we (1) summarize the current knowledge concerning light modulation of ocular growth and refractive error development based on studies in human and animal models, (2) summarize potential neurobiological mechanisms involved in the effects of light on ocular growth and emmetropization and (3) highlight a potential pathway for the translational development of noninvasive light-therapy strategies for myopia prevention in children

A duration-dependent interaction between high-intensity light and optical refocus in the drive for myopia control

PURPOSE To evaluate the duration-dependent and synergetic impact of high-intensity light (HL) and optical refocus (RF) on lens-induced myopia (LIM) development in chickens. METHODS Myopia was induced in one eye in chicks (10 groups, n=126) from day 1 post- hatching (D1) until D8 using -10D lenses. Fellow eyes remained uncovered as controls. Nine groups were exposed daily to continuous 2 hours (h), 4h, or 6h of either HL (15,000 lux); RF (removal of -10D lens); or both (HL+RF). One group served as the LIM group without any interventions. Ocular axial length (AL), refractive error, and choroidal thickness were measured on D1, D4, and D8. Outcome measures are expressed as inter-ocular difference (IOD= experimental - control eye) ±SEM. RESULTS By D8, LIM increased AL (0.36±0.04 mm), myopic refraction (-9.02±0.37D), and choroidal thinning (-90.27±16.44 µm) in the LIM group (all, P CONCLUSION Daily exposure to 2h, 4h, or 6h of HL, RF, or HL+RF reduced lens-induced myopic refraction in a duration-dependent manner in chickens. Only 6h of HL+RF completely stopped LIM development. The synergetic effect of HL and RF is dependent on the duration of the interventions