Purpose: The purpose of this study is to evaluate effects of vitrectomy (PPV) and lens extraction with intraocular lens implantation (PE/IOL) on molecular oxygen (pO2) distribution, aqueous humor antioxidant-oxidant balance, aqueous humor dynamics, and histopathologic changes in the trabecular meshwork (TM) in the older macaque monkey.
Methods: Six rhesus monkeys underwent PPV followed by PE/IOL. pO2, outflow facility, and intraocular pressure (IOP) were measured. Aqueous and vitreous humor specimens were analyzed for antioxidant status and 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative damage. TM specimens were obtained for immunohistochemical and quantitative PCR analysis.
Results: pO2 at baseline revealed steep gradients in the anterior chamber and low levels in the posterior chamber (PC) and around the lens. Following PPV and PE/IOL, pO2 significantly increased in the PC, around the IOL, and angle. IOP increased following both surgical interventions, with no change in outflow facility. Histopathologic analysis did not show changes in TM cell quantification, but there was an increase in 8-OHdG. Quantitative PCR did not reveal significant differences in glaucoma-related gene expression. Aqueous and vitreous humor analysis revealed decreased ascorbate and total reactive antioxidant potential and increased 8-OHdG in the aqueous humor only in the surgical eyes.
Conclusions: Oxygen distribution in the older rhesus monkey is similar to humans at baseline and following surgical interventions. Our findings of histopathologic changes of TM oxidative damage and alterations in the oxidant-antioxidant balance suggest a potential correlation of increased oxygen exposure with oxidative stress/damage and the development of open angle glaucoma.
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http://dx.doi.org/10.1167/iovs.17-21890 | DOI Listing |
J Vet Med Sci
January 2025
Department of Small Animal Internal Medicine II, School of Veterinary Medicine, Kitasato University.
This study investigated the anti-inflammatory effects of water-dispersible hesperetin (WD-Hpt) in an endotoxin-induced uveitis (EIU) rat model. The rats were orally administered 10, 25, or 50 mg/kg WD-Hpt immediately after lipopolysaccharide (LPS) injection at the concentration of 200 μg. Clinical scores, cellular inflammation, the aqueous humor (ApH) protein concentration, as well as the levels of tumor necrosis factor (TNF)-α, cyclooxygenase (COX)-2 and inducible NO synthase (iNOS) in AqH, and histopathological grades were assessed.
View Article and Find Full Text PDFPrcis: Trabecular cutting minimally invasive glaucoma surgery like bent ab interno needle goniectomy (BANG) when performed in baseline aqueous angiography identified low aqueous humor outflow regions, results in greater success of intraocular pressure reduction.
Purpose: To study the efficacy of Bent Ab Interno Needle Goniectomy (BANG) in high versus low aqueous humor outflow (AHO) regions as determined by Aqueous Angiography(AA) in patients with primary open angle glaucoma (POAG).
Methods: A prospective, single-centre, pilot, randomized control trial recruited 30 eyes of 30 patients of POAG and visually significant cataract (45-80 y) and were randomised into two groups ("A": BANG performed in the high-flow regions and "B": BANG performed in the low-flow regions) of 15 each.
Invest Ophthalmol Vis Sci
January 2025
State Key Laboratory of Ophthalmology, Optometry, and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China.
Purpose: Changes associated with Alzheimer's disease (AD) may have measurable effects on the retina, which may facilitate early detection due to the eye's accessibility. Retinal pathology and the regulation of serine racemase (SR) were investigated in the retinas of APP(SW)/PS1(∆E9) mice.
Methods: SR in the retinas and the content of D-serine in the aqueous humor were analyzed.
Croat Med J
December 2024
Marijan Klarica, Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Šalata 3b, 10000 Zagreb, Croatia,
It is generally accepted that intraocular pressure (IOP) depends on the rate of aqueous humor production, system outflow resistance, and episcleral venous pressure. Therefore, control IOP values are expected to be within the strict and predictable limits in specific animal species, and there should be no vast differences between species. However, in the literature the control IOP values significantly vary (from potentially "hypotensive" to "hypertensive") within the same species, and especially between species depending on the measurement technique, head position in relation to the rest of the body, circadian rhythm, age, and topical and systemic drugs (anesthetics) applied.
View Article and Find Full Text PDFKlin Monbl Augenheilkd
January 2025
Minimally invasive glaucoma surgeries (MIGS) offer an alternative approach, aiming to be both safe and effective. Defined by their ab interno technique, which avoids creating a bleb, MIGS procedures seek to reduce intraocular pressure (IOP) by enhancing the outflow pathways of aqueous humor. Techniques include stenting, incisions, and excisions of the trabecular meshwork, canaloplasty of Schlemm's canal, and drainage implants that enhance uveoscleral outflow to the subchoroidal space.
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