• Journal of Veterinary Clinics
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• v.19 no.4
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• pp.461-463
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• 2002

Pharmacological ablation of the ciliary body by intravitreal injection of a cytotoxic dose of gentamicin was utilized for the treatment of absolute glaucoma in 13 dogs. Complications of this procedure were hyphema(2), corneal opacity(2), iris bombe(1), cataract(1) and chronic inflammation(1). Injection time was one time in 10 dogs, two times in 2 dogs and 3 times in a dog. Intravitreal injection of gentamicin was thought as a economic salvage procedure and has resulted in successful lowering of intraocular pressure.

• Journal of Veterinary Clinics
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• v.19 no.3
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• pp.333-336
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• 2002

This experiment was carried out to investigate the optimal dose of intravitreal gentamicin that decreases intraocular pressure effectively and minimizes complications in dog. After inhalation anesthesia, gentamicin was injected intravitreally into the left eyes at doses of 10, 15 and 20 mg with 1 mg dexamethasone, respectively. Sterilized isotonic saline and dexamethasone mixture into the right eyes for control. Six dogs were used in each group. Intraocular pressures were measured using applanation tonometer(Mentore, Tono-Pen) until 5 months after injection of gentamicin. Ocular examinations were performed using direct ophthalmoscopy. The ocular volumes of both eyes were measured. Intraocular pressures of eyes injected with 10. 15 and 20 mg of gentamicin were decreased significantly compared with control eyes. Severe corneal opacity and neovascularization occurred in 20 mg treated group. Intraocular hemorrhage was observed in 3 dogs of 20 mg treated group. Ocular volume was significantly decreased(p <0.05) in 20 mg treated group, compared with 10 and 15 mg treated group. It is considered that intravitreal gentamicin injection at dose of 10 mg or 15 mg decrease intraocular pressure effectively and minimize complications such as corneal opacity, hyphema and phthisis bulbus.

• Journal of Veterinary Clinics
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• v.34 no.5
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• pp.341-346
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• 2017

This study was performed to evaluate the effects of an intravitreal injection of cidofovir in beagle dogs. Nine beagle dogs (18 eyes) were used and randomly assigned to the following three groups of various dosages: 100, 500 and $1000{\mu}g$. Aqueous paracentesis was followed by an intravitreal injection of cidofovir. Intraocular pressure (IOP) was measured twice a week and electroretinography (ERG) and ophthalmoscopic examination were performed every week during the study. At the end of the study, all eyes were enucleated for histopathologic evaluation after euthanasia. The IOPs in the 500 and $1000{\mu}g$ groups were statistically lower than baseline with no significant IOP changes in the $100{\mu}g$ group. Reduced amplitudes of ERG recordings were identified in the eyes injected with higher dose groups than the $100{\mu}g$ group. Histopathologic examination revealed that there were dose-related toxicities to the ciliary body and the retina. These results suggest that intravitreal cidofovir had dose-dependent IOP lowering effects associated with ciliary body destruction, but had the potential to cause retinal toxicity in beagle dogs.

• Journal of Korean Clinical Nursing Research
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• v.27 no.1
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• pp.54-65
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• 2021

Purpose: The purpose of this study was to identify influencing factors on vision-related quality of life in patients with retinal diseases receiving intravitreal injections by examining relationships among anxiety, depression, coping, eye health behaviors and vision-related quality of life. Methods: One hundred and five outpatients who were diagnosed with macular degeneration and diabetic retinopathy were recruited from one university hospital during August 16, 2019 to March 25, 2020. Data were analyzed using descriptive statistics (frequency and percentage, mean, standard deviation), and t-tests, ANOVA, Scheffé test, Pearson's correlations, and stepwise multiple regressions using the IBM SPSS Statistics 25.0. Results: The vision-related quality of life according to general characteristics of retinal disease patients with intravitreal injection showed significant differences in age (F=3.01, p=.034), subjective economic status (F=5.83, p=.004), types of retinal disease (t=2.62, p=.010), and disease in both eyes (t=-3.04, p=.003). The vision-related quality of life showed a significant positive correlation with age (r=.24, p=.012), and negative correlations with anxiety (r=-.66, p<.001), depression (r=-.48, p<.001), and emotion-focused coping (r=-.20, p=.036). The hierarchical regression analysis indicated that factors affecting vision-related quality of life in patients with retinal diseases were anxiety and subjective economic status, accounting for 47.0% of the variances of the vision-related quality of life. Conclusion: Based on our results, health professionals need to pay attention to patients with low socioeconomic status due to frequent treatments. Also, a program needs to be developed to decrease anxiety for outpatients receiving intravitreal injections to improve their vision-related quality of life.

• Design & Manufacturing
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• v.17 no.1
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• pp.40-47
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• 2023

Macular degeneration and glaucoma are representative age-related retinal diseases that rank second and third in the prevalence of retinal diseases, and are a kind of degenerative neurological disease. Irreversible visual acuity and visual field damage may occur, and the number of patients is rapidly increasing as the population ages. Since this retinal disease is a chronic disease, continuous drug treatment is required. There are various drug delivery methods for treatment, but direct injection of the drug into the intravitreal is the most effective for continuous delivery of the drug over a long period of time. In order to solidify Dexamethasone, a retinal disease treatment, and insert it into the primary intravitreal, it is important to develop a technology to miniaturize the treatment and an applicator to deliver the treatment. In this study, a mold technology was developed to integrate the cannula and hub, which are one part of applicator. In addition, surface treatment was performed on the outside of the cannula to improve the bonding strength between the cannula and the hub, and the bonding strength according to each condition was analyzed through a tensile test.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.247-254
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• 1990

Chicken monocular head and eye optokinetic nystagmus (OKN) were observed by coil recordings after intravitreal administration of GABA antagonists (picrotoxin and bicuculline) into the opened and closed eye. Before injection of drugs the chicken displayed an OKN for T-N stimulation being more efficient in evoking this visuomotor reflex than for N-T stimulation. The injection of GABA antagonist into the opened eye provoked a decrease or disappearance of the head and eye OKN. On the other hand, the injection of GABA antagonist into the closed eye, the head and eye OKN augmented. Thus, GABA antagonist abolished the directional asymmetry of the head and eye OKN, indicating the involvement of GABAergic mechanisms in the inhibition of the N-T component of the monocular OKN.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.3
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• pp.219-224
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• 2012

Understanding how the b-wave of the electroretinogram (ERG) is generated by full-field light stimulation is still a challenge in visual neuroscience. To understand more about the origin of the b-wave, we studied the contributions of gap junctions to the ERG b-wave. Many types of retinal neurons are connected to similar and different neighboring neurons through gap junctions. The photopic (cone-dominated) ERG, stimulated by a small light beam, was recorded from goldfish (Carassius auratus) using a corneal electrode. Data were obtained before and after intravitreal injection of agents into the eye under a photopic illumination level. Several agents were used to affect gap junctions, such as dopamine D1 and D2 receptor agonists and antagonists, a nitric oxide (NO) donor, a nitric oxide synthase (NOS) inhibitor, the gap junction blocker meclofenamic acid (MFA), and mixtures of these agents. The ERG b-waves, which were enhanced by MFA, sodium nitroprusside (SNP), SKF 38393, and sulpiride, remained following application of a further injection of a mixture with MFA. The ERG b-waves decreased following $N^G$-nitro-L-arginine methyl ester (L-NAME), SCH 23390, and quinpirole administration but were enhanced by further injection of a mixture with MFA. These results indicate that gap junction activity influences b-waves of the ERG related to NO and dopamine actions.

• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1142-1151
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• 2018

Purpose: We assessed the visual and anatomical outcomes, and the safety profile of long-term intravitreal anti-vascular endothelial growth factor (VEGF) injections (aflibercept, ranibizumab, and bevacizumab) given to treat neovascular age-related macular degeneration (NAMD). Methods: We analyzed medical records collected over 7 years of treatment-naive NAMD patients who received outpatient clinic-based intravitreal anti-VEGF injections. All were treated employing either "treat-and-extend" or "as needed" protocols at the discretion of the retinal specialist. The number of injections, adverse events associated with injection, and measures of visual acuity (VA), central foveal thickness (CFT), and intraocular pressure (IOP) were recorded. Results: Overall, we assessed 196 eyes of 196 patients (average age $68.6{\pm}9.6years$; 77 females). Patients received an average of $17.3{\pm}13.5$ injections over $78.0{\pm}16.5months$ of clinical follow-up. The initial mean VA (logMAR) was $0.75{\pm}0.58$ and the CFT was $349.7{\pm}152.6{\mu}m$. Both parameters exhibited maximal improvements at the 6-month visit (p < 0.05). However, the clinical outcomes worsened over the 7-year clinical course; the best-corrected visual acuity (BCVA) was $0.91{\pm}0.78$ and the CFT was $284.5{\pm}105.8{\mu}m$ at 7 years. The BCVA at 7 years was significantly correlated with the initial BCVA. IOP-related events increased 11-fold and anterior chamber reactions increased 3-fold over the years, but no significant complications such as endophthalmitis were recorded. Conclusions: The use of intravitreal anti-VEGF agents was associated with initial visual improvements over 6 months but did not prevent the worsening of NAMD over 5 years. The BCVA at the initial visit was a strong predictor of the final BCVA. A more intensive injection schedule might improve long-term outcomes.

• BMB Reports
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• v.51 no.7
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• pp.315-316
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• 2018

Genome engineering with clustered regularly interspaced short palindromic repeats (CRISPR) system can be used as a tool to correct pathological mutations or modulate gene expression levels associated with pathogenesis of human diseases. Owing to well-established local administration methods including intravitreal and subretinal injection, it is relatively easy to administer therapeutic genome engineering machinery to ocular tissues for treating retinal diseases. In this context, we have investigated the potential of in vivo genome engineering as a therapeutic approach in the form of ribonucleoprotein or CRISPR packaged in viral vectors. Major issues in therapeutic application of genome engineering include specificity and efficacy according to types of CRISPR system. In addition to previous platforms based on ribonucleoprotein and CRISPR-associated protein 9 derived from Campylobacter jejuni, we evaluated the therapeutic effects of a CRISPR RNA-guided endonuclease derived from Lachnospiraceae bacterium ND2006 (LbCpf1) in regulating pathological angiogenesis in an animal model of wet-type age-related macular degeneration. LbCpf1 targeting Vegfa or Hif1a effectively disrupted the expression of genes in ocular tissues, resulting in suppression of choroidal neovascularization. It was also notable that there were no significant off-target effects in vivo.

• Pediatric Infection and Vaccine
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• v.27 no.3
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• pp.198-204
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• 2020

Cytomegalovirus (CMV) disease is rare in children who receive anticancer chemotherapy and have no history of stem cell transplantation (SCT). We report a case of CMV retinitis that developed during maintenance chemotherapy for acute leukemia. A 7-year-old boy developed decreased visual acuity and persistent pancytopenia during maintenance chemotherapy. Laboratory investigations initially showed significant CMV antigenemia (51 positive cells/200,000 leukocytes); however, antiviral therapy was not deemed necessary in this patient who had no history of SCT. CMV antigenemia worsened to 170 positive cells/200,000 leukocytes over 3 weeks. Ophthalmological examination revealed multiple bilateral retinal infiltrates and granular lesions. He was diagnosed with CMV retinitis and was treated with a 4-week course of intravenous ganciclovir and intravitreal injection of ganciclovir 6 times, followed by a 1-month course of orally administered valganciclovir. A CMV antigenemia assay showed negative results, and follow-up fundoscopy revealed lesser retinal infiltration after the sixth intravitreal ganciclovir injection. Future studies should focus on the development of standardized screening methods and preemptive therapeutic strategies for CMV disease in high-risk children.