Modelling form deprivation myopia in experiment

Mikheytseva, Irina N.; Abdulhadi, Mohammad; Putienko, A.; Kovalchuk, Andrii; Kolomiichuk, S.; Siroshtanenko, T.

doi:10.31288/oftalmolzh/2018/2/5055

Cited by 3 publications

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“…Deprivation myopia was produced in two-week animals by surgically fusing the eyelids of both eyes [10]. Thereafter, these animals were maintained under conditions of reduced illumination for two weeks to induce a more intense myopization of the globe [11]. Eyelid sutures were removed on completion of these two weeks.…”

Section: Methodsmentioning

confidence: 99%

Ultrastructural changes in the chorioretinal complex of the rat after inducing form-deprivation axial myopia only, diabetic retinopathy only and diabetic retinopathy in the presence of myopia

Mykheitseva¹,

Molchaniuk²,

Muhammad³

et al. 2021

Oftalmol Zh

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To determine the features of the microstructure of choreoretinal complex in rats with diabetes induced by streptozotocin in the presence of axial myopia. Material and Methods: Fifty-five Wistar rats (110 eyes; age, 2 weeks to 14 weeks) were used in experiments. Four groups were formed: group 1 (axial myopia only); group 2 (diabetes only); group 3 (both myopia and diabetes); and group 4 (controls; intact animals). High form-deprivation myopia was produced in two-week animals by surgically fusing the eyelids of both eyes and these animals were maintained under conditions of reduced illumination for two weeks to induce a more intense myopization of the globe. Eyelid sutures were removed on completion of these two weeks. Two weeks thereafter, type 2 diabetes mellitus was induced in rats with induced axial myopia and intact rats. A 50 mg/kg intraperitoneal streptozotocin injection for 5 days was used for this purpose. Elongated axial length and increased anterior chamber depth as measured by in vivo ultrasound were an objective criterion of the development of myopia in experimental animals. A glucose level of ≥ 4.5 mmol/L was a criterion of the development of diabetes. Two months after inducing diabetes, 14-week rats were sacrificed, and their eye tissue samples were processed by a routine method and assessed by electron microscopy. Ultrastructure of the choroid, RPE, and retinal photoreceptor cells were examined. Ultra-thin sections were cut, stained with lead citrate according to the procedure described by Reynolds, and observed with a PEM-100-01 Transmission Electron Microscope. Results: Our ultrastructural study found that myopization of the rat globe with elongation of the axial length somewhat reduced the severity of some ultrastructural changes in the choreoretinal complex in induced type 2 diabetes due to reduced choroidal swelling and dominance of compensatory processes with increased energy producing, protein synthesis and other functions in the endothelial vessels and choriocapillaries as well as RPE cells. Out findings seem to corroborate the concept that myopized eyes have capacity to somewhat buffer the development of severe diabetic retinopathy, likely due to some compensatory-andrestorative processes.

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Section: Methodsmentioning

confidence: 99%

Ultrastructural changes in the chorioretinal complex of the rat after inducing form-deprivation axial myopia only, diabetic retinopathy only and diabetic retinopathy in the presence of myopia

Mykheitseva¹,

Molchaniuk²,

Muhammad³

et al. 2021

Oftalmol Zh

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“…До 1-ї контрольної групи ввійшли інтактні тварини (n = 10), до 2-ї -щури з міопією (n = 15), до 3-ї -з діабетом (n = 15); до 4-ї -з міопією і діабетом (n = 15). Експеримент починали на 2-тижневих щурах, яким моделювали осьову міопію підвищеного ступеня блефарорафією обох очей і знаходженням в умовах зниженого освітлення протягом ще 2 тиж [7]. Стрептозотоциніндукований діабет моделювали кратним внутрішньоочеревинним введенням субдіабетичних доз стрептозотоцину (15,0 мг/кг маси) протягом 5 днів.…”

Section: методикаunclassified

Features of Ultrastructural Changes in the Neurosensory Elements of the Retina of Rats in the Modeling of Diabetic Retinopathy on the Background of Axial Myopia

Mikheytseva,

Molchanuk,

Amayed

et al. 2024

Fiziol Zh

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The formation and development of diabetic retinopathy in conditions of myopization of the eyeball is accompanied by the features of the clinical picture of retinopathy. With myopia, the incidence of especially proliferative retinopathy, as well as the rate of progression of these diabetic changes in the retina, can be reduced. The aim of our work was a comparative study of the ultrastructure of the neurosensory elements of the retina in rats in the simulation of streptozotocin-induced diabetes and deprivation axial myopia. Experiments were performed on rats aged from 2 to 10 weeks, which were divided into 4 groups. The 1st control group included intact animals, the 2nd - with myopia, the 3rd - with diabetes; the 4th - with myopia and diabetes. Two-week-old rats were modeled with a high degree of axial myopia by blepharorrhaphy of both eyes and exposure to low light for another 2 weeks. In rats with axial myopia and intact rats, streptozotocin-induced diabetes was modeled by repeated intraperitoneal administration of subdiabetic doses of streptozotocin (15.0 mg/kg body weight) for 5 days. After 2 months, all animals were removed from the experiment under anesthesia and their eyes were enucleated. The tissue samples were photographed in a PEM-100-01 electron microscope and the ultrastructure of the neurosensory elements of the retina was studied. The obtained results of the study indicate that ultrastructural retinal neurosensory elements differed in different groups. When modeling diabetes against the background of axial myopia, some areas with signs of hydropic dystrophy with large fields of organelle destruction were observed in the cells of the inner layers of the retina, mainly in the inner nuclear layer, which is inherent in diabetes, but there were also areas whose ultrastructure was close to normal. This indicates that the process of myopization of the eyeball of rats with the lengthening of the anterior-posterior axis can mitigate the severity of ultrastructural changes of the retina in the simulation of diabetic retinopathy.

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“…Було сформовано чотири групи: 1 -з осьовою міопією (n=15); 2 -з діабетом (n=15); 3 -з міопією та діабетом (n=15); 4 -контрольна (інтактні тварини, n=10). Осьову міопію підвищеного ступеня у двотижневих тварин викликали шляхом блефарорафії обох очей та знаходженням в умовах зниженого освітлення протягом ще 2-х тижнів [19]. Потім у 15 щурів групи з осьовою міопією та у 15 інтактних щурів мо-делювали стрептозотоцин-індукований діабет кратним внутрішньоочеревинним введенням субдіабетичних доз стрептозотоцину (15,0 мг/кг маси) протягом 5 днів.…”

Section: матеріал та методиunclassified

Retinal energy state in rats with experimental diabetes and axial myopia

Михейцева,

Амаієд,

Коломійчук

2023

Oftalmol Zh

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Background: Elucidating the pathogenesis of diabetic retinopathy (DR) for further development of methods of treatment and prevention of the disease is an important medical and social task for ophthalmologists. The development of DR in the presence of myopia has some special features. In the presence of myopia, the diabetic complications in the retina are less severe than in emmetropia. The mechanisms of this paradoxical impact of eye myopization on the severity of these complications are, however, still unknown. Purpose: To examine the state of retinal energy metabolism based on evaluation of biochemical markers of mitochondrial function (lactate, pyruvate, adenosine triphosphate (ATP) and adenosine diphosphate (ADP) levels and succinate dehydrogenase activity) in rats with streptozotocin (STZ)-induced diabetes that developed in the presence of axial myopia, compared to rats with diabetes alone and those with myopia alone. Material and Methods: High axial myopia was produced in two-week animals by surgically fusing the eyelids of both eyes and maintaining these animals under conditions of reduced illumination for two weeks. A 15 mg/kg intraperitoneal streptozotocin injection for 5 days was used for inducing diabetes mellitus in rats with induced axial myopia and intact rats. Animals in the control group were maintained under conditions of natural illumination. In two months, all rats were euthanized under anesthesia, and their eyes were enucleated. ATP, ADP, lactate, and pyruvate levels were measured in blood and retinal specimens and ATP/ADP ratio and lactate/pyruvate ratio were determined. Succinate dehydrogenase activity was determined in isolated retinal mitochondria. For statistical analysis of biochemical results, Student’s t-test was conducted (Statistica software). Results: Rats with diabetes alone exhibited lower retinal and plasma energy metabolism characteristics (ATP, ADP, and succinate dehydrogenase activity), and developed retinal hypoxia, with retinal lactate and pyruvate levels being 1.838-fold and 1.455-fold higher, respectively, and their ratio, 26.5% higher, compared to controls. In animals with STZ-induced diabetes in the presence of axial hypoxia, retinal lactate and pyruvate levels were 20.2% and 15.5% lower, respectively, and their ratio was lower (36.5 versus 38.7), compared to rats with diabetes alone, indicating lower hypoxia in the setting of eye myopization. In addition, in rats with diabetes in the presence of axial hypoxia, plasma and retinal ATP levels were 21.8% and 21.2% higher, respectively, and retinal succinate dehydrogenase activity, 20.8% higher, compared to rats with diabetes alone. Conclusion: In experimental diabetes, an increase in the axial length of the eye (i.e., eye myopization) is accompanied by activation of energy processes and the development of hypoxia adaptation in retinal cells.

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Modelling form deprivation myopia in experiment

Cited by 3 publications

References 0 publications

Ultrastructural changes in the chorioretinal complex of the rat after inducing form-deprivation axial myopia only, diabetic retinopathy only and diabetic retinopathy in the presence of myopia

Ultrastructural changes in the chorioretinal complex of the rat after inducing form-deprivation axial myopia only, diabetic retinopathy only and diabetic retinopathy in the presence of myopia

Features of Ultrastructural Changes in the Neurosensory Elements of the Retina of Rats in the Modeling of Diabetic Retinopathy on the Background of Axial Myopia

Retinal energy state in rats with experimental diabetes and axial myopia

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