Collagen-based scaffolds with infused anti-VEGF release system as potential cornea substitute for high-risk keratoplasty: A preliminary in vitro evaluation

Currently the only widely accepted corneal blindness treatment is human donor cornea transplantation. However, increasing shortage of donor corneas as well as high risk of rejection in some corneal diseases remain two major problems, which limit the success of corneal transplantation. Corneal neovascularization is considered as one of the main risk factors of graft failure. Different cell-free biosynthetic scaffolds fabricated from collagens or collagen-like peptides are being tested as donor cornea substitutes (DCS). Here, we report for the first-time composite biosynthetic DCS with integrated sustained release system of anti-VEGF drug, bevacizumab and their preliminary in vitro validation. We have tethered gold nanoparticles with bevacizumab and integrated into a collagen-based cell-free hydrogel scaffold. Developed grafts preserved good optical properties and were confirmed not toxic to human corneal epithelial cells. Bevacizumab has been shown to constantly releasing from the DCS up to 3 weeks and preserved its anti-angiogenic properties. These results provide background for further use of infused composite biosynthetic DCS with integrated nanosystem of bevacizumab sustained release in corneal disease accompanied by neovascularisation where conventional corneal transplantation might fail

Heat exchange in the human eye: a review

Thermal homeostasis is required in order to ensure that the normal function of the human body is maintained under various environmental conditions. Various pathological processes impacting metabolism in tissues and organs (e.g., the human eye) are accompanied by changes in relative internal heat balance. Although numerous relevant studies have been conducted, heat exchange processes in the human eye have not been yet sufficiently investigated. Further research on the features of heat exchange in the eye is required not only to improve our knowledge in the field of physiology of the eye, but also to use the data obtained for developing novel advanced techniques for eye disease diagnosis and treatment

Ocular hypotensive efficacy of a new liposomal latanoprost formulation administered by different routes for experimental ocular hypertension

Background: Prostaglandin analogs (e.g., latanoprost) are the first-line therapy for glaucoma. These medications, however, have a short antihypertensive effect due to low penetration of topical drug across the corneal epithelium, which causes the need for their daily application for a long time. Therefore, it is clinically and socially important to develop latanoprost medications with improved efficacy against ocular hypertension (OHT) and with improved patient compliance through the prolonged effect of latanoprost. Purpose: To assess (a) changes in intraocular pressure (IOP) with time and (b) duration of hypotensive effect of a proprietary liposomal latanoprost formulation administered topically or by subconjunctival injection for experimental OHT. Material and Methods: Twenty-one adult Chinchilla rabbits (age, 1 year; weight, 2.5 to 3.0 kg) were divided into three groups: group 1, animals with induced OHT, which was treated with topical liposomal latanoprost (n = 7); group 2, animals with induced OHT, which was treated with a single subconjunctival injection of liposomal latanoprost (n = 7); and group 3, untreated animals with induced OHT, (n = 7). OHT was induced by two 0.1-mL anterior chamber injections of 0.3% carbomer at 10 day intervals. A 0.1-ml subconjunctival injection of liposomal latanoprost formulation was applied immediately after formation of the model of OHT. Topical liposomal latanoprost (one drop per eye) was bilaterally applied at a dose of 1 drop per eye once daily in the evening. Follow-up duration was 10 weeks. IOP was measured in each group before and after OHT modeling. In addition, it was measured after subconjunctival injection of liposomal latanoprost or first application of topical liposomal latanoprost. Thereafter, IOP measurements were performed once a week. Statistica 5.5 (StatSoft, Tulsa, OK, USA) software was applied for statistical analysis. Non-parametric statistical tests for dependent and independent samples were used. Results: We assessed the pharmacological efficacy and duration of hypotensive effect of a proprietary liposomal latanoprost formulation administered topically or by subconjunctival injection for experimental OHT in rabbits. After OHT modeling was performed, there was a persistent increase in IOP, with the IOP values being 51-65% higher than at baseline (р < 0.001). The IOP in animals with OHT treated daily with topical liposomal latanoprost was 30.5% lower than in untreated animals with OHT (р < 0.001). A single subconjunctival injection of the examined liposomal latanoprost formulation resulted in a 36.7% reduction in IOP compared to baseline (р ˂ 0.001), with the effect being as long as 10 weeks. Conclusion: The current study demonstrated a statistically significant hypotensive effect of topical or subconjunctival injection treatment with the examined liposomal latanoprost formulation, with the effect of a single subconjunctival injection of the formulation being as long as 10 weeks

Determination of electric current threshold parameters for high-frequency electric welding of the retina in experiment and based on two-dimensional numerical simulation depending on the intraocular contents (vitreous, perftordekalin, air)

Мета роботи – визначити порогові параметри електричного струму при високочастотному електрозварюванні сітківки в експерименті в залежності від внутрішньоочного вмісту та обгрунтувати їх за допомогою двомірного чисельного моделювання.Introduction. High-frequency electric welding (HFEW) is used in vitreoretinal surgery for retinopexy and haemostasis. Parameters of electric current may depend on the tamponade of the vitreous cavity. Purpose. To determine threshold parameters of the electric current of HFEW of the retina in depending on the intraocular content (vitreous, perfluorodecalin) and give reasons for preference on the basis of two-dimensional numerical simulation.Цель работы – определить пороговые параметры электрического тока при высокочастотной электросварке сетчатки в эксперименте в зависимости от внутриглазного содержимого и обосновать их на основании двухмерного численного моделирования

Effect of recombinant erythropoietin on structural changes of the retina, hemoglobin concentration and erythrocytes quantity in peripheral blood in streptozotocin-induced diabetic rats

Introduction. Recently the role of erythropoietin (Epo) in the development of diabetic retinopathy has been studied. Purpose. To determine the effect of recombinant erythropoietin (rEpo) on structural peculiarities of the retina, hemoglobin concentration and erythrocyte quantity in peripheral blood in streptozotocin-induced diabetes animals. Methods. 30 Vistar rats were included in the experiment. Diabetes was simulated using a single intraperitoneal injection of streptozotocin in a dose of 65 mg per 1 kg body weight. All rats were divided into three groups, each of 10 rats (20 eyes). Group 1 consisted of intact rats; group 2 — of streptozotocin-induced diabetes rats not receiving rEpo; group 3 — of streptozotocin-induced diabetes rats receiving rEpo. REpo administration started on the 10th day in a dose of 60 units per 1 kg of body weight three times a week during two weeks. Results. Epo was detected in peripheral blood and vitreous of intact rats. Erythrocyte quantity and hemoglobin concentration in blood didn’t change in rats of Group 2. REpo administration in Group 3 led to significant increase of Epo concentration in peripheral blood and vitreous, increase of erythrocyte quantity and hemoglobin concentration. Development of retinal edema, vacuolar degeneration of retinal ganglion cells, signs of destructive changes in the retinal capillaries walls were noted in animals of Group 2, and rEpo administration significantly reduced the risk of development of those complications in Group 3.Актуальність. Останім часом ведуться дослідження про роль еритропоетину в розвитку та прогресуваггі діабетичної ретинопатії. Метою цього дослідження є визначення впливу рекомбінантного ЕПО у тварин з стрептозотоциновим діабетом на структурні особливості сітківки, а також концентрацію гемоглобіну та кількість ерітроцитіву периферичній крові. Матеріал і методи. Експеримент проведенийна30 щурах породи Вістар. Цукровий діабет моделювали за допомогою одноразового внутрішньочеревного введення стрептозотоцину в дозі 65 мг на 1 кг ваги. Всі щури розподілялися на три групи, по десять щурів (20 очей) у кожній групі. І группа – інтактні тварини, ІІ группа – тварини з модельованим діабетом, ІІІ – тварини з модельованим діабетом, что отримували рЕПО. Результати. У інтактних тварин в периферичній крові та скловидному тілі визначаеться еритропоетин. Введення тваринам ІІІ групі рЕПО призводить до достовірного підвищення концентрації ЕПО в периферичній крові та скловидному тілі, збільшення кількості еритроцитів та концентрації гемоглобіну. У тварин ІІ групи відзначається розвиток набряку сітківки, вакуольна дегенерація гангліозних клітин сітківки, ознаки деструктивних змін стінок частини капілярів сітківки, а введення тваринам ІІІ групи рЕПО істотно зніжує ймовірність ціх змін

Diagnostic possibilities of the method of multifocal eleсtroretinography in patients with clinically significant macular edema secondary to diabetes mellitus

Методами оптичної когерентної томографії та мультифокальної електороретинографії обстежено 14 пацієнтів (22 ока) з різними видами діабетичного макулярного набряку та 9 здорових осіб (9 очей). Отримані структурні та функціональні результати залежали від вираженості макулярного набряку. Існує пряма залежність між ступенем структурних змін та зниженням біоелектричної активності сітківки, вивченої за допомогою мультифокальної електроретинографії. Поєднання оптичної когерентної томографії та мультифокальної електроретинографії забезпечує додаткові об’єктивні критерії для виявлення та оцінки діабетичного макулярного набряку.Optical coherence tomographic images and multifocal electroretinograms were obtained from 22 eyes of 14 patients with diabetic macular edema and from 9 eyes of 9 normal subjects. The expression of macular edema may influence both anatomic and functional results. Our study revealed a significant direct correlation between the structural disturbances and the reduction of the electric responces from the macular area recorded with the multifocal ERG system. The macular responses recorded with the multifocal ERG system may be a useful tool to evaluate macular function objectively. The combination of OCT and multifocal ERG may provide of objective criteria for the evaluation and assessment of diabetic macular edema

Strategies for the development of cyber-ophthalmology

Background: Making the tertiary management of eye diseases improved and widely available for all social groups in all parts of Ukraine is a pressing challenge for not only the Ministry of Health, but also for the state. Purpose: To provide scientific and theoretical assessment of establishing a new branch of ophthalmology, cyber-ophthalmology. Results: We demonstrated that the studied issue is relevant and important in the light of developments in tele- and cyber-medicine, expansion of application of information technologies to and introduction of artificial intelligence in medicine and in particular in ophthalmology. Conclusion: Cyber-ophthalmology is becoming reality and a systematically important branch of ophthalmology. Research in and developments of this branch are essential for providing tertiary eye disease management and improved disease treatment efficacy for all social groups

Bioengineered Corneas Grafted as Alternatives to Human Donor Corneas in Three High-Risk Patients

Corneas with severe pathologies have a high risk of rejection when conventionally grafted with human donor tissues. In this early observational study, we grafted bioengineered corneal implants made from recombinant human collagen and synthetic phosphorylcholine polymer into three patients for whom donor cornea transplantation carried a high risk of transplant failure. These patients suffered from corneal ulcers and recurrent erosions preoperatively. The implants provided relief from pain and discomfort, restored corneal integrity by promoting endogenous regeneration of corneal tissues, and improved vision in two of three patients. Such implants could in the future be alternatives to donor corneas for high-risk patients, and therefore, merits further testing in a clinical trial

A case of radiation cataract found 29 years after radiation exposure

Background: Radiation cataracts are an acknowledged biological effect of radiation exposure. It has been demonstrated previously that, the mode value for the latent period for the identified post-Chornobyl cases of radiation cataract was 9 years. We present a case of radiation cataract with typical clinical features that manifested 29 years after radiation exposure. Material and Methods: A female patient, born in 1937, worked in the exclusion zone of the Chornobyl Nuclear Power Plant in early May of 1986; she is now under our regular supervision. Because over years, the patient had had the annual routine eye examination (including, but not limited to biomicroscopy, lens examination and red reflex photography using a fundus camera), the time of onset of specific lens opacity could be placed within a period of several months. Results: On examination performed on December 15, 2014, the right lens showed mild peripheral cortical opacity without signs of radiation cataract, and with vacuoli seen in the anterior subcapsular lens region. On examination performed on August 8, 2015, the right eye showed a mild, specific, posterior, central subcapsular opacification. Conclusion: We presented a case of radiation cataract, documented by fundus camera photography, with typical clinical features that manifested 29 years after radiation exposure. Detecting a radiation cataract so late after radiation exposure indicates that the changes in the eye exposed to radiation can be very durable

Intravitreal aflibercept for choroidal neovascularization associated with chorioretinitis: a pilot study

Andrii R Korol,1 Oleksandra Zborovska,2 Taras Kustryn,1 Oleksandra Dorokhova,2 Nataliya Pasyechnikova3 1Laser Department, 2Department of&nbsp;Inflammatory Pathology of the Eye, 3Filatov Institute of Eye Diseases and&nbsp;Tissue Therapy, National Academy of Medical Sciences of Ukraine, Odessa, Ukraine Purpose: The purpose of this study was to evaluate the potential benefits of intravitreal aflibercept injections for the treatment of choroidal neovascularization (CNV) secondary to chorioretinitis.Methods: In this uncontrolled, prospective cohort study, 15 eyes of 14 consecutive patients affected by CNV associated with ocular toxoplasmosis were treated with intravitreal aflibercept (2 mg) pro re nata and observed over a 12-month follow-up period. The primary outcome was the change in best-corrected visual acuity (BCVA) from baseline to month 12. Secondary outcomes included change in central retinal thickness (CRT) in the foveal area on optical coherence tomography (OCT) from baseline to month 12, the number of intravitreal aflibercept injections administered, and safety.Results: Mean (standard deviation [SD]) BCVA improved significantly from 0.36 (0.23) at baseline to 0.64 (0.3) at month 12 (P=0.0002). Mean (SD) CRT on OCT showed a reduction from 317 (74) &micro;m at baseline to 254 (43) &micro;m (P=0.0002) at month 12. A mean (SD) of 1.7 (0.5) injections (range, 1&ndash;2 injections) were performed during the study period. No cases of endophthalmitis, uveitis, stroke, or retinal detachment were noted. No patient demonstrated an intraocular pressure &gt;20 mmHg at any study visit.Conclusion: Intravitreal aflibercept showed a positive clinical effect and was well tolerated for the treatment of CNV associated with chorioretinitis. The results could be helpful for selecting a treatment for CNV secondary to chorioretinitis. Keywords: aflibercept, angiogenesis inhibitors, choroidal neovascularization, central chorioretinitis, anti-VEGF, toxoplasmosi