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1.
Drug Deliv ; 31(1): 2361168, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38899440

RESUMO

Glaucoma is the leading cause of blindness worldwide. However, its surgical treatment, in particular via trabeculectomy, can be complicated by fibrosis. In current clinical practice, application of the drug, Mitomycin C, prevents or delays fibrosis, but can lead to additional side effects, such as bleb leakage and hypotony. Previous in silico drug screening and in vitro testing has identified the known antibiotic, josamycin, as a possible alternative antifibrotic medication with potentially fewer side effects. However, a suitable ocular delivery mechanism for the hydrophobic drug to the surgical site does not yet exist. Therefore, the focus of this paper is the development of an implantable drug delivery system for sustained delivery of josamycin after glaucoma surgery based on crosslinked γ-cyclodextrin. γ-Cyclodextrin is a commonly used solubilizer which was shown to complex with josamycin, drastically increasing the drug's solubility in aqueous solutions. A simple γ-cyclodextrin crosslinking method produced biocompatible hydrogels well-suited for implantation. The crosslinked γ - cyclodextrin retained the ability to form complexes with josamycin, resulting in a 4-fold higher drug loading efficiency when compared to linear dextran hydrogels, and prolonged drug release over 4 days.


Assuntos
Preparações de Ação Retardada , Hidrogéis , Solubilidade , gama-Ciclodextrinas , Hidrogéis/química , gama-Ciclodextrinas/química , Liberação Controlada de Fármacos , Sistemas de Liberação de Medicamentos/métodos , Glaucoma/tratamento farmacológico , Antibacterianos/administração & dosagem , Antibacterianos/química , Antibacterianos/farmacologia , Portadores de Fármacos/química , Animais , Humanos , Reagentes de Ligações Cruzadas/química
2.
Klin Monbl Augenheilkd ; 240(12): 1359-1368, 2023 Dec.
Artigo em Inglês, Alemão | MEDLINE | ID: mdl-38092003

RESUMO

X-ray-based micro-computed tomography (micro-CT) is a largely non-destructive imaging method for the visualisation and analysis of internal structures in the ex vivo eye and affords high resolution. In contrast to other high-resolution imaging methods, micro-CT enables spatial recording of larger and more complex tissue structures, such as the anterior chamber of the eye. Special contrasting methods help to enhance the absorption properties of soft tissue, that is otherwise only weakly radiopaque. Critical point drying (CPD), as primarily used in scanning electron microscopy, offers an additional tool for improving differential contrast properties in soft tissue. In the visualisation of intraosseous soft tissue, such as the efferent lacrimal ducts, sample treatment by decalcification with ethylenediaminetetraacetic acid and subsequent CPD provides good results for micro-CT. Micro-CT can be used for a wide range of questions in 1. basic research, 2. application-related studies in ophthalmology (e.g. evaluation of the preclinical application of microstents for glaucoma treatment or analysis of the positioning of intraocular lenses) but also 3. as a supplement to ophthalmological histopathology.


Assuntos
Oftalmologia , Humanos , Microtomografia por Raio-X/métodos , Imageamento Tridimensional/métodos
3.
Transl Vis Sci Technol ; 12(3): 4, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36857065

RESUMO

Purpose: Microinvasive glaucoma surgery (MIGS) has become an important treatment approach for primary open-angle glaucoma, although the safe and long-term effective lowering of intraocular pressure with currently available implants for MIGS is not yet achieved to a satisfactory extent. The study focusses on the development and in vitro and in vivo testing of a novel microstent for MIGS. Methods: A silicone elastomer-based microstent was developed. Implants were manufactured using dip coating, fs-laser cutting, and spray coating. Within the current study no antifibrotic drug was loaded into the device. Sterilized microstents were analyzed in vitro regarding pressure-flow characteristics and biocompatibility. Six New Zealand white rabbits were implanted with a microstent draining the aqueous humor from the anterior chamber into the subconjunctival space. Drainage efficacy was evaluated using oculopressure tonometry as a transient glaucoma model. Noninvasive imaging was performed. Results: Microstents were manufactured successfully and characterized in vitro. Implantation in vivo was successful for four animals with additional device fixation. Without additional fixation, dislocation of microstents was found in two animals. Safe and effective intraocular pressure reduction was observed for the four eyes with correctly implanted microstent during the 6-month trial period. Conclusions: The described microstent represents an innovative treatment approach for MIGS. The incorporation of a selectively antifibrotic drug into the microstent drug-elutable coating will be addressed in future investigations. Translational Relevance: The current preclinical study successfully provided proof of concept for our microstent for MIGS which is suitable for safe and effective intraocular pressure reduction and offers promising perspectives for the clinical management of glaucoma.


Assuntos
Glaucoma de Ângulo Aberto , Glaucoma , Oftalmologia , Animais , Coelhos , Câmara Anterior , Humor Aquoso
4.
Pharmaceutics ; 15(2)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36839651

RESUMO

One major complication after fistulating glaucoma surgeries are fibroblast-mediated scarring processes and their specific prevention is key in the development of novel pharmaceutical concepts. Within this study a possible antifibrotic potential of kitasamycin (KM) in a transforming growth factor (TGF)-ß1-mediated fibroblast model was evaluated in vitro. Primary ocular fibroblasts were isolated, cultivated and a dose-response test including determination of the half maximal effective concentration (EC50) for KM was conducted. Transformation of fibroblasts into myofibroblasts was induced by TGF-ß1and immunofluorescence (IF), and Western blot (WB) analyses were performed with fibroblasts and myofibroblasts. IF analyses were carried out using antibodies against α-smooth muscle actin (α-SMA) and fibronectin, and protein detection of intracellular and extracellular proteins was performed by WB. Using the dose-response test, the viability, cytotoxicity and EC50 of KM after 24 and 48 h were determined. Fibroblasts exposed to various KM concentrations showed no increase in α-SMA and extracellular matrix expression. In TGF-ß1-stimulated myofibroblasts, KM inhibited the expression of α-SMA and fibronectin in a concentration-dependent manner. These findings demonstrate that KM could impair the transformation of fibroblasts into myofibroblasts and the expression of proteins involved in fibrotic processes, representing a potential agent for specific fibrosis prevention in future therapeutic concepts.

5.
CPT Pharmacometrics Syst Pharmacol ; 12(3): 288-299, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36708082

RESUMO

Good eyesight belongs to the most-valued attributes of health, and diseases of the eye are a significant healthcare burden. Case numbers are expected to further increase in the next decades due to an aging society. The development of drugs in ophthalmology, however, is difficult due to limited accessibility of the eye, in terms of drug administration and in terms of sampling of tissues for drug pharmacokinetics (PKs) and pharmacodynamics (PDs). Ocular quantitative systems pharmacology models provide the opportunity to describe the distribution of drugs in the eye as well as the resulting drug-response in specific segments of the eye. In particular, ocular physiologically-based PK (PBPK) models are necessary to describe drug concentration levels in different regions of the eye. Further, ocular effect models using molecular data from specific cellular systems are needed to develop dose-response correlations. We here describe the current status of PK/PBPK as well as PD models for the eyes and discuss cellular systems, data repositories, as well as animal models in ophthalmology. The application of the various concepts is highlighted for the development of new treatments for postoperative fibrosis after glaucoma surgery.


Assuntos
Farmacologia em Rede , Farmacologia , Animais , Modelos Biológicos , Preparações Farmacêuticas , Farmacologia/métodos
6.
Quant Imaging Med Surg ; 12(9): 4361-4376, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36060579

RESUMO

Background: Micro-computed tomography (micro-CT) provides detailed 3-dimensional (3D) visualization of anatomical structures and encourages morphological reinvestigation of organs with delicate features. The low radiodensity of soft tissues necessitates preceding sample preparation to conduct X-ray imaging with decent contrast between different tissues. In this study, we demonstrate the preparation with three radiopaque agents in combination with elimination of liquids by critical point drying (CPD) introduced for ocular samples. Methods: Enucleated porcine eyes were prepared with ethanolic iodine (EI), aqueous iodine-potassium iodide, or ethanolic phosphotungstic acid (EPTA). Micro-CT scans of the samples were conducted in a moist environment with an isotropic resolution of 9.2-12.5 µm voxel size. Subsequently, samples were chemically dehydrated and critical point (CP) dried to conduct a second scan in a dry environment with a resolution up to 4.7-5.4 µm in voxel size. The visualization effects were qualitatively and semi-quantitatively evaluated with regard to the generated contrast between different ocular tissues. Results: All three contrast agents accumulated well in most of the investigated ocular tissues and lead to an increased X-ray attenuation which allowed for differentiated visualization of ocular structures. Problematic agent penetration into the lens was obvious for iodine-potassium iodide and EPTA. Artificial damages of the lens and thickness reduction for the cornea and sclera due to CPD were noticed. The effects of the different contrasting treatments are described and compared with regard to the effects of CPD. Exclusively CP dried samples that were not treated with contrast agents could also be visualized excellently with a good distinction of different ocular structures from each other. Conclusions: All ocular structures can be visualized by micro-CT. To contrast moist samples, the best results were achieved with iodine potassium iodide (IPI). CPD improved the scan quality in all cases. Even without pretreatment with contrasting agents, the CP dried samples showed a contrast similar to the IPI treated samples.

7.
Diagnostics (Basel) ; 11(11)2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34829356

RESUMO

The aim of this study was to analyze the use of the diagnostic B-scan ultrasound. Should it be made accessible to all surgical centers in Sub-Saharan Africa in order to (i) avoid unnecessary cataract surgery and (ii) evaluate extraocular pathology? This study was conducted in Kinshasa from 2006 to 2019. Three hundred and twenty-three patients were included and separated into two groups. Group 1 included 262 patients with dense cataract. Group 2 consisted of 61 patients with pathologies of the ocular adnexa, and all were examined with a B-scan ultrasound. In group 1, there were 437 systematically screened eyes. Three hundred and ninety-eight eyes (91.08%) showed no abnormalities, 13 (2.97%) retinal detachments were identified, and 15 (3.43%) demonstrated a detached posterior hyaloid membrane. In the second group, 61 patients were examined (group 2). In 20 of them, surgery was performed for biopsy, tumor excision, mucoceles drainage, and palliative treatment. The need for routine B-scan examinations in dense cataract patients seems to be limited and can most likely be replaced by a thorough application of locally available examination techniques. B-scan application is recommended to manage orbital patients in the most cost-effective way.

8.
Int J Ophthalmol ; 14(9): 1392-1395, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34540615

RESUMO

AIM: To assess the retinal function in patients with dense cataracts in resource poor settings in Kinshasa, DR Congo. METHODS: In a tertiary eye care center, the Purkinje entoptic test was performed as part of the ophthalmological examination in 98 eyes in patients with cataract, using a penlight. Totally 92 cataract patients including 86 patients suffered from unilateral and 6 from bilateral cataracts were included in the study. The investigator asked the patients about their perception of the vascular pattern most commonly described as a leafless or dead tree. Visual acuity≥6/60 was considered an indication of good visual function and visual acuity<6/60 of poor function. Following small incision cataract surgery, best corrected visual acuity (BCVA) was determined and compared with the preoperative findings. RESULTS: Out of 98 eyes, there were 80 (81.6%) where the Purkinje entoptic phenomenon was reported by the patients. After cataract surgery, out of the 80 eyes, there were 75 (93.8%) with a BCVA of better than 6/60, whereas in 5 eyes (6.2%), BCVA was 6/60 or less. Out of the 18 eyes (18.4%) where no Purkinje tree was recognized, there were 14 (77.8%) with BCVA of better than 6/60, whereas in 4 (22.2%) BCVA was 6/60 or less. CONCLUSION: The Purkinje entoptic test is successfully used for preoperative assessment of retinal function in patients with dense cataract. However, further investigation and refinement of the test is necessary to validate the method for use in sub-Saharan conditions.

9.
Quant Imaging Med Surg ; 11(7): 3029-3041, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34249632

RESUMO

BACKGROUND: The development of presbyopia is correlated with increased lens stiffness. To reveal structural changes with age, ultrahigh field magnetic resonance imaging (UHF-MRI) was used to analyze water diffusion in differently aged human lenses ex vivo. METHODS: After enucleation lens extractions were performed. Lenses were photographed, weighed, and embedded in 0.5% agarose dissolved in culture medium. UHF-MRI was conducted to analyze anatomical characteristics of the lens using T2-weighted Turbo-RARE imaging and to obtain apparent diffusion coefficients (ADC) measurements. A Gaussian fit routine was used to examine the ADC histograms. RESULTS: An age-dependent increase in lens wet weight, lens thickness, and lens diameter was found (P<0.001). T2-weighted images revealed a hyperintense lens cortex and a gradually negative gradient in signal intensity towards the nucleus. ADC histograms of the lens showed bimodal distributions (lower ADC values mainly located in the nucleus and higher ADC values mainly located in the cortex), which did not change significantly with age [ßPeak1=1.96E-7 (-20E-7, 10E-7), P=0.804 or ßPeak2=15.4E-7 (-10E-7, 40E-7), P=0.276; respectively]. CONCLUSIONS: Clinically relevant age dependent lens hardening is probably not correlated with ADC changes within the nucleus, which could be confirmed by further measurements.

10.
Quant Imaging Med Surg ; 11(5): 1737-1750, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33936961

RESUMO

BACKGROUND: Regarding the growing interest and importance of understanding the cellular changes of the cornea in diseases, a quantitative cellular characterization of the epithelium is becoming increasingly important. Towards this, the latest research offers considerable improvements in imaging of the cornea by confocal laser scanning microscopy (CLSM). This study presents a pipeline to generate normative morphological data of epithelial cell layers of healthy human corneas. METHODS: 3D in vivo CLSM was performed on the eyes of volunteers (n=25) with a Heidelberg Retina Tomograph II equipped with an in-house modified version of the Rostock Cornea Module implementing two dedicated piezo actuators and a concave contact cap. Image data were acquired with nearly isotropic voxel resolution. After image registration, stacks of en-face sections were used to generate full-thickness volume data sets of the epithelium. Beyond that, an image analysis algorithm quantified en-face sections of epithelial cells regarding the depth-dependent mean of cell density, area, diameter, aggregation (Clark and Evans index of aggregation), neighbor count and polygonality. RESULTS: Imaging and cell segmentation were successfully performed in all subjects. Thereby intermediated cells were efficiently recognized by the segmentation algorithm while efficiency for superficial and basal cells was reduced. Morphological parameters showed an increased mean cell density, decreased mean cell area and mean diameter from anterior to posterior (5,197.02 to 8,190.39 cells/mm2; 160.51 to 90.29 µm2; 15.9 to 12.3 µm respectively). Aggregation gradually increased from anterior to posterior ranging from 1.45 to 1.53. Average neighbor count increased from 5.50 to a maximum of 5.66 followed by a gradual decrease to 5.45 within the normalized depth from anterior to posterior. Polygonality gradually decreased ranging from 4.93 to 4.64 sides of cells. The neighbor count and polygonality parameters exhibited profound depth-dependent changes. CONCLUSIONS: This in vivo study demonstrates the successful implementation of a CLSM-based imaging pipeline for cellular characterization of the human corneal epithelium. The dedicated hardware in combination with an adapted image registration method to correct the remaining motion-induced image distortions followed by a dedicated algorithm to calculate characteristic quantities of different epithelial cell layers enabled the generation of normative data. Further significant effort is necessary to improve the algorithm for superficial and basal cell segmentation.

11.
Biosci Rep ; 40(10)2020 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-33026069

RESUMO

PURPOSE: Confocal laser scanning microscopy (CLSM) is a non-invasive technique for cellular in vivo imaging of the human cornea. CLSM screening was evaluated for early detection of corneal nerve morphology changes and neuropathogenic events in different stage multiple myeloma (MM) patients. As MM patients show disease as well as therapy-related neuropathological symptoms, CLSM potentially provides a tool for non-invasive early detection of neuropathogenic events. CLSM findings were compared with the severity of peripheral neuropathic (PNP) symptoms. METHODS: The study enrolled 25 MM patients in which bilateral ophthalmologic examination was performed including unilateral CLSM. Further peripheral nerve function was clinically evaluated using the conventional neuropathy symptom and neuropathy deficit scores (NDSs). RESULTS: In 18/25 MM patients, CLSM detected atypical morphological appearance of bulb-like enlarged nerve endings in the corneal sub-basal nerve plexus. These neuromas were only found in patients showing moderate to severe PNP, in patients with mild or lacking PNP neuromas were absent. CONCLUSIONS: CLSM provides a novel non-invasive diagnostic tool for identification of neuromas in cancer patients affected by therapy or disease-related neuropathologies, perspectival allowing early neuronal degenerative process detection and monitoring.


Assuntos
Córnea/inervação , Microscopia Confocal , Mieloma Múltiplo/patologia , Nervo Óptico/patologia , Neurite Óptica/patologia , Papiledema/patologia , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/complicações , Neurite Óptica/etiologia , Papiledema/etiologia , Valor Preditivo dos Testes
12.
R Soc Open Sci ; 7(9): 200441, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33047019

RESUMO

To elucidate and to inhibit post-surgical fibrotic processes after trabeculectomy in glaucoma therapy, we measured gene expression in a fibrotic cell culture model, based on transforming growth factor TGF-ß induction in primary human tenon fibroblasts (hTFs), and used Connectivity Map (CMap) data for drug repositioning. We found that specific molecular mechanisms behind fibrosis are the upregulation of actins, the downregulation of CD34, and the upregulation of inflammatory cytokines such as IL6, IL11 and BMP6. The macrolide antibiotic Josamycin (JM) reverses these molecular mechanisms according to data from the CMap, and we thus tested JM as an inhibitor of fibrosis. JM was first tested for its toxic effects on hTFs, where it showed no influence on cell viability, but inhibited hTF proliferation in a concentration-dependent manner. We then demonstrated that JM suppresses the synthesis of extracellular matrix (ECM) components. In hTFs stimulated with TGF-ß1, JM specifically inhibited α-smooth muslce actin expression, suggesting that it inhibits the transformation of fibroblasts into fibrotic myofibroblasts. In addition, a decrease of components of the ECM such as fibronectin, which is involved in in vivo scarring, was observed. We conclude that JM may be a promising candidate for the treatment of fibrosis after glaucoma filtration surgery or drainage device implantation in vivo.

13.
Klin Monbl Augenheilkd ; 237(9): 1117-1123, 2020 Sep.
Artigo em Inglês, Alemão | MEDLINE | ID: mdl-32967033

RESUMO

BACKGROUND: Glaucoma is one of the most common causes of blindness worldwide. The only evidence-based treatment to slow down the progression of glaucoma is the reduction of intraocular pressure (IOP) using local medication or through surgery. During the last years, a large number of microinvasive glaucoma surgery techniques (MIGS) has been developed, in order to reduce the IOP in glaucoma patients safely and effectively. Until now, efficacy of MIGS has been assessed mainly according to the postoperative IOP and the number of medications used. Results from long-term studies are rare or not available in the majority of the cases. In order to better evaluate the functionality of MIGS, a new examination method has been developed with the help of a new oculopressor device. In this study the efficacy of different MIGS techniques will be examined using the new oculopressor. MATERIAL/METHODS: At first, glaucoma patients that had previously received a MIGS surgery (iStent inject, XEN Stent, ELT) were examined with the new oculopression test. Their results were compared with those of non-operated patients and healthy individuals. Overall, 38 healthy subjects (group 1), 10 non-operated patients (group 2), 19 patients after iStent inject implantation (group 3), 14 patients after XEN Stent implantation (group 4) and 5 patients after ELT (group 5) were examined. The new examination measures the IOP-reduction that occurs after oculopression and can be seen as an indirect measurement of the outflow facility of the eye. RESULTS: The IOP-reduction after oculopression differed among the study groups. Non-operated patients showed a significantly lower IOP-reduction compared to healthy individuals. Patients after iStent inject and XEN stent implantation showed a larger reduction of IOP after oculopression in relation to non-operated patients and their results approximated those of healthy individuals. These patients needed fewer medications postoperatively in relation to non-operated patients. Patients after ELT showed postoperatively a smaller reduction of IOP after oculopression compared to iStent inject and XEN stent patients. CONCLUSION: MIGS can increase the outflow facility of the eye in patients with glaucoma. Though ELT had the lowest impact on the aqueous outflow among the studied procedures in this study. The new test can help in the evaluation of current and further development of new MIGS in the future.


Assuntos
Glaucoma de Ângulo Aberto , Glaucoma/cirurgia , Teste de Esforço , Humanos , Pressão Intraocular , Stents , Resultado do Tratamento
14.
Int J Clin Pract ; 74(10): e13588, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32562301

RESUMO

OBJECTIVES: Monovision is a method of correcting presbyopia where one eye is focused for far and the other for near vision. It is a simple, cost-effective approach to overcome the loss of accommodation with age and to become spectacles independent. METHODOLOGY: About 50 patients, where bilateral cataract extraction was indicated, were included in this study performed at the St. Joseph's Eye Hospital in Kinshasa (DR Congo). Small incision cataract surgery technique (SICS) was applied with the implantation of 6 mm PMMA lenses in the capsular bag. IOL refractive power choice was made to achieve a post-operative refraction of -0.5 dpt for the eye selected for far vision. The second eye received an implant heading for a post-operative myopia of -1.5 dpt suitable for intermediated and near vision. According to the literature, monovision criteria have been regarded as fulfilled when (a) far vision was 0.5 (logMAR) or better and (b) near vision was P3 (0.40, Decimal 32 cm) or better. Spectacle dependence after bilateral cataract surgery heading for monovision was analysed using a dedicated questionnaire. RESULTS: Out of all 50 patients 22 (44%) fulfilled the above defined criteria of monovision in terms of post-operative refraction and visual acuity. About 19 out of these 22 (86.3%) patients were happy without glasses. Two of them used bifocal spectacles, whereas the remaining patient refused spectacles. About 28 patients did not fulfill monovision criteria. Out of these 28 patients, however, 9 (32.1%) of them are happy without glasses. CONCLUSION: In view of the described local circumstances aiming for monovision after bilateral cataract surgery is a suitable approach to optimise cataract surgical outcomes with no extra costs for surgery but considerable improvement of patient's visual performance in daily life.


Assuntos
Extração de Catarata/métodos , Implante de Lente Intraocular/métodos , Acuidade Visual/fisiologia , Catarata/terapia , República Democrática do Congo , Óculos/estatística & dados numéricos , Feminino , Humanos , Lentes Intraoculares/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Visão Monocular
15.
Afr Health Sci ; 20(4): 1817-1827, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34394244

RESUMO

INTRODUCTION: The leading cause of childhood blindness globally is paediatric cataract. Bilateral cataract surgery can help to improve visual performance and to diminish the burden of childhood blindness. OBJECTIVE: To report in a retrospective observational cohort study the long-term outcomes of 298 children who had bilateral cataract surgery with IOL implantation from 2001-2016 in Kinshasa. METHODS: A standardized surgical treatment of paediatric cataract was practiced on 298 children. Patient's follow-up, complications, and visual outcomes were recorded and analysed. RESULTS: The mean age was 5.7 ± 4.3 years and males were predominant (64.9%). Most of children were living mainly in urban poorest areas (96.3%). Strabismus, nystagmus and microcornea were encountered in 20.1%, 25.1% and 8.7% of children, respectively. Using WHO criteria most of patients were classified as blind preoperatively and 81.9% of them had improved visual outcomes after surgery. Main reasons for reduced vision during follow-up were secondary cataract (5.7%), IOL decentration (1.2%), retinal detachment (1.2%), and secondary glaucoma (1.5%). CONCLUSION: In spite of the post conflict challenges, elimination of cataract blindness in children remains a priority. Children present at a late age for surgery and long term follow-up is poor. There is need for program strengthening in these areas.


Assuntos
Cegueira/etiologia , Extração de Catarata , Catarata/diagnóstico , Glaucoma/etiologia , Baixa Visão/etiologia , Criança , Pré-Escolar , Estudos de Coortes , República Democrática do Congo , Feminino , Seguimentos , Humanos , Masculino , Estudos Retrospectivos , Resultado do Tratamento
16.
Klin Monbl Augenheilkd ; 236(12): 1428-1434, 2019 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-31805595

RESUMO

BACKGROUND: The long-term success of fistulating therapies for the treatment of glaucoma is essentially limited by excessive scarring reactions (fibrosis). Cytostatic agents such as mitomycin C can prevent fibrosis, but are often associated with side effects. Specific antifibrotics are not currently in clinical use. Therefore, this study describes a systems biology approach using a dedicated bioinformatics technology platform, with which active substances can be identified and repositioned as antifibrotics. MATERIALS AND METHODS: Differential gene expression data of human Tenon fibroblasts (hTF) were collected from untreated hTF and from hTF stimulated with TGF-ß1 ("fibrotic fibroblasts") by next-generation sequencing (NGS) and were used as the basis for the drug identification process. These data were filtered with the bioinformatic tool "FocusHeuristics". In comparison with the Connectivity Map database, antifibrotic agents were identified. The evaluation of a potentially promising drug as an antifibrotic was performed at hTF by indirect immunofluorescence in vitro. RESULTS: The analysis of the gene expression data led to the identification of several interaction networks of genes or proteins involved in fibrotic processes. One of these networks contains the cytokine bone morphogenic protein 6 (BMP6), interleukin 6 (IL6) and fibroblast growth factor 1 (FGF1). Another relevant network has been identified around the cluster of differentiation 34 (CD34) gene. The comparison of these data with those of the Connectivity Map allowed the identification of an inhibitory drug. Its evaluation in the fibrotic cell culture model in vitro using indirect immunofluorescence led to a significant reduction in the expression of the fibrotic marker proteins fibronectin and alpha-smooth muscle actin (α-SMA), which confirmed the predicted antifibrotic effect. CONCLUSION: Systems biological approaches can be used for the identification of antifibrotic drug candidates for the prevention of postoperative fibrosis and should be transferable by the investigating differential gene expression data of further ocular cells or tissues to other ophthalmological fields of application.


Assuntos
Fibrose , Procedimentos Cirúrgicos Oftalmológicos , Oftalmologia , Biologia de Sistemas , Actinas , Fibroblastos , Fibrose/etiologia , Fibrose/prevenção & controle , Humanos , Mitomicina , Procedimentos Cirúrgicos Oftalmológicos/efeitos adversos , Complicações Pós-Operatórias
17.
Middle East Afr J Ophthalmol ; 26(2): 83-88, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31543665

RESUMO

PURPOSE: The purpose of this study is to describe the methodology and to assess the effectiveness of a community-based rehabilitation (CBR) program to identify and refer children with blinding cataract for the management and surgery to reduce the burden of childhood blindness due to cataract in Kinshasa. METHODS: Church-based volunteers were trained to identify children with presumed eye disorders in their localities and households and to refer them for cataract identification by an ophthalmic nurse during parishes' visits. Volunteers were parishioners living in the quartiers where identification took place and worked as community workers with the CBR program. Nurses used a lamp-torch to rule out cataract. Selected children were referred to the tertiary eye health facility at St Joseph Hospital for diagnosis and management. RESULTS: Identification took place in 31 out of 165 parishes in the Archdioceses of Kinshasa from 2000 to 2016 and 11,106 children aged <16 years were screened. Among them, 1277 children (11.5%) were presumed to have cataract. Ninety-two children among them died before surgery; 107 children were lost to further follow-up and did not report to the CBR center for referral. Reasons given were change of home address, moving in their lieu of origin, death, and refusal of treatment by the parents. Finally, only 1078 children were referred to the pediatric ophthalmologist and 705 children (65.4%) were definitively diagnosed to have treatable cataract, while in 373 children (34.6%), cataract surgery was not indicated for several reasons. There was a positive history of familial cataract in 36 children (2.8%). CONCLUSION: Using church-based volunteers and ophthalmic nurses during community screening proved efficient in the identification and referral of pediatric cataract. Keeping regular identification activities in the community and maintaining high-quality and accessible pediatric cataract surgery services can help to clear up the backlog of cataract blind children.


Assuntos
Extração de Catarata , Catarata/diagnóstico , Serviços de Saúde Comunitária/organização & administração , Organizações Religiosas/organização & administração , Encaminhamento e Consulta/organização & administração , Adolescente , Cegueira/prevenção & controle , Catarata/terapia , Criança , Pré-Escolar , Estudos Transversais , República Democrática do Congo , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pediatria , Voluntários
18.
Biosci Rep ; 39(5)2019 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-30967499

RESUMO

We aimed to identify differences in cytokine/chemokine levels in the aqueous humor (AH) of primary open-angle glaucoma (POAG) patients who suffered from scarring, compared with POAG patients with no scarring after trabeculectomy surgery. Identification of differently expressed cytokines and chemokines may help to understand scarring and fibrotic processes following trabeculectomy, and to make predictions for the outcome of fistulating surgery in the future. Furthermore, the identification of cell signaling pathways involved in fibrosis offers the opportunity for a more specific antifibrotic therapy with reduced side effects, and an improvement in long-term surgical outcome.Eight samples of AH were collected during trabeculectomy surgery and commercially available cytokine/chemokine arrays were used. Specific, differently expressed proteins (cytokines/chemokines) in AH samples from patients with positive and negative surgery outcomes were detected. These proteins were classified based on their known profibrotic, inflammatory, adhesive, and apoptotic properties. Transforming growth factor ß (TGF-ß) and vascular endothelial growth factor (VEGF) were among the most important profibrotic cytokines that we detected. Differences in the fold change of protein expression were highly significant between patients after successful and failed trabeculectomy surgery, and these were processed and visualized using ExprEssence software.This pilot study revealed differences in concentrations of cytokines/chemokines in AH between the two examined groups of patients. Our findings suggest that a positive outcome from trabeculectomy is strongly related to an inhibition of the fibrosis process.


Assuntos
Quimiocinas/genética , Citocinas/genética , Glaucoma de Ângulo Aberto/cirurgia , Trabeculectomia/efeitos adversos , Adolescente , Adulto , Idoso , Humor Aquoso/metabolismo , Criança , Feminino , Glaucoma de Ângulo Aberto/genética , Glaucoma de Ângulo Aberto/metabolismo , Glaucoma de Ângulo Aberto/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Fator de Crescimento Transformador beta/genética , Fator A de Crescimento do Endotélio Vascular/genética
19.
Case Rep Ophthalmol Med ; 2018: 5010915, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30402316

RESUMO

An early developmental lack of the optic vesicle can result in congenital anophthalmia, defined as a complete absence of the eye, which can be distinguished from congenital microphthalmos, where ocular rudiments are present. Here, a rare pediatric case of congenital clinical anophthalmos with orbital cyst in the left orbit is reported. The patient was a 14-month-old girl with no other congenital defects who underwent surgical and prothetic management in St. Joseph's Hospital Kinshasa, Democratic Republic of the Congo (DRC). Surgery was carried out under general anesthesia. The cyst was punctured and its wall fully excised. Near the orbital apex pigmented elements representing iris, ciliary body, and choroidal or retinal remnants were found. The specimens were fixed in formalin for histological examination. Surgical cyst removal including socket deepening for an artificial eye was performed. Postoperative wound healing was uneventful and a satisfactory cosmetic outcome was achieved in all follow-up examinations. Histological examination revealed rudimentary ocular structures similar to degenerated lens tissue with a typical, PAS-positive capsule. Additionally, pigmented epithelial structures, which seem to be of ciliary body, iris, and choroidal or retinal-type epithelium origin, could be detected, prompting the final diagnosis, microphthalmia with dominant cyst formation.

20.
Case Rep Ophthalmol Med ; 2018: 8461737, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29805827

RESUMO

Carcinoma of the conjunctiva is a malignant tumor which is mostly detected and surgically treated at an early stage because of medical or cosmetic problems. Exceptions of this rule may occur in developing countries, where patients do not have access to standard medical care systems. We report the case of a conjunctival carcinoma in an African patient with an unusually late presentation. Because of local medical shortcomings, and considering the severe, transmural inflammation of anterior ocular structures, an exenteration was performed although the orbit was not deeply involved with the tumor. The strong nuclear expression of p53 indicates a major role of UV exposure in this case. A total of 16-month follow-up in this patient and larger published series suggest that the risk of metastasis is rather low under those circumstances, even with invasive tumors.

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