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2.
Eur J Ophthalmol ; : 11206721241242165, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509758

RESUMO

PURPOSE: The purpose of this paper is to report the increasing incidence of contact-lens related Acanthamoeba keratitis (AK) in a tertiary ophthalmology department in Umbria, central Italy. METHODS: Observational and retrospective case series were carried out. A total of nine eyes with a diagnosis of AK were examined. All patients underwent a full slit lamp examination, in vivo confocal microscopy (IVCM) and corneal scraping. The IVCM was repeated at one and two-week and at one, three and six-month intervals. Samples of domestic tap water were also examined for PCR analysis. Patients were treated with levofloxacin0,5%, Polyhexamethylene biguanide 0.02%, and Propamidine Isetionate0,1%. RESULTS: All patients were contact lens wearers. The average patient age was 27.75 (range 18-45), with three men and five women. The main clinical features were ciliary congestion, diffuse epitheliopathy with punctuated keratitis, multiple, small sub-epithelial, greyish, corneal infiltrates with epithelial defect, pseudodendritic corneal lesions, perineural infiltrates, corneal stromal cellularity, and stromal infiltrates. IVCM was indicative of Acanthamoeba in seven out of the nine eyes. All the positive IVCM images were section images showing double walled, bright-spot cysts with a clear chain-like arrangement of five or more cysts identified in three of the patients. PCR analysis of the water was negative in all cases. CONCLUSION: Although PCR is the most common method used, the increased incidence of AK could mainly be related to a proper IVCM interpretation. A broad-spectrum antibiotic, such as levofloxacin might play a role in the early treatment of AK reducing the virulence of the amoeba.

3.
Br J Ophthalmol ; 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418206

RESUMO

BACKGROUND/AIM: With the popularity of endothelial keratoplasty (EK) procedures, Descemet membrane (DM) EK and pre-Descemet EK, considerable work has been done on understanding the posterior corneal anatomy. Most of the information available relates to the central cornea. We evaluated the peripheral cornea to explore the immunohistological and anatomical relationship between the pre-Descemet layer (PDL), DM and trabecular meshwork (TM). METHODS: Six donor human sclerocorneal discs were studied. PDL, DM and TM were examined by light microscopy, transmission electron microscopy (TEM) and immunohistology. The DM was peeled from the centre to the limit of its peripheral attachment, to reach the transition zone (TZ) between TM and peripheral cornea. Ten-micron sections were stained with antibodies against collagens 1, 2, 3, 4, 5, 6, 12, elastin, myocilin, wnt-1, aquaporin, tenascin C, laminin and integrin alpha 3. RESULTS: Collagens 2, 3, 4, laminin and myocilin were predominantly seen in the TZ between TM and peripheral cornea. Wnt-1, integrin alpha 3 and tenascin C were highly concentrated in TM. Collagen 1 was present predominantly in the corneal stroma. On TEM; DM was thinner with a denser banded structure spread throughout its thickness in the periphery compared with the central cornea where it presents as the distinct anterior banded layer. CONCLUSION: The TZ between DM, PDL and TM shows a unique histological structure at the periphery. The collagen and elastin fibres of the TM are continuous with the PDL. The structures are firmly attached to each other. These findings provide structural information that is relevant to the preparation of DMEK donor tissue.

4.
Br J Ophthalmol ; 107(3): 342-348, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-34610946

RESUMO

PURPOSE: To study the outcome of a modified amnion-assisted conjunctival epithelial redirection (ACER) technique using vacuum-dried amnion (Omnigen) and fibrin glue for managing total limbal stem cell deficiency (LSCD). METHOD: A retrospective, interventional case series of all patients with total LSCD who underwent limbal stem cell transplant (LSCT) using the modified ACER procedure between 2016 and 2019. The outcome was defined as: (1) success: complete corneal re-epithelialisation without conjunctivalisation; (2) partial success: sub-total corneal re-epithelialisation with partial non-progressive conjunctivalisation sparing the visual axis and (3) failure: conjunctivalisation affecting the visual axis. RESULTS: Ten patients (six men), with a mean age of 46.2±18.4 years, were included. The mean follow-up was 23.0±13.9 months. Causes of LSCD were chemical eye injury (30%), congenital aniridia-related keratopathy (30%), ocular surface malignancy (20%), Steven-Johnson syndrome (10%) and contact lens overuse (10%). 50% were bilateral. The time from diagnosis to ACER (for acquired causes) was 45.6±44.4 months. 80% of patients achieved a complete/partial success following ACER and 20% of patients required repeat LSCT. Auto-LSCT was associated with a significantly higher chance of success than allo-LSCT (p=0.048). The mean best-corrected-visual-acuity (logMAR) improved significantly from 1.76±0.64 preoperatively to 0.94±0.94 at final follow-up (p=0.009). Omnigen was available off-the-shelf stored at room temperature and its transparency enabled visualisation of the healing epithelium beneath. CONCLUSION: LSCT using the modified ACER serves as an effective ocular surface reconstruction technique in managing total LSCD and improving vision. Vacuum-dried amnion provides advantages of easy handling, transparency and storage at room temperature.


Assuntos
Doenças da Córnea , Epitélio Corneano , Deficiência Límbica de Células-Tronco , Limbo da Córnea , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , Adesivo Tecidual de Fibrina/uso terapêutico , Âmnio/transplante , Estudos Retrospectivos , Células-Tronco do Limbo , Vácuo , Doenças da Córnea/cirurgia , Doenças da Córnea/patologia , Transplante de Células-Tronco , Epitélio Corneano/patologia
5.
BMJ Open ; 13(5): e065537, 2023 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-37164459

RESUMO

INTRODUCTION: Infectious keratitis (IK) represents the fifth-leading cause of blindness worldwide. A delay in diagnosis is often a major factor in progression to irreversible visual impairment and/or blindness from IK. The diagnostic challenge is further compounded by low microbiological culture yield, long turnaround time, poorly differentiated clinical features and polymicrobial infections. In recent years, deep learning (DL), a subfield of artificial intelligence, has rapidly emerged as a promising tool in assisting automated medical diagnosis, clinical triage and decision-making, and improving workflow efficiency in healthcare services. Recent studies have demonstrated the potential of using DL in assisting the diagnosis of IK, though the accuracy remains to be elucidated. This systematic review and meta-analysis aims to critically examine and compare the performance of various DL models with clinical experts and/or microbiological results (the current 'gold standard') in diagnosing IK, with an aim to inform practice on the clinical applicability and deployment of DL-assisted diagnostic models. METHODS AND ANALYSIS: This review will consider studies that included application of any DL models to diagnose patients with suspected IK, encompassing bacterial, fungal, protozoal and/or viral origins. We will search various electronic databases, including EMBASE and MEDLINE, and trial registries. There will be no restriction to the language and publication date. Two independent reviewers will assess the titles, abstracts and full-text articles. Extracted data will include details of each primary studies, including title, year of publication, authors, types of DL models used, populations, sample size, decision threshold and diagnostic performance. We will perform meta-analyses for the included primary studies when there are sufficient similarities in outcome reporting. ETHICS AND DISSEMINATION: No ethical approval is required for this systematic review. We plan to disseminate our findings via presentation/publication in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42022348596.


Assuntos
Aprendizado Profundo , Ceratite , Humanos , Inteligência Artificial , Projetos de Pesquisa , Tamanho da Amostra , Ceratite/diagnóstico , Metanálise como Assunto , Revisões Sistemáticas como Assunto
6.
Br J Ophthalmol ; 106(6): 786-789, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-33597193

RESUMO

PURPOSE: Pre-Descemet's endothelial keratoplasty (PDEK) donor tissue preparation involves the intrastromal injection of air to create a type 1 big bubble (BB) and avoidance of the creation of a type 2 BB. The purpose of this study was to design and test a technique to consistently creates a type 1 BB without risk of creating a type 2 BB. METHODS: A prospective matched study with 64 human donor sclerocorneal discs, which were not suitable for corneal transplantation, was conducted. The corneas were divided into two groups, of which 32 were subjected to the standard technique of preparing the PDEK donor tissue (group 1, control) and 32 new technique, where in the donor Descemet's membrane was scored with a Sinskey hook. Frequency of occurrence of different types of BB was compared and statistically analysed. RESULTS: With the standard technique (group 1), type 1 BB occurred in 53.1%, type 2 BB in 34.4% and mixed BB in 12.5% of samples. With the scoring technique (group 2), a type 1 BB occurred in 100% of the samples. No type 2 or mixed BB occurred in any case in group 2. The difference in creation of a type 1BB between the two groups was statistically significant (p=0.00). CONCLUSION: The scoring technique is a simple, inexpensive and reproducible option to consistently achieve a type 1 BB to prepare PDEK graft tissue. The next step would be to study the clinical outcomes of PDEK performed with tissue obtained by the scoring technique.


Assuntos
Doenças da Córnea , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior , Córnea , Doenças da Córnea/cirurgia , Lâmina Limitante Posterior/cirurgia , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior/métodos , Endotélio Corneano , Humanos , Estudos Prospectivos , Doadores de Tecidos
7.
Br J Ophthalmol ; 106(8): 1087-1092, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-33687999

RESUMO

PURPOSE: To report the real-world experience of using topical ciclosporin, Ikervis, in the management of ocular surface inflammatory diseases (OSIDs). METHODS: This was a retrospective study of patients treated with Ikervis for OSIDs at the Queen's Medical Centre, Nottingham, between 2016 and 2019. Relevant data, including demographics, indications, clinical parameters, outcomes and adverse events, were collected and analysed for patients who had completed at least 6 months follow-up. For analytic purpose, clinical outcome was categorised as 'successful' (resolved or stable disease), 'active disease' and 'drug intolerance'. RESULTS: 463 patients were included; mean age was 51.1±21.6 years, with a 59.0% female predominance. Mean follow-up was 14.6±9.2 months. The most common diagnosis was dry eye disease (DED; 322, 69.5%), followed by allergic eye disease (AED; 53, 11.4%) and ocular mucous membrane pemphigoid/Steven-Johnson syndrome (OMMP/SJS; 38, 8.2%). Successful treatment was achieved in 343 (74.1%) patients, with 44 (9.5%) requiring additional treatment and 76 (16.4%) reporting drug intolerance. The efficacy of Ikervis was highest in DED (264, 82.0%), followed by OMMP/SJS (25, 65.8%) and post-keratoplasty (7, 50.0%; p<0.001). Logistic regression analysis demonstrated age <70 years (p=0.007), AED (p=0.002) and OMMP/SJS (p=0.001) as significant predictive factors for Ikervis intolerance. AED and post-keratoplasty were 8.16 times (95% CI, 2.78 to 23.99) and 13.98 times (95% CI, 4.22 to 46.28), respectively, more likely to require additional treatment compared with DED. CONCLUSIONS: Ikervis is a useful steroid-sparing topical treatment for managing OSIDs in the real-world setting. Preparations with improved tolerability are needed to benefit a larger number of patients.


Assuntos
Síndromes do Olho Seco , Penfigoide Mucomembranoso Benigno , Síndrome de Stevens-Johnson , Adulto , Idoso , Ciclosporina , Síndromes do Olho Seco/diagnóstico , Síndromes do Olho Seco/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
8.
Br J Ophthalmol ; 105(2): 285-289, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-31488428

RESUMO

AIMS: To describe the in vivo confocal microscopy (IVCM) features of human limbal nerve corpuscles (LNCs) and correlate these with the histological features. METHODS: We examined 40 eyes of 29 healthy living subjects (17 female, 12 male; mean age=47.6) by IVCM. Four limbal quadrants were scanned through all epithelial layers and stroma to identify the LNCs and associated nerves. Ten fresh normal human corneoscleral discs from five deceased patients with a mean age of 67 years and 17 eye-bank corneoscleral rims with a mean age of 57.6 years were stained as whole mounts by the acetylcholinesterase (AChE) method to demonstrate LNCs and corneal nerves. Stained tissue was scanned in multiple layers with the NanoZoomer digital pathology microscope. The in vivo results were correlated to the histological findings. RESULTS: On IVCM, LNCs were identified in 65% of the eyes studied and were mainly (84%) located in the inferior or superior limbal regions. They appeared either as bright (hyper-reflective) round or oval single structures within the hyporeflective, relatively acellular fibrous core of the palisades or were clustered in groups, often located anterior to the palisades of Vogt. They measured 36 µm in largest diameter (range 20-56 µm). The in vivo features were consistent with the histology, which showed LNCs as strongly AChE positive round or oval structures. CONCLUSION: The strong correlation with histology will enable use of IVCM to study LNCs in normal and disease conditions.


Assuntos
Limbo da Córnea/inervação , Microscopia Confocal , Nervo Oftálmico/citologia , Células Receptoras Sensoriais/citologia , Acetilcolinesterase/metabolismo , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/metabolismo , Nervo Oftálmico/metabolismo , Técnicas de Cultura de Órgãos , Células Receptoras Sensoriais/metabolismo , Adulto Jovem
9.
Br J Ophthalmol ; 105(8): 1172-1177, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-32855162

RESUMO

BACKGROUND: Fungal keratitis (FK) is the leading cause of unilateral blindness in the developing world. Antimicrobial peptides (AMPs) have been shown to play an important role on human ocular surface (OS) during bacterial, viral and protozoan infections. In this study, our aim was to profile a spectrum of AMPs in corneal tissue from patients with FK during the active pase of infection and after healing. METHODS: OS samples were collected from patients at presentation by impression cytology and scraping. Corneal button specimens were collected from patients undergoing therapeutic penetrating keratoplasty for management of severe FK or healed keratitis. Gene expression of human beta-defensin (HBD)-1, -2, -3 and -9, S100A7, and LL-37 was determined by quantitative real-time PCR. RESULTS: Messenger RNA expression (mRNA) for all AMPs was shown to be significantly upregulated in FK samples. The levels of HBD-1 and -2 mRNA were found to be elevated in 18/20 FK samples. Whereas mRNA for HBD-3 and S100A7 was upregulated in 11/20 and HBD9 was increased in 15/20 FK samples. LL-37 mRNA showed moderate upregulation in 7/20 FK samples compared with controls. In healed scar samples, mRNA of all AMPs was found to be low and matching the levels in controls. CONCLUSION: AMP expression is a consistent feature of FK, but not all AMPs are equally expressed. HBD-1 and -2 are most consistently expressed and LL-37 the least, suggesting some specificity of AMP expression related to FK. These results will help to identify HBD sequence templates for designing FK-specific peptides to test for therapeutic potential.


Assuntos
Peptídeos Catiônicos Antimicrobianos/genética , Úlcera da Córnea/genética , Infecções Oculares Fúngicas/genética , Regulação da Expressão Gênica/fisiologia , Micoses/genética , Proteína A7 Ligante de Cálcio S100/genética , beta-Defensinas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Úlcera da Córnea/microbiologia , Úlcera da Córnea/cirurgia , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/cirurgia , Feminino , Humanos , Ceratoplastia Penetrante , Masculino , Pessoa de Meia-Idade , Micoses/microbiologia , Estudos Prospectivos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Adulto Jovem , Catelicidinas
10.
Br J Ophthalmol ; 105(3): 328-333, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32580955

RESUMO

BACKGROUND/AIMS: To examine the incidence, causative microorganisms and in vitro antimicrobial susceptibility and resistance profiles of infectious keratitis (IK) in Nottingham, UK. METHODS: A retrospective study of all patients who were diagnosed with IK and underwent corneal scraping between July 2007 and October 2019 (a 12-year period) at a UK tertiary referral centre. Relevant data, including demographic factors, microbiological profiles and in vitro antibiotic susceptibility of IK, were analysed. RESULTS: The estimated incidence of IK was 34.7 per 100 000 people/year. Of the 1333 corneal scrapes, 502 (37.7%) were culture-positive and 572 causative microorganisms were identified. Sixty (4.5%) cases were of polymicrobial origin (caused by ≥2 different microorganisms). Gram-positive bacteria (308, 53.8%) were most commonly isolated, followed by Gram-negative bacteria (223, 39.0%), acanthamoeba (24, 4.2%) and fungi (17, 3.0%). Pseudomonas aeruginosa (135, 23.6%) was the single most common organism isolated. There was a significant increase in Moraxella spp (p<0.001) and significant decrease in Klebsiella spp (p=0.004) over time. The in vitro susceptibilities of Gram-positive and Gram-negative bacteria to cephalosporin, fluoroquinolone and aminoglycoside were 100.0% and 81.3%, 91.9% and 98.1%, and 95.2% and 98.3%, respectively. An increase in resistance against penicillin was observed in Gram-positive (from 3.5% to 12.7%; p=0.005) and Gram-negative bacteria (from 52.6% to 65.4%; p=0.22). CONCLUSION: IK represents a relatively common and persistent burden in the UK and the reported incidence is likely underestimated. Current broad-spectrum antimicrobial treatment provides a good coverage for IK, although challenged by some level of antimicrobial resistance and polymicrobial infection.


Assuntos
Antibacterianos/uso terapêutico , Córnea/microbiologia , Infecções Oculares Bacterianas/epidemiologia , Ceratite/epidemiologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Infecções Oculares Bacterianas/tratamento farmacológico , Infecções Oculares Bacterianas/microbiologia , Feminino , Humanos , Incidência , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Estudos Retrospectivos , Reino Unido/epidemiologia
11.
Br J Ophthalmol ; 104(9): 1304-1309, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31822464

RESUMO

AIM: Non-traumatic corneal perforations (CPerfs) may present with shallow/flat or formed anterior chamber (AC). This study uses anterior segment optical coherence tomography (ASOCT) to ascertain these differences. METHOD: The study included 14 eyes of 13 patients. They underwent high-resolution ASOCT scans at multiple time points, prior to and after cyanoacrylate glueing, between January 2016 and July 2018. A retrospective analysis of over 2500 ASOCT sections and AS photographs was conducted by two independent observers. The findings were correlated with clinical features and diagnoses. RESULT: All patients had documented Seidel's positive sign at the outset. Two groups with distinctive features were identified. In group 1, 'formed' AC, there was hydration of the cornea with lamellar separation of the stroma, intrastromal pockets of fluid, epithelial bullae and an indirect communication between AC and the exterior. In group 2, 'flat' AC, the corneal hydration was less obvious, there were no pockets of intrastromal fluid, no epithelial bullae and a direct communication of the AC with the exterior. After glueing, the stromal hydration resolved, and healing occurred beneath the glue. The glue and corneal blood vessels consistently cast a dense shadow posteriorly on ASOCT. CONCLUSION: ASOCT demonstrates that leaking CPerfs can be indirect or direct. The former is associated with a 'formed' AC and the latter with a very shallow/flat AC. The valvular nature of the communication in indirect perforations allows the AC to maintain its volume despite a continuous leak.


Assuntos
Segmento Anterior do Olho/diagnóstico por imagem , Humor Aquoso/fisiologia , Perfuração da Córnea/diagnóstico por imagem , Perfuração da Córnea/fisiopatologia , Tomografia de Coerência Óptica , Idoso , Idoso de 80 Anos ou mais , Perfuração da Córnea/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adesivos Teciduais/administração & dosagem , Cicatrização
12.
Indian J Ophthalmol ; 66(9): 1239-1250, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30127133

RESUMO

Lamellar keratoplasty (LK) has revolutionized corneal graft surgery in several ways. Deep anterior LK (DALK) has eliminated risk of failure due to endothelial rejection. Endothelial keratoplasty (EK) has almost eliminated induced astigmatism and the "weak" graft-host junction as seen with penetrating keratoplasty (PK) and also reduced the risk of endothelial rejection. LK provided new insights into posterior corneal anatomy that led to better understanding and performance of DALK and to the development of another EK procedure, namely pre-Descemet's EK (PDEK). Surgical procedures for LK were further refined based on the improved understanding and are able to deliver better surgical outcomes in terms of structural integrity and long-term patient satisfaction, reducing the need of further surgeries and minimizing patient discomfort. In most specialist centers, anterior lamellar techniques like DALK and EK techniques like Descemet's stripping EK (DSEK) and Descemet's membrane EK (DMEK) have replaced the full-thickness PK where possible. The introduction of microkeratome, femtosecond laser, and PDEK clamp have made LK techniques easier and more predictable and have led to the innovation of another LK procedure, namely Bowman membrane transplant (BMT). In this article, we discuss the evolution of different surgical techniques, their principles, main outcomes, and limitations. To date, experience with BMT is limited, but DALK has become the gold standard for anterior LK. The EK procedures too have undergone a rapid transition from DSEK to DMEK and PDEK emerging as a viable option. Ultrathin-DSEK may still have a role in modern EK.


Assuntos
Córnea/cirurgia , Doenças da Córnea/cirurgia , Ceratoplastia Penetrante/métodos , Acuidade Visual , Humanos
14.
Br J Ophthalmol ; 102(12): 1646-1652, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29615397

RESUMO

AIMS: To investigate and define the nature of big bubbles (BB) formed by injection of viscoelastic in deep anterior lamellar keratoplasty. METHODS: Intrastromal injections of 0.1 and 0.3 mL of sodium hyaluronate 1.2% and 0.6% were made into sclera-corneal discs (n = 32) at superficial (anterior-third), midstromal (middle-third) and deep (posterior-third) levels to simulate deep anterior lamellar keratoplasty. Postinjection optical coherence tomograms (OCT) were obtained with the needle in situ. The samples were sectioned and examined histologically. Twelve control samples were injected with air. RESULTS: With superficial injections (n=8) only intrastromal accumulation of viscoelastic was noted. With midstromal injections (n=10) intrastromal accumulation of viscoelastic (n=6) and intrastromal big bubbles (IBB) (n=4) with substantial and variable stromal tissue in the walls were noted. No type 1, type 2 or mixed BB were noted. With deep injections (n=14), type 1 BB (n=4), IBB (n=4) and mixed BB (n=6) were obtained.There was no difference in the results with the two different concentrations of viscoelastic used. With air injection (n=12), 10 type 1 and 1 type 2 BB and 1 mixed BB were obtained. No IBB was noted. CONCLUSIONS: BB obtained by injection of viscoelastic and air can be different. The former tends to occur at the site of injection, especially with midstromal injections, takes the form of tissue separation by stretch and tearing and does not cleave in a consistent plane like air. Surgeons should be aware of IBB created by viscodissection and not confuse it for a type1 BB. Intraoperative OCT should help identify IBB.


Assuntos
Ar , Substância Própria/diagnóstico por imagem , Transplante de Córnea/métodos , Ácido Hialurônico/administração & dosagem , Microbolhas , Vacúolos/patologia , Viscossuplementos/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Substância Própria/efeitos dos fármacos , Humanos , Injeções Intraoculares , Pessoa de Meia-Idade , Doadores de Tecidos , Tomografia de Coerência Óptica
16.
Br J Ophthalmol ; 97(4): 438-43, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23390168

RESUMO

PURPOSE: To analyse the efficacy of paired arcuate incisions and compression sutures technique in the management of post penetrating keratoplasty (PK) astigmatism. METHODS: A paired arcuate incision with compression sutures procedure was used to treat 26 eyes with post-PK astigmatism ranging from 6.00 to 16.50 dioptres (D). The incisions were placed at the 7.0 mm optical zone inside the graft-host junction at a depth of 80% of corneal thickness. A 45° paired arc length was planned for eyes with preoperative astigmatism between 6D and 9D, and a 60° paired arc length was planned for eyes with preoperative astigmatism of >9D. At 3 months, corneal topography and refraction was performed and suture(s) removed if indicated. Net and vector astigmatism changes were calculated to determine the efficacy of the procedure. The indications for PK included keratoconus, Fuch's endothelial dystrophy, pseudophakic bullous keratopathy and corneal scar. RESULTS: There was a statistically significant reduction in the mean magnitude of astigmatism from 9.66 ± 2.90D preoperatively to 4.37 ± 2.53D postoperatively in the whole group. The mean decrease in the astigmatism was 4.37 ± 2.05D (58.4%) and 6.23 ± 3.63D (52.6%) in patients with 6-9D and >9D, respectively. Vector power calculations also showed a significant astigmatism reduction in all groups. The safety and efficacy indices were 1.40 and 0.28, respectively. CONCLUSIONS: Manual astigmatic keratotomy is a viable technique with relatively good safety and efficacy outcomes. Based on the results we propose that increasing the arc length to a minimum of 60° for astigmatism of 6-9D, and to 75° for astigmatism >9D, is likely to have a greater beneficial effect.


Assuntos
Astigmatismo/cirurgia , Ceratoplastia Penetrante , Procedimentos Cirúrgicos Oftalmológicos , Complicações Pós-Operatórias , Técnicas de Sutura , Astigmatismo/etiologia , Astigmatismo/fisiopatologia , Topografia da Córnea , Seguimentos , Distrofia Endotelial de Fuchs/cirurgia , Humanos , Ceratocone/cirurgia , Pessoa de Meia-Idade , Refração Ocular/fisiologia , Resultado do Tratamento , Acuidade Visual/fisiologia
17.
Stem Cell Res Ther ; 4(3): 75, 2013 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-23800436

RESUMO

INTRODUCTION: The corneal stroma is being increasingly recognized as a repository for stem cells. Like the limbal and endothelial niches, stromal stem cells often reside in the peripheral cornea and limbus. These peripheral and limbal corneal stromal cells (PLCSCs) are known to produce mesenchymal stem cells in vitro. Recently, a common corneal stromal and epithelial progenitor was hinted at. This study aims to examine the stem cell potential of corneal stromal cells and to investigate their epithelial transdifferentiation ability. METHODS: PLCSCs were grown in traditional Dulbecco modified Eagle medium (DMEM)-based keratocyte culture medium and an M199-based medium and analyzed for a profile of cell-surface markers by using flow cytometry and differentiated into mesenchymal phenotypes analyzed with quantitative polymerase chain reaction (qPCR) and histologic staining. PLCSCs in M199 were subsequently divided into subpopulations based on CD34 and CD105 expression by using fluorescence- activated cell sorting (FACS). Subpopulations were characterized by marker profile and mesenchymal differentiation ability. Both whole PLCSCs and subpopulations were also cultured for epithelial transdifferentiation. RESULTS: Cells cultured in M199 demonstrated a more stem-like cell-surface marker profile, and the keratocyte marker CD34 was retained for several passages but absent in cells cultured in DMEM. Cells cultured in M199 also exhibited a greater mesenchymal differentiation potential, compared with DMEM. PLCSCs could be divided into CD34(+)CD105(+), CD34-CD105(+), and CD34-CD105- subpopulations, of which CD34(+)CD105(+) cells were the most stemlike with regard to marker expression and mesenchymal differentiation potential. Subpopulations of PLCSCs exhibited differing abilities to transdifferentiate into epithelial phenotypes. Cells that were initially CD34(+)CD105(+) showed the greatest differentiation potential, producing CK3(+) and CK19(+) cells, and expressed a range of both epithelial progenitor (HES1, FRZB1, DCT, SOD2, ABCG2, CDH1, KRT19) and terminally differentiated (DSG3, KRT3, KRT12, KRT24) genes. CONCLUSIONS: Culture medium has a significant effect on the phenotype and differentiation capacity of PLCSCs. The stroma contains a heterogeneous cell population in which we have identified CD34(+) cells as a stem cell population with a capacity for mesenchymal and epithelial differentiation.


Assuntos
Córnea/citologia , Células Epiteliais/citologia , Células-Tronco Mesenquimais/citologia , Antígenos CD/metabolismo , Antígenos CD34/metabolismo , Transdiferenciação Celular , Células Cultivadas , Endoglina , Células Epiteliais/metabolismo , Citometria de Fluxo , Expressão Gênica , Humanos , Células-Tronco Mesenquimais/metabolismo , Receptores de Superfície Celular/metabolismo
18.
Invest Ophthalmol Vis Sci ; 53(9): 5109-16, 2012 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-22736610

RESUMO

PURPOSE: Peripheral and limbal corneal stromal cells (PLCSCs), which contain keratocytes, have a complex phenotype. Knowledge of keratocyte cell properties, function, and origin is limited. Evidence available thus far has suggested both mesenchymal stromal and hematopoietic characteristics. Multipotent mesenchymal stromal cells (MSCs) are found in an increasing number of tissues and are the subject of considerable interest and investigation in the disciplines of tissue engineering, immunology, gene therapy, and oncology. METHODS: Isolated PLCSCs were characterized by markers aldehyde dehydrogenase and keratocan, cultured, and analyzed against a set of criteria for the identification of MSCs developed by the International Society of Cellular Therapy (ISCT). PLCSCs were directly compared to fetal liver MSCs (flMSCs). Additional cell surface markers were also used to quantify differentiation, which was also performed on both cell types. RESULTS: PLCSCs were found to be plastic adherent, displayed the correct profile and proportions of CSMs, and demonstrated trilineage potential in accordance with the ISCT guidelines. Furthermore, PLCSCs displayed a high degree of similarity to flMSCs and this likeness extended into the non-ISCT MSC cell surface markers and trilineage differentiation, which were often but not always comparable. CONCLUSIONS: Herein we report a novel observation that PLCSCs conform to all the ISCT criteria and are therefore MSCs. Furthermore, this study has identified the limbal stroma as yet another MSC niche and presents a new perspective on the role of the PLCSC.


Assuntos
Substância Própria/citologia , Células-Tronco Fetais/citologia , Fígado/embriologia , Células-Tronco Mesenquimais/citologia , Aldeído Desidrogenase/metabolismo , Antígenos CD34/metabolismo , Biomarcadores/metabolismo , Adesão Celular , Técnicas de Cultura de Células , Diferenciação Celular , Substância Própria/metabolismo , Células-Tronco Fetais/metabolismo , Citometria de Fluxo , Idade Gestacional , Humanos , Limbo da Córnea/citologia , Células-Tronco Mesenquimais/metabolismo , Fenótipo , Proteoglicanas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
19.
Br J Ophthalmol ; 96(4): 523-9, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22328810

RESUMO

AIM: To describe in vivo confocal microscopy (IVCM) findings in patients with limbal stem cell deficiency (LSCD). METHODS: 23 eyes of 17 consecutive patients suffering from LSCD were included in this study. A detailed examination by IVCM was performed in addition to a routine slit-lamp biomicroscopy. Size and density of corneal epithelial and conjunctival epithelial cells on cornea were measured and statistically analysed using SPSS version 8.0 software. Results were compared with histology in select cases. RESULTS: Anatomical and morphological differences were observed between normal corneal cells and conjunctival epithelial cells on cornea. Size and density differences reached statistically significant levels between the normal corneal cells and the conjunctival epithelial cells on cornea (p<0.01). Goblet cells were visible throughout the conjunctivalised corneal epithelium in eight eyes. Several IVCM features could be correlated with histology in six of our patients. CONCLUSIONS: A number of features were demonstrated by laser IVCM in patients presenting clinically with LSCD. Some of these features were corroborated with features observed on histological examination of tissue samples.


Assuntos
Doenças da Córnea/patologia , Epitélio Corneano/patologia , Limbo da Córnea/patologia , Microscopia Confocal/métodos , Células-Tronco/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Tamanho Celular , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
20.
Br J Ophthalmol ; 96(7): 1034-7, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22611139

RESUMO

AIM: To evaluate the effect of gravity on corneal epithelial cell migration in vitro. METHODS: Fourteen donor peripheral corneoscleral rims were used. Twenty explants were chosen of which 10 were placed vertically and 10 were placed horizontally during culture. Analyses were performed to investigate the effect of gravity on epithelial growth by measuring the extent of epithelial cell growth above and below the horizontal meridian and counting the total number of cells using a haemocytometer. RESULTS: There was no statistically significant difference in cell growth between the explants that were placed horizontally and vertically. However, in the vertical explant group the cells grew preferentially towards the 6 o'clock direction, possibly as a result of gravity. CONCLUSIONS: Gravitational forces may influence cell migration in vitro. This could be of significance in the planning of limbal transplantation, because a superior graft may be more likely to succeed than a gravitationally challenged inferior graft.


Assuntos
Proliferação de Células , Epitélio Corneano/citologia , Gravitação , Limbo da Córnea/citologia , Células-Tronco/citologia , Contagem de Células , Movimento Celular/fisiologia , Células Cultivadas , Humanos , Doadores de Tecidos
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