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2.
Ophthalmology ; 121(7): 1377-82, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24576886

RESUMO

PURPOSE: To investigate the efficacy and safety of corneal collagen cross-linking (CXL) with photoactivated riboflavin (photoactivated chromophore for infectious keratitis [PACK]-CXL) in the management of infectious keratitis with corneal melting. DESIGN: Prospective clinical trial. PARTICIPANTS: Forty eyes from 40 patients with advanced infectious keratitis and coexisting corneal melting. METHODS: Twenty-one patients (21 eyes) underwent PACK-CXL treatment in addition to antimicrobial therapy. The control group consisted of 19 patients (19 eyes) who received only antimicrobial therapy. MAIN OUTCOME MEASURES: The slit-lamp characteristics of the corneal ulceration, corrected distance visual acuity, duration until healing, and complications were documented in each group. The Mann-Whitney U test was used for statistical analysis. P values less than 0.05 were considered statistically significant. RESULTS: The average time until healing was 39.76 ± 18.22 days in the PACK-CXL group and 46.05 ± 27.44 days in the control group (P = 0.68). After treatment and healing, corrected distance visual acuity was 1.64 ± 0.62 in the PACK-CXL group and 1.67 ± 0.48 in the control group (P = 0.68). The corneal ulceration's width and length was significantly bigger in the PACK-CXL group (P = 0.004 and P = 0.007). Three patients in the control group demonstrated corneal perforation; infection recurred in 1 of them. No serious complications occurred in the PACK-CXL group. CONCLUSIONS: Corneal CXL with photoactivated riboflavin did not shorten the time to corneal healing; however, the complication rate was 21% in the control group, whereas there was no incidence of corneal perforation or recurrence of the infection in the PACK-CXL group. These results indicate that PACK-CXL may be an effective adjuvant therapy in the management of severe infectious keratitis associated with corneal melting.


Assuntos
Colágeno/metabolismo , Úlcera da Córnea/tratamento farmacológico , Reagentes de Ligações Cruzadas/uso terapêutico , Infecções Oculares/tratamento farmacológico , Fármacos Fotossensibilizantes/uso terapêutico , Riboflavina/uso terapêutico , Adulto , Antibacterianos/uso terapêutico , Substância Própria/metabolismo , Úlcera da Córnea/metabolismo , Úlcera da Córnea/microbiologia , Infecções Oculares/metabolismo , Infecções Oculares/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo , Resultado do Tratamento , Raios Ultravioleta , Acuidade Visual/fisiologia
3.
Int Ophthalmol ; 34(4): 951-5, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24249457

RESUMO

To report the clinical presentation, progress and management of atypical acute hydrops. A retrospective case study of three patients with keratoconus, two of whom had previously undergone penetrating keratoplasty. The patients underwent full ophthalmological examination and digital slit-lamp imaging of the cornea throughout the course of the condition. The two patients who had previously undergone keratoplasty had spontaneous hydrops primarily affecting the host bed but in one case extended to the graft inferiorly; however, in the third patient it was traumatic in origin. The Descemet's tear affected the host rim in only one patient, which resolved spontaneously. In another patient, the hydrops was related to an internal dehiscence of the graft-host junction and had to be managed by an endothelial transplant covering the dehisced graft-host junction. In the third patient, hydrops secondary to trauma was also associated with acute haemops. Progression of keratoconus post keratoplasty can occur exclusively in the recipient bed leading to acute hydrops in the host sparing the transplanted cornea. The progressive thinning and ectasia of the recipient bed can also result in internal graft-host dehiscence leading to chronic oedema. Rapid entry of aqueous or blood cells into the corneal stroma following acute rupture of the Descemet's membrane suggests that the abnormal stroma of the eye with keratoconus may have an important role to play in the pathogenesis of acute hydrops/haemops.


Assuntos
Edema da Córnea/patologia , Ceratocone/patologia , Doença Aguda , Traumatismos Oculares/complicações , Feminino , Humanos , Ceratoplastia Penetrante/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
4.
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.

5.
Front Med (Lausanne) ; 11: 1393832, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39206175

RESUMO

Background: To compare the diagnostic performance of microbiological culture and 16S/18S rRNA gene polymerase chain reaction (PCR)-Sanger sequencing for infectious keratitis (IK) and to analyse the effect of clinical disease severity on test performance and inter-test concordance. Methods: This was a three-arm, diagnostic cross-sectional study. We included all eligible patients who presented with presumed bacterial/fungal keratitis to the Queen's Medical Centre, Nottingham, UK, between June 2021 and September 2022. All patients underwent simultaneous culture (either direct or indirect culture, or both) and 16S (pan-bacterial)/18S (pan-fungal) ribosomal RNA (rRNA) PCR-Sanger sequencing. The bacterial/fungal genus and species identified on culture were confirmed using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. Relevant clinical data were also collected to analyze for any potential clinico-microbiological correlation. Main outcome measures included the diagnostic yield, test accuracy (including sensitivity and specificity), and inter-test agreement [including percent agreement and Cohen's kappa (k)]. Results: A total of 81 patients (86 episodes of IK) were included in this study. All organisms identified were of bacterial origin. Diagnostic yields were similar among direct culture (52.3%), indirect culture (50.8%), and PCR (43.1%; p = 0.13). The addition of PCR enabled a positive diagnostic yield in 3 (9.7%) direct culture-negative cases. Based on composite reference standard, direct culture had the highest sensitivity (87.5%; 95% CI, 72.4-95.3%), followed by indirect culture (85.4%; 95% CI, 71.6-93.5%) and PCR (73.5%; 95% CI, 59.0-84.6%), with 100% specificity noted in all tests. Pairwise comparisons showed substantial agreement among the three tests (percent agreement = 81.8-86.2%, Cohen's k = 0.67-0.72). Clinico-microbiological correlation demonstrated higher culture-PCR concordance in cases with greater infection severity. Conclusions: This study highlights a similar diagnostic performance of direct culture, indirect culture and 16S rRNA PCR for bacterial keratitis, with substantial inter-test concordance. PCR serves as a useful diagnostic adjuvant to culture, particularly in culture-negative cases or those with lesser disease severity (where culture-PCR concordance is lower).

6.
Eye (Lond) ; 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39261654

RESUMO

BACKGROUND/OBJECTIVES: To examine the clinical characteristics, risk factors and outcomes of contact lens-related bacterial keratitis (CLBK) in a large UK tertiary referral centre. SUBJECTS/METHODS: A retrospective analysis of all patients who presented to the Queen's Medical Centre, Nottingham, UK, with suspected CLBK between October 2015 to September 2022 (a 7-year period) was performed. Relevant data on demographic factors, CL wear behaviour, causes, clinical characteristics, and outcomes were analysed. RESULTS: We included 138 patients with CLBK; the mean age was 42.0 ± 17.8 years and 74 (53.6%) patients were male. Most CLBK were related to soft CL wear (94.5%), particularly monthly disposable (42.5%) and daily disposable (24.4%) CLs. Poor CL wear behaviour/hygiene was documented in 57.1% cases. Among the 64 (46.4%) microbiological-positive cases (n = 73 organisms), Pseudomonas aeruginosa (36, 49.3%) and Staphylococcus spp. (16, 21.9%) were most commonly identified. Six (4.3%) cases were polymicrobial. Most (97.0%) patients were successfully treated with topical antibiotics alone, with 80.6% achieving good final corrected-distance-visual-acuity (CDVA) of ≥ 0.30 logMAR. Poor visual outcome (final CDVA < 0.30 logMAR) was significantly associated with presenting CDVA < 0.6 logMAR (p = 0.002) and central ulcer (p = 0.004). Poor corneal healing (complete healing of > 30 days from initial presentation) was significantly associated with age > 50 years (p = 0.028), female gender (p = 0.020), and infiltrate size >3 mm (p = 0.031). CONCLUSIONS: Poor CL wear behaviour/hygiene is commonly observed in CLBK, highlighting the importance of improved counselling and awareness regarding CL use and hygiene. When presented early and managed appropriately, most patients are able to achieve good clinical outcomes with medical treatment alone.

7.
Ophthalmology ; 120(9): 1778-85, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23714320

RESUMO

PURPOSE: To define and characterize a novel pre-Descemet's layer in the human cornea. DESIGN: Clinical and experimental study. PARTICIPANTS: We included 31 human donor sclerocorneal discs, including 6 controls (mean age, 77.7 years). METHODS: Air was injected into the stroma of donor whole globes (n = 4) and sclerocorneal discs (n = 21) as in the clinical deep anterior lamellar keratoplasty procedure with the big bubble (BB) technique. The following experiments were performed: (1) creation of BB followed by peeling of the Descemet's membrane (DM); (2) peeling off of the DM followed by creation of the BB, and (3) creation of the BB and continued inflation until the bubble popped to measure the popping pressure. Tissue obtained from these experiments was subjected to histologic examination. MAIN OUTCOME MEASURES: Demonstration of a novel pre-Descemet's layer (Dua's layer) in the human cornea. RESULTS: Three types of BB were obtained. Type-1, is a well-circumscribed, central dome-shaped elevation up to 8.5 mm in diameter (n = 14). Type-2, is a thin-walled, large BB of maximum 10.5 mm diameter, which always started at the periphery, enlarging centrally to form a large BB (n = 5), and a mixed type (n = 3). With type-1 BB, unlike type-2 BB, it was possible to peel off DM completely without deflating the BB, indicating the presence of an additional layer of tissue. A type-1 BB could be created after first peeling off the DM (n = 5), confirming that DM was not essential to create a type-1 BB. The popping pressure was 1.45 bar and 0.6 bar for type-1 BB and type-2 BB, respectively. Histology confirmed that the cleavage occurred beyond the last row of keratocytes. This layer was acellular, measured 10.15 ± 3.6 microns composed of 5 to 8 lamellae of predominantly type-1 collagen bundles arranged in transverse, longitudinal, and oblique directions. CONCLUSIONS: There exists a novel, well-defined, acellular, strong layer in the pre-Descemet's cornea. This separates along the last row of keratocytes in most cases performed with the BB technique. Its recognition will have considerable impact on posterior corneal surgery and the understanding of corneal biomechanics and posterior corneal pathology such as acute hydrops, Descematocele and pre-Descemet's dystrophies. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.


Assuntos
Membrana Basal/anatomia & histologia , Córnea/anatomia & histologia , Lâmina Limitante Posterior/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Membrana Basal/metabolismo , Membrana Basal/ultraestrutura , Colágeno Tipo I/metabolismo , Colágeno Tipo V/metabolismo , Córnea/ultraestrutura , Ceratócitos da Córnea/ultraestrutura , Lâmina Limitante Posterior/ultraestrutura , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Masculino , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade , Doadores de Tecidos , Coleta de Tecidos e Órgãos/métodos
8.
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
9.
Prog Retin Eye Res ; 97: 101161, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-36642673

RESUMO

The pre-Descemet's layer/Dua's layer, also termed the Dua-Fine layer and the pre-posterior limiting lamina layer, lies anterior to the Descemet's membrane in the cornea, is 10 µm (range 6-16) thick, made predominantly of type I and some type VI collagen with abundant elastin, more than any other layer of the cornea. It has high tensile strength (bursting pressure up to 700 mm of Hg), is impervious to air and almost acellular. At the periphery it demonstrates fenestrations and ramifies to become the core of the trabecular meshwork, with implications for intraocular pressure and glaucoma. It has been demonstrated in some species of animals. The layer has assumed considerable importance in anterior and posterior lamellar corneal transplant surgery by improving our understanding of the behaviour of corneal tissue during these procedures, improved techniques and made the surgery safer with better outcomes. It has led to the innovation of new surgical procedures namely, pre-Descemet's endothelial keratoplasty, suture management of acute hydrops, DALK-triple and Fogla's mini DALK. The discovery and knowledge of the layer has introduced paradigm shifts in our age old concepts of Descemet's membrane detachment, acute corneal hydrops in keratoconus and Descemetoceles, with impact on management approaches. It has been shown to contribute to the pathology and clinical signs observed in corneal infections and some corneal dystrophies. Early evidence suggests that it may have a role in the pathogenesis of keratoconus in relation to its elastin content. Its contribution to corneal biomechanics and glaucoma are subjects of current investigations.


Assuntos
Transplante de Córnea , Glaucoma , Ceratocone , Humanos , Lâmina Limitante Posterior/cirurgia , Ceratocone/diagnóstico , Elastina , Transplante de Córnea/métodos , Edema/cirurgia , Glaucoma/cirurgia
10.
Indian J Ophthalmol ; 71(9): 3178-3185, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37602605

RESUMO

Purpose: We aimed to determine whether Descemet's membrane (DM) scrolling occurs primarily along the vertical or horizontal axis and establish whether oval trephination along the axis of least scrolling can reduce the grade of the scroll. Methods: The longest limbus-to-limbus axis on 28 sclerocorneal discs was taken as the horizontal axis. The horizontal (n = 7) or (right angles to it) vertical (n = 6) axis was marked on DM before peeling it off. The direction and grade of scrolling was observed. Narrow strips (3-4 mm wide) were then cut along the two axes (n = 4 each) and the scrolling pattern was observed. Ellipses (7 × 9 mm) of DM were punched along the two axes (n = 6 each) and the scrolls graded. Immunofluorescent staining for elastin on horizontal and vertical tissue sections from three DM samples was performed. The intensity and thickness of elastin staining were measured. Results: Twenty-four (85.72%) DM samples showed scrolling along the horizontal axis, none showed scrolling along the vertical axis, and four (14.28%) samples showed a spiral scroll, regardless of which axis was marked (grade 3.7 and 3.6). Vertically oval discs showed significantly reduced scrolling (grade 1.2) compared to horizontally oval discs (grade 3.5). Narrow strips of DM showed a similar scrolling pattern. Immunohistology showed no difference in any of the parameters examined along the two axes or from the center to the periphery. Conclusion: DM scrolls primarily along the horizontal axis. Vertically oval DM samples show minimal scrolling, which can be an advantage in DMEK. Differential scrolling is not determined by the distribution of elastin.


Assuntos
Doenças da Córnea , Transplante de Córnea , Humanos , Lâmina Limitante Posterior/cirurgia , Elastina , Doenças da Córnea/diagnóstico , Doenças da Córnea/cirurgia , Coloração e Rotulagem
11.
Front Cell Infect Microbiol ; 13: 1250599, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37712055

RESUMO

Background/objectives: Post-keratoplasty infectious keratitis (PKIK) is a unique sight-threatening clinical entity which often poses significant therapeutic challenges. This study aimed to examine the clinical presentation, risk factors, management, and clinical outcomes of PKIK. Methods: This was a retrospective study of all patients who presented to the Queen's Medical Centre, Nottingham, with PKIK between September 2015 and August 2022 (a 7-year period). Relevant data on types of keratoplasty, clinical presentations, causative microorganisms, management, and outcome were analyzed. Results: Forty-nine PKIK cases, including four cases of interface infectious keratitis, were identified during the study period. The most common graft indications for PKP, DALK and EK were failed grafts (9, 37.5%), keratoconus (6, 54.5%) and Fuchs endothelial corneal dystrophy (FECD; 8, 57.1%), respectively. Staphylococcus spp. were the most commonly identified organisms (15, 50.0%). Bullous keratopathy (18, 36.7%), ocular surface disease (18, 36.7%), and broken/loose sutures (15, 30.6%) were the most common risk factors. Concurrent use of topical steroids was identified in 25 (51.0%) cases. Of 31 functioning grafts at presentation, 12 (38.7%) grafts failed at final follow-up with 15 (48.4%) patients retaining a CDVA of ≥1.0 logMAR. The overall estimated 5-year survival rate post-PKIK was 55.9% (95% CI, 35.9%-75.9%), with DALK having the highest survival rate [63.6% (95% CI, 28.9%-98.3%)], followed by EK [57.1% (95% CI, 20.4%-93.8%)] and PKP [52.7% (95% CI, 25.1%-80.3%)], though no statistical difference was observed (p=0.48). Conclusions: PKIK represents an important cause of IK and graft failure. Bullous keratopathy, OSD and suture-related complications are the commonest risk factors, highlighting the potential benefit of prophylactic topical antibiotics (for unhealthy ocular surface) and early suture removal (where possible) in reducing the risk of PKIK. Graft survival may be higher in lamellar keratoplasty following PKIK but larger studies are required to elucidate this observation.


Assuntos
Transplante de Córnea , Ceratite , Humanos , Estudos Retrospectivos , Ceratite/tratamento farmacológico , Ceratite/epidemiologia , Fatores de Risco , Olho , Transplante de Córnea/efeitos adversos
12.
Ocul Surf ; 28: 401-412, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-34592475

RESUMO

The successful management of infectious keratitis is usually achieved with a combination of tools for accurate diagnosis and targeted timely antimicrobial therapy. An armamentarium of surgical interventions is available in the acute stage which can be resorted to in a step wise manner or in combination guided by the response to treatment. Simple surgical modalities can facilitate accurate diagnosis e.g. corneal biopsy and alcohol delamination. Surgery to promote epithelial healing can vary from tarsorrhaphy, amniotic membrane transplantation or conjunctival flaps depending on the extent of infection, visual prognosis, availability of tissue and surgeon's experience. Collagen crosslinking has been increasingly utilized with successful results to strengthen the cornea and reduce the infective load consequently the need for further elaborate surgical interventions. It has shown encouraging results specially in superficial bacterial and fungal keratitis but for deeper infections, viral and acanthamoeba keratitis, its use remains questionable. When globe integrity is compromised, corneal gluing is the most commonly used procedure to seal small perforations. In larger perforations/fulminant infections a tectonic/therapeutic graft is advisable. Partial thickness grafts are increasingly popular to treat superficial infection or internally tamponade perforations. Peripheral therapeutic grafts face challenges with potential requirement for a manually fashioned graft, and increased risk of rejection due to proximity to the limbal vessels. Late stage visual rehabilitation is likely to require further surgical interventions after complete resolution of infection and inflammation. A preliminary assessment of corneal sensation and integrity of the ocular surface are key for any successful surgical intervention to restore vision.


Assuntos
Úlcera da Córnea , Ceratite , Humanos , Ceratite/cirurgia , Córnea , Bactérias , Túnica Conjuntiva
13.
Sci Rep ; 13(1): 5922, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-37041151

RESUMO

The recent discovery and characterization of pre-Descemet's layer (PDL; also termed the Dua's layer or the Dua-Fine layer) has advanced the understanding of various posterior corneal pathologies and surgeries in human. This study aimed to characterize the ultrastructure of the posterior stroma and interfacial zone of Descemet's membrane (DM) in canine eyes. Eighteen canine corneo-scleral discs were included. Intrastromal air injection resulted in the formation of type 1 big bubble (BB) in 73% (n = 11/15) of corneas, with a mean diameter of 11.0 ± 1.3 mm. No type 2 BB was created. Anterior segment optical coherence tomography, histology and transmission electron microscopy confirmed that the wall of BB was composed of DM, in contact with remaining stroma (canine PDL; cPDL). The cPDL was populated with keratocytes, of varying thickness of 16.2 ± 4.2 µm in close apposition to the DM, and composed of collagen bundles arranged in transverse, longitudinal and oblique directions. The interfacial zone, between DM and cPDL, showed fibril extension in all three directions, predominantly longitudinal. Irregular extensions of DM material into cPDL stroma were observed. No long-spaced collagen was detected. In conclusion, there exists a well-defined cleavage plane between the posterior stroma and cPDL, with similar but not identical characteristics as in humans, that is revealed by pneumodissection. This adds to our understanding of the anatomy of the posterior most canine cornea, which will have significant clinical impact on posterior corneal surgery and understanding of corneal pathology in dogs.


Assuntos
Transplante de Córnea , Lâmina Limitante Posterior , Cães , Animais , Humanos , Lâmina Limitante Posterior/cirurgia , Transplante de Córnea/métodos , Doadores de Tecidos , Córnea/ultraestrutura , Colágeno
14.
Front Med (Lausanne) ; 10: 1212314, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37409272

RESUMO

Keratoconus is the most common corneal ectatic disorder. It is characterized by progressive corneal thinning with resultant irregular astigmatism and myopia. Its prevalence has been estimated at 1:375 to 1:2,000 people globally, with a considerably higher rate in the younger populations. Over the past two decades, there was a paradigm shift in the management of keratoconus. The treatment has expanded significantly from conservative management (e.g., spectacles and contact lenses wear) and penetrating keratoplasty to many other therapeutic and refractive modalities, including corneal cross-linking (with various protocols/techniques), combined CXL-keratorefractive surgeries, intracorneal ring segments, anterior lamellar keratoplasty, and more recently, Bowman's layer transplantation, stromal keratophakia, and stromal regeneration. Several recent large genome-wide association studies (GWAS) have identified important genetic mutations relevant to keratoconus, facilitating the development of potential gene therapy targeting keratoconus and halting the disease progression. In addition, attempts have been made to leverage the power of artificial intelligence-assisted algorithms in enabling earlier detection and progression prediction in keratoconus. In this review, we provide a comprehensive overview of the current and emerging treatment of keratoconus and propose a treatment algorithm for systematically guiding the management of this common clinical entity.

15.
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
16.
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
17.
Ocul Immunol Inflamm ; 30(5): 1136-1141, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35412952

RESUMO

PURPOSE: To highlight the potential risk of herpetic eye disease (HED) reactivation following COVID-19 vaccine. METHODS: Retrospective analysis of all patients who presented with HED within 28 days post-first dose COVID-19 vaccination. RESULTS: Eleven eyes (n = 10 patients) were included. The mean interval between COVID-19 vaccination and ocular symptoms/signs was 12.3 ± 10.3 days. Four (40%) patients presented with HSV keratitis, and six (60%) patients presented with VZV keratitis (five had concurrent other signs of herpes zoster ophthalmicus). Common ocular signs included multiple scattered dendritic/pseudodendritic corneal epitheliopathy (90.9%), anterior uveitis (63.6%), and endothelitis (27.3%). All cases were successfully treated with topical and systemic antiviral treatment and/or topical corticosteroids (mean healing time = 3.9 ± 1.6 weeks). CONCLUSIONS: Our case series highlights the potential temporal association between HED and COVID-19 vaccine. Prophylactic antiviral treatment is recommended in patients with a history of HED prior to COVID-19 vaccination.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Herpes Zoster Oftálmico , Ceratite Herpética , Humanos , Antivirais/uso terapêutico , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , Glucocorticoides/uso terapêutico , Herpes Zoster Oftálmico/induzido quimicamente , Herpes Zoster Oftálmico/diagnóstico , Herpes Zoster Oftálmico/tratamento farmacológico , Ceratite Herpética/induzido quimicamente , Ceratite Herpética/diagnóstico , Ceratite Herpética/tratamento farmacológico , Estudos Retrospectivos , Reino Unido/epidemiologia
18.
Ocul Surf ; 23: 27-39, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34781020

RESUMO

Infectious keratitis (IK) represents the leading cause of corneal blindness worldwide, particularly in developing countries. A good outcome of IK is contingent upon timely and accurate diagnosis followed by appropriate interventions. Currently, IK is primarily diagnosed on clinical grounds supplemented by microbiological investigations such as microscopic examination with stains, and culture and sensitivity testing. Although this is the most widely accepted practice adopted in most regions, such an approach is challenged by several factors, including indistinguishable clinical features shared among different causative organisms, polymicrobial infection, long diagnostic turnaround time, and variably low culture positivity rate. In this review, we aim to provide a comprehensive overview of the current diagnostic armamentarium of IK, encompassing conventional microbiological investigations, molecular diagnostics (including polymerase chain reaction and mass spectrometry), and imaging modalities (including anterior segment optical coherence tomography and in vivo confocal microscopy). We also highlight the potential roles of emerging technologies such as next-generation sequencing, artificial intelligence-assisted platforms. and tele-medicine in shaping the future diagnostic landscape of IK.


Assuntos
Inteligência Artificial , Ceratite , Córnea , Humanos , Ceratite/diagnóstico , Ceratite/microbiologia , Tomografia de Coerência Óptica
19.
Ophthalmology ; 118(7): 1265-71, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21458075

RESUMO

OBJECTIVE: To study the long-term changes at donor sites and safety implications for donor eyes used for harvesting tissue for autologous and living-related donor limbal transplants. DESIGN: Retrospective, observational, consecutive case series. PARTICIPANTS: We examined 50 donor sites of limbal tissue belonging to 25 healthy eyes (23 human subjects). METHODS: The corneas and limbus of donor eyes were assessed for symptoms and visual acuity and examined by slit-lamp biomicroscopy and in vivo confocal microscopy with particular emphasis on the donor sites and central cornea. MAIN OUTCOME MEASURES: In the donor eyes, we assessed visual acuity, persistence of symptoms, stability of the corneal epithelium, and the clinical and microscopic changes that occurred at the donor sites. RESULTS: Mean follow-up was 41±38 months (median, 24; range, 3-127). All eyes had symptoms of ocular discomfort up to 4 weeks postoperatively and remained asymptomatic thereafter. No patient reported subjective reduction in visual acuity. Mean best-corrected visual acuity (logarithm of the minimum angle of resolution fraction) preoperatively was 0.076±0.19 and postoperatively was 0.09±0.17 (P = 0.57). All donor sites showed re-epithelialization of the peripheral denuded limbus within 2 weeks. Observed complications were filamentary keratitis and subconjunctival hemorrhage in 4 eyes. In vivo confocal microscopy confirmed that the central corneal epithelium remained normal in all eyes. The re-epithelialized donor site was covered with conjunctival epithelium in 17 sites of 10 eyes and with corneal epithelium in 7 sites of 5 eyes. CONCLUSIONS: Limbal donation of 2 clock-hours of the superior and inferior limbus with 3×3 mm of adjacent conjunctiva was a safe procedure in this group of patients, demonstrating stable vision and an intact corneal epithelium during the follow up period. Donor sites can be re-epithelized by multiple layers of either corneal or conjunctival epithelium and is associated with deep stromal scarring.


Assuntos
Transplante de Córnea , Limbo da Córnea , Doadores Vivos , Coleta de Tecidos e Órgãos/efeitos adversos , Adulto , Idoso , Cicatriz/etiologia , Túnica Conjuntiva/irrigação sanguínea , Substância Própria/patologia , Epitélio Corneano/patologia , Óculos , Feminino , Seguimentos , Hemorragia/etiologia , Humanos , Ceratite/etiologia , Masculino , Microscopia Confocal , Pessoa de Meia-Idade , Dor/etiologia , Estudos Retrospectivos , Fatores de Tempo , Transplante Autólogo , Acuidade Visual , Adulto Jovem
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