Metaboloma use in ophthalmology / Uso de metaboloma em oftalmologia: uma revisão narrativa

ABSTRACT It is part of the omic sciences to search for an understanding of how the cellular system of organisms works as well as studying their biological changes. As part of the omic sciences, we can highlight the genomics whose function is the study of genes, the transcriptomics that studies the changes in the transcripts, the proteomics responsible for understanding the changes that occur in proteins, and the metabolomics that studies all the metabolic changes that occur in a certain system when it is submitted to different types of stimuli. Metabolomics is the science that studies the endogenous and exogenous metabolites in biological systems, which aims to provide comparative quantitative or semi-quantitative information about all metabolites in the system. This review aims to describe the main applications of metabolomics science in ophthalmolog. We searched the literature on main applications of metabolomics science in ophthalmology, using the MEDLINE and LILACS databases, with the keywords "metabolomics" and "ophthalmology", from January 1, 2009, to April 5, 2021. We retrieved 216 references, of which 58 were considered eligible for intensive review and critical analysis. The study of the metabolome allows a better understanding of the metabolism of ocular tissues. The results are important to aid diagnosis and as predictors of the progression of many eye and systemic diseases.

RESUMO Faz parte das ciências ômicas buscar entender como funciona o sistema celular dos organismos e estudar suas alterações biológicas. Como parte das ciências ômicas, destacam-se a genômica, cuja função é o estudo dos genes; a transcriptômica, que estuda as mudanças nos transcritos; a proteômica, responsável por entender as mudanças que ocorrem nas proteínas, e a metabolômica, que estuda todo o metabolismo das alterações que ocorrem em um determinado sistema quando ele é submetido a diferentes tipos de estímulos. A metabolômica é a ciência que estuda os metabólitos endógenos e exógenos em sistemas biológicos, visando fornecer informações comparativas quantitativas ou semiquantitativas sobre todos os metabólitos do sistema. Esta revisão teve como objetivo descrever as principais aplicações da ciência metabolômica na oftalmologia. Trata-se de revisão narrativa desenvolvida por um grupo de pesquisa da Universidade Federal de São Paulo, em São Paulo (SP). Buscaram-se, na literatura, as principais aplicações da ciência metabolômica em oftalmologia, utilizando as bases de dados Medline® e Lilacs, com as palavras-chave "metabolomics" e "oftalmologia", de 1º de janeiro de 2009 a 5 de abril de 2021. Foram recuperadas 216 referências, das quais 58 foram consideradas elegíveis para revisão intensiva e análise crítica. O estudo do metaboloma permite um melhor entendimento do metabolismo dos tecidos oculares. Os resultados são importantes para auxiliar no diagnóstico e como preditores da progressão de muitas doenças oculares e sistêmicas.

Use of gabapentin in management of postoperative pain after crosslinking / Uso da gabapentina no manejo da dor pós-operatória do crosslinking

ABSTRACT Objective: The objective was to evaluate the efficacy of gabapentin in the management of neuropathic pain in patients with keratoconus, who were treated with fast (10 minutes) epi-off corneal crosslinking (CXL). Methods: This was a prospective, double-blind, randomized study. The sample comprised patients with bilateral progressive keratoconus, aged 12 years or older, who underwent a bilateral epi-off corneal CXL (fast - 10 minutes) procedure. One group was given placebo orally, and the other group received gabapentin 600 mg orally, both preoperatively. The visual analogue scale (VAS) was applied to record postoperative pain up to 48 hours after procedure. The study was conducted at the Belotto Stock Centro Oftalmológico, in the city of Joaçaba, Santa Catarina, Brazil, from June 2018 to September 2019. Results: At no point in the study significant differences were observed between groups, in terms of pain intensity measured by means of the VAS questionnaire, or of opioid use (Paco®), though opioid consumption was 21% lower in the group receiving gabapentin. Conclusion: We concluded gabapentin has no efficacy in postoperative pain control after epi-off corneal CXL (fast - 10 minutes). Although there was no statistically significant difference, the group that received gabapentin suffered less pain, resulting in lower opioid consumption. UTN number: U1111-1256-0330.

RESUMO Objetivo: Avaliar a eficácia do uso da gabapentina no manejo da dor neuropática em pacientes portadores de ceratocone submetidos ao tratamento de crosslinking corneano epi-off fast de 10 minutos. Métodos: Tratou-se de pesquisa prospectiva, duplo-cega, randomizada. A amostra foi composta de pacientes com ceratocone progressivo bilateral, a partir dos 12 anos de idade, submetidos ao procedimento de crosslinking corneano acelerado epi-off fast de 10 minutos bilateral. Um grupo recebeu placebo via oral e o outro, gabapentina 600mg, via oral, ambos no pré-operatório. A Escala Visual Analógica foi aplicada para registrar a dor pós-operatória até 48 horas após o procedimento. A pesquisa foi realizada no período de junho de 2018 a setembro de 2019 em um centro oftalmológico. Resultados: Não foram observadas diferenças estatísticas significativas para ambos os grupos, tanto na intensidade da dor medida pela Escala Visual Analógica, como na redução do uso do opioide (Paco®), em qualquer horário analisado durante um período de 48 horas. No entanto, houve redução de 21% no consumo de opioides pelo grupo que fez uso da gabapentina. Conclusão: A gabapentina não demonstrou eficácia no controle da dor no pós-operatório do crosslinking corneano epi-off fast de 10 minutos. No entanto, observou-se que, mesmo não havendo diferença estatisticamente significativa, houve diminuição da dor no grupo em que foi usada a gabapentina, resultando na redução do consumo de opioides. Número UTN: U1111-1256-0330.

Investigating the effect of intracameral cefuroxime on oxidative stress and apoptosis in the rat cornea / Investigando o efeito de cefuroxima intracameral sobre o estresse oxidativo e a apoptose na córnea de ratos

ABSTRACT PURPOSE: We examined the effect of intracameral administration of cefuroxime on oxidative stress and endothelial apoptosis in rat corneal tissue. METHODS: In total, 30 rats were divided into 3 groups of 10 rats each (intracameral administration of cefuroxime 0.1 mg/0.01 mL (cefuroxime group); intracameral administration of balanced salt solution 0.01 mL (control group); or absence of intracameral injection (sham group). Corneal endothelial apoptosis was assessed by immunohistochemical analysis using caspase-3 and caspase-8. Total oxidant status, total antioxidant status, oxidative stress index, and paraoxonase and arylesterase levels were examined in corneal endothelial tissue and serum. RESULTS: Paraoxonase levels in the serum were significantly different between the sham and cefuroxime groups (p=0.027). A significant difference was also observed in total oxidant status levels between the cefuroxime and balanced salt solution groups (p=0.023). In addition, there were significant differences in total antioxidant status levels in corneal tissue between the cefuroxime and sham groups (p<0.001) and between the cefuroxime and balanced salt solution groups (p<0.001). Furthermore, significant differences were also observed in oxidative stress index levels between the cefuroxime and balanced salt solution groups (p=0.001) and between the cefuroxime and sham groups (p=0.026). According to the immunohistochemical staining results, a significant association with caspase-3 activity existed between the cefuroxime and balanced salt solution groups (p=0.007), while no significant difference was found with caspase-8 activity (p=0.541). Caspase-3 activity exhibited a significant relationship between the sham and balanced salt solution groups (p=0.018), but no relationship was found with caspase-8 activity (p=0.623). CONCLUSION: Immunohistochemical examination revealed that intracameral cefuroxime increased apoptosis when compared to the sham and balanced salt solution groups. Moreover, intracameral cefuroxime increased oxidative stress in the cornea and simultaneously induced apoptosis.

RESUMO OBJETIVO: Examinamos o efeito da administração intracameral da cefuroxima sobre o estresse oxidativo e a apoptose endotelial no tecido corneano de ratos. MÉTODOS: No total, 30 ratos foram divididos em 3 grupos de 10 ratos cada (administração intracameral de cefuroxima 0,1 mg/0,01 mL (grupo cefuroxima), administração intracameral de solução salina balanceada 0,01 mL (grupo controle) ou ausência de injeção intracameral (grupo sham)). A apoptose endotelial da córnea foi avaliada por análise imuno-histoquimica usando caspase-3 e -8. O status oxidante total, o status antioxidante total, o índice de estresse oxidativo e os níveis de a paraoxonase e arilesterase foram investigados no tecido endotelial da córnea e no soro. RESULTADOS: Os níveis de paraoxonase no soro foram significativamente diferentes entre os grupos sham e cefuroxima (p=0,027). Foi também observada uma diferença significativa nos níveis de estado oxidante total entre os grupos cefuroxima e solução salina balanceada (p=0,023). Além disso, houve diferenças significativas nos níveis de status antioxidante total no tecido da córnea entre os grupos cefuroxima e sham (p<0,001) e entre os grupos cefuroxima e solução salina balanceada (p<0,001). Diferenças significativas também foram observadas nos níveis do índice de estresse oxidativo entre os grupos cefuroxima e solução salina balanceada (p=0,001) e entre os grupos cefuroxima e sham (p=0,026). De acordo com os resultados de coloração imuno-histoquimica, houve associação significativa com a atividade da caspase-3 entre os grupos cefuroxima e solução salina balanceada (p=0,007), enquanto não houve diferença significativa com a atividade da caspase-8 (p=0,541). A atividade da caspase-3 exibiu uma relação significativa entre os grupos sham e solução salina balanceada (p=0,018), mas nenhuma relação foi encontrada com a atividade da caspase-8 (p=0,623). CONCLUSÃO: O exame imuno-histoquímico revelou que a cefuroxima intracameral aumentou a apoptose quando comparada com os grupos sham e solução salina balanceada. Além disso, a cefuroxima intracameral aumentou o estresse oxidativo na córnea e induziu simultaneamente a apoptose.

Accelerated collagen cross-linking in the management of advanced Acanthamoeba keratitis / Cross-linking acelerado de colágeno no controle da ceratite por Acanthamoeba avançada

ABSTRACT Purpose: To report our initial experience in the treatment of Acanthamoeba keratitis with accelerated corneal collagen cross-linking. Methods: Retrospective chart review of patients diagnosed with Acanthamoeba keratitis with progressive corneal melting who were treated with accelerated collagen cross-linking. Results: A total of 6 eyes (5 patients) were reviewed. All the patients received adjuvant therapy with moxifloxacin and chlorhexidine. In 4 cases, the ulcer healed with a mean interval to epithelialization of 108.8 days (range 59-217). In 2 eyes, there was a persistent neurotrophic ulcer. The melting was not progressive in any case, nor did any eye required emergency penetrating keratoplasy. Conclusion: This study suggests a beneficial effect of accelerated collagen cross-linking in cases of Acanthamoeba keratitis with corneal melting. Thus, collagen cross-linking may be considered as adjuvant treatment for Acanthamoeba keratitis.

RESUMO Objetivo: Relatar nossa experiência inicial no tra tamento da ceratite por Acanthamoeba com reticulação acelerada de colágeno corneano. Métodos: Revisão retrospectiva de prontuários de pacientes diagnosticados com ceratite por Acanthamoeba, com deformação progressiva da córnea, tratados com reticulação acelerada de colágeno. Resultados: Seis olhos (5 pacientes) foram incluídos. Todos os pacientes receberam terapia adjuvante com moxifloxacina e clorexidina. Em 4 casos, a úlcera cicatrizou com uma média de epitelização de 108,8 dias (amplitude de 59-217 dias). Em dois pacientes, a úlcera apresentou um comportamento neurotrófico. A deformação não foi progressiva em nenhum dos pacientes e nenhum dos olhos exigiu ceratoplastia penetrante de emergência. Conclusão: Este estudo sugeriu um efeito benéfico da reticulação acelerada de colágeno em casos de ceratite por Acanthamoeba infecciosa com deformação corneal. A reticulação de colágeno parece ser uma alternativa coadjuvante possível para casos de ceratite por Acanthamoeba.

Cross-linking da cornea: protocolo padrão / Corneal Crosslinking: The Standard Protocol

RESUMO O objetivo desta revisão é de determinar as indicações e eficácia da cirurgia que promove novas ligações covalentes entre as fibras de colágeno da córnea, conhecida como Cross-Linking (CXL), assim como esclarecer seus objetivos. O ceratocone é uma doença ectasica da córnea, bilateral, assimétrica, que, principalmente, cursa com encurvamento e afinamentos progressivo, e se inicia em geral na segunda década de vida. O uso primário do CXL tem sido na interrupção da progressão do Ceratocone. Apesar do conhecido encurvamento no estroma da córnea ocorrer nesses pacientes, a fisiopatologia por trás do ceratocone ainda é desconhecida e parece ser multifatorial. Pela evidencia literária disponível até o momento, o CXL da córnea esta, portanto indicado nos pacientes com doença em progressão. Concluímos que existe evidencia suficiente para afirmar que o CXL da córnea é eficaz na estabilização da doença ectásica da cornea.

ABSTRACT The purpose of this review is to determine the indications and efficacy of the surgery that promotes new covalent bonds between the collagen fibers of the cornea, known as Cross-Linking (CXL), as well as to clarify its objectives. Keratoconus is a bilateral, asymmetric ectasic disease of the cornea that mainly courses with steepening and progressive thinning, and usually begins in the second decade of life. The primary use of CXL has been in discontinuing the progression of keratoconus. Although known corneal stromal remodeling occurs in these patients, the pathophysiology behind keratoconus is still unknown and appears to be multifactorial. By the literary evidence available to date, the CXL of the cornea is safely indicated in patients with progressing disease. We conclude that there is sufficient evidence to affirm that cornea CXL is effective in stabilizing corneal ectasic disease.

Lipid corneal degeneration after trabeculectomy with mitomicin 0. 02%

ABSTRACT One patient with a history of trabeculectomy with Mitomicin C 0.02%, but no history of systemic disorders, exhibited unilateral corneal lipid infiltrates, together with deep stromal vascularization. She was treated with a bevacizumab injection and penetrating keratoplasty. No sign of recurrence was noted after one year post-operative.

RESUMO Um paciente com história de trabeculectomia com Mitomicina C 0,02%, sem doenças sistêmicas pré-existentes, apresentou infiltrado lipídico corneano unilateral associado à vascularização intraestromal profunda. Injeção subconjuntival de Bevacizumabe foi realizada e posterior ceratoplastia penetrante. Não houve sinais de recorrência em um ano.

Efficacy of the Mineral Oil and Hyaluronic Acid Mixture Eye Drops in Murine Dry Eye

PURPOSE: To investigate the therapeutic effects of mineral oil (MO) and hyaluronic acid (HA) mixture eye drops on the tear film and ocular surface in a mouse model of experimental dry eye (EDE). METHODS: Eye drops consisting of 0.1% HA alone or mixed with 0.1%, 0.5%, or 5.0% MO were applied to desiccating stress-induced murine dry eyes. Tear volume, corneal irregularity score, tear film break-up time (TBUT), and corneal fluorescein staining scores were measured at 5 and 10 days after treatment. Ten days after treatment, goblet cells in the conjunctiva were counted after Periodic acid-Schiff staining. RESULTS: There was no significant difference in the tear volume between desiccating stress-induced groups. The corneal irregularity score was lower in the 0.5% MO group compared with the EDE and HA groups. The 0.5% and 5.0% MO groups showed a significant improvement in TBUT compared with the EDE group. Mice treated with 0.1% and 0.5% MO mixture eye drops showed a significant improvement in fluorescein staining scores compared with the EDE group and the HA group. The conjunctival goblet cell count was higher in the 0.5% MO group compared with the EDE group and HA group. CONCLUSIONS: The MO and HA mixture eye drops had a beneficial effect on the tear films and ocular surface of murine dry eye. The application of 0.5% MO and 0.1% HA mixture eye drops could improve corneal irregularity, the corneal fluorescein staining score, and conjunctival goblet cell count compared with 0.1% HA eye drops in the treatment of EDE.

Prognóstico visual de 'crosslinking' para ceratocone com base em tomografia de córnea pré-operatória / Visual prognosis of crosslinking for kearatoconus based on preoperative corneal tomography

Objetivo: Verificar índices tomográficos do pré-operatório de pacientes com ceratocone submetidos à crosslinking corneano (CXL) como fatores preditivos para a melhora na acuidade visual corrigidas (AVc) após um ano. Métodos: Estudo retrospectivo que incluiu 63 olhos de 53 pacientes com ceratocone progressivo submetidos à CXL segundo o protocolo de Dresden: deseptelização corneana, riboflavina 0,1% por 30 minutos e luz ultra-violeta A (UVA) a uma irradiância de 3mW/cm2 por 30 minutos. Foram avaliados exames de tomografia corneana com sistema de Scheimpflug rotacional (Pentacam, Oculus) antes do CXL e a acuidade visual corrigida antes e após a cirurgia. A análise estatística foi feita com o teste de Kolmorov-Smirnov, teste t de student e curvas de característica operador-receptor (ROC). Resultados: Houve diferença estatisticamente significante (p<0,05) entre os pacientes que obtiveram melhora de AVc em um ano e os que não experimentaram melhora na AVc nesse período nos índices tomográficos pré-operatórios relacionados com espessura e volume corneano. Entre os pacientes que obtiveram melhora na AVc todos possuíam volume corneano em 6,0mm maior que 14,55mm3 e 97,2% deles possuíam volume corneano em 6,5mm maior que 17,76mm3. Assim como, 94,29% desses pacientes apresentavam paquimetria média em 4,0mm maior que 487 μm e 82,86% paquimetria no ponto mais fino maior de 421 μm. Conclusão: Pacientes com ceratocone menos avançado (volume e espessura da córnea maiores) no período pré-operatório obtiveram mais chances de ter melhora da AVc um ano após CXL. Estudos prospectivos envolvendo outras variáveis relacionadas com a aberrometria total e o estudo biomecânico da córnea são relevantes para se aumentar a capacidade prognóstica do resultado após CXL. .

Purpose: To verify pre-operative tomographic indices as predictive parameters for the improvement in best corrected visual acuity (BCVA) in one year after corneal collagen crosslinking (CXL) procedure for keratoconus. Methods: Retrospective study that included 63 eyes of 53 patients with progressive keratoconus submitted to CXL following the Dresden’s protocol: topical anesthesia, 9.0 mm of epithelial abrasion, riboflavin 0.1% drops for 30 minutes and ultraviolet-light A (UVA) with an irradiance of 3mW/cm2 for 30 minutes. Corneal tomography taken by Scheimplug rotational system (Pentacam, Oculus) before CXL was evaluated along with pre and 1 year post-operative BCVA. Statistical analysis was accomplished with the Kolmogorov-Smirnov test, student’s t-test and Receiver Operating Characteristic (ROC) curve. Results: There were statistically significant differences (p<0.05) between patients who improved BCVA in one year after CXL and those who did not experienced improvement in BCVA in the same period of time in the pre-operative tomographic indices related to corneal volume and thickness. Among those who had its BCVA improved all of them had a corneal volume in 6.0mm grater then 14.55mm3 and 97.2% of them had corneal volume in 6.5mm grater then 17.76mm3. So with 94.29% of them hadthickness in 4.0mm grater then 487μm and 82.86% had thickness on the thinnest point grater then 421μm. Conclusion: Patients with less advanced keratoconus (grater corneal volume and thickness) in the pre-operative had more chances to improve its BCVA in one year after CXL. Prospective studies involving others variables related to total aberrometry and corneal biomechanics are relevant to increase the prognostic capability of CXL result. .

Cytokeratin expression in corneal dystrophies / Expressão de citoqueratinas em distrofias corneanas

PURPOSE: To identify an immunohistochemical pattern of epithelial markers in granular, lattice and Avellino corneal dystrophies. METHODS: Twenty-two corneal buttons, diagnosed as lattice (17), Avellino (4) and granular (1) underwent immunohistochemical studies of cytokeratins (CKs) on pa- raffin-embedded sections (group I). Monoclonal antibodies for pan-CK (AE1/AE3) and CKs 3/12, 5/6, 8, 18 and 19 were used. Twenty-two normal corneas were used as the control (group II). RESULTS: Six lattice and 2 Avellino cases of group I stained positively with anti-CK 3/12 in corneal epithelium and areas of corneal stroma deposits. One of these cases of lattice was positive for anti-pan-CK (AE1/AE3) also in the epithelium and areas of corneal stroma deposits with a similar pattern. None of the controls (group II) revealed any staining in corneal stroma. All disease and control cases (groups I and II) revealed positive staining in corneal epithelium. CONCLUSION: AE1/AE3 and CK 3/12 anti-CK positive markers in the stromal deposits of lattice and Avellino dystrophies may suggest an epithelial genesis of the disease.

OBJETIVO: Investigar a expressão de citoqueratinas (CKs) em córneas com distrofias corneanas tipo granular, lattice e Avellino. MÉTODOS: Vinte e dois botões corneanos com diagnóstico anatomopatológico de distrofia estromal tipo lattice (17), Avellino (4) e granular (1) foram submetidos à avaliação imunohistoquímica nos tecidos inclusos em parafina (grupo I). Anticorpos monoclonais para pan-CK (AE1/AE3) e CKs de números 3/12, 5/6, 8, 18 e 19 foram utilizados. Vinte e dois botões corneanos normais foram usados como controle (grupo II). RESULTADOS: Oito casos do grupo I (seis lattice e dois Avellino) apresentaram reações imuno-histoquímicas positivas com anti-CK 3/12, tanto no epitélio como nos depósitos estromais e um destes casos (lattice) também se mostrou positivo para anti-pan-CK (AE1/AE3) com o mesmo padrão de reação. Nenhum caso do grupo II mostrou reação imuno-histoquímica positiva no estroma corneano. Na avaliação imuno-histoquímica dos grupos I e II, o epitélio apresentou uma reação positiva com o anticorpo anti-pan-CK (AE1/AE3) e com o anti-CK 3/12. CONCLUSÃO: O fato da pan-CK e CK 3/12 apresentarem uma reação positiva nos depósitos das distrofias tipo lattice e Avellino sugere uma origem epitelial desses depósitos corneanos.

Pigment Deposition of Cosmetic Contact Lenses on the Cornea after Intense Pulsed-Light Treatment

We report a case of corneal deposition of pigments from cosmetic contact lenses after intense pulsed-light (IPL) therapy. A 30-year-old female visited our outpatient clinic with ocular pain and epiphora in both eyes; these symptoms developed soon after she had undergone facial IPL treatment. She was wearing cosmetic contact lenses throughout the IPL procedure. At presentation, her uncorrected visual acuity was 2/20 in both eyes, and the slit-lamp examination revealed deposition of the color pigment of the cosmetic contact lens onto the corneal epithelium. We scraped the corneal epithelium along with the deposited pigments using a no. 15 blade; seven days after the procedure, the corneal epithelium had healed without any complications. This case highlights the importance of considering the possibility of ocular complications during IPL treatment, particularly in individuals using contact lenses. To prevent ocular damage, IPL procedures should be performed only after removing the lenses and applying eyeshields.

Factors Influencing the Prevalence of Amblyopia in Children with Anisometropia

PURPOSE: To evaluate factors that can influence the prevalence of amblyopia in children with anisometropia. METHODS: We retrospectively reviewed the records of 63 children 2 to 13 years of age who had anisometropic amblyopia with a difference in the refractive errors between the eyes of at least two diopters (D). The type of anisometropia (myopia, hyperopia, and astigmatism), degree of anisometropia (4 D), best corrected visual acuity (BCVA) of the amblyopic eye at the time of initial examination, BCVA differences between sound and amblyopic eyes, whether or not occlusion therapy was performed, compliance with occlusion therapy, and the patient's age when eyeglasses were first worn were investigated. RESULTS: There was an increase in the risk of amblyopia with increased magnitude of anisometropia (p=0.021). The prevalence of amblyopia was higher in the BCVA 4 lines between sound and amblyopic eyes (p=0.008 and p=0.045, respectively). There was no statistical relationship between the prevalence of amblyopia and the type of anisometropia or the age when eyeglasses were first worn. Poor compliance with occlusion therapy was less likely to achieve successful outcome (p=0.015). CONCLUSIONS: Eyes with poor initial visual acuities of 4 line difference in the BCVA between sound and amblyopic eyes at the initial visit may require active treatment.

The Effect of Bevacizumab on Corneal Neovascularization in Rabbits

PURPOSE: To determine the efficacy of topical application and subconjunctival injection of bevacizumab in the treatment of corneal neovascularization. METHODS: Corneal neovascularization was induced with a silk suture of the corneal stroma in 12 rabbits (24 eyes). One week after suturing, four rabbits were treated with topical bevacizumab at 5 mg/mL (group A) and another four rabbits were treated with topical bevacizumab 10 mg/mL (group B) in the right eyes twice a day for two weeks. A subconjunctival injection of bevacizumab 1.25 mg/mL was done in the right eyes of four rabbits (group C). All of the left eyes (12 eyes) were used as controls. The area of corneal neovascularization was measured after one and two weeks, and the concentration of vascular endothelial growth factor (VEGF) in corneal tissue was measured after two weeks. RESULTS: The neovascularized area was smaller in all treated groups than in the control group (p<0.001). Upon analysis of the neovascularized area, there was no significant difference between groups A and B. However, the mean neovascularized area of group B was significantly smaller than that of group C after two weeks of treatment (p=0.043). The histologic examination revealed fewer new corneal vessels in all treated groups than the control group. The concentration of VEGF was significantly lower in all treated groups compared to the control group (p<0.01), but no difference was shown between treated groups. CONCLUSIONS: Topical and subconjunctival bevacizumab application may be useful in the treatment of corneal neovascularization and further study is necessary.

Identification and Localization of Alpha-Synuclein in Human Cornea

No abstract available.

Avaliação da cinética do epitélio corneano com marcadores de proliferação celular / Evaluation of the corneal epithelium kinetics using cell proliferation markers

OBJETIVO: Avaliar a cinética celular do epitélio corneano de coelhas em três situações: controle, hiperproliferação e hipoproliferação celular, com a utilização dos marcadores de proliferação celular BrdU, Ki-67/MIB-1 e AgNOR. MÉTODOS: Foram utilizadas quinze coelhas albinas que tiveram seus olhos aleatoriamente divididos em 3 grupos (A, B e C). O grupo A incluiu olhos que foram submetidos à instilação de tampão fosfato (total de 10 olhos); o grupo B, instilação de tampão fosfato após a remoção de uma área central do epitélio corneano de 10 mm (total de 10 olhos) e o grupo C, instilação de 5-fluoruracil em superfície ocular íntegra (total de 10 olhos). RESULTADOS: Os resultados da média e desvio-padrão do número de células marcadas pela BrdU nos grupos A, B e C foram, respectivamente, de 7,17 ± 0,74; 35,00 ± 3,01 e 0,22 ± 0,1 células marcadas por 100 células basais. As diferenças entre os grupos foram estatisticamente significantes. A média e o desvio padrão do número de células marcadas utilizando o Ki-67 foram de 7,55 ± 1,22 no grupo A; 35,55 ± 3,84 no grupo B e 0,34 ± 0,14 no grupo C. As diferenças entre os grupos foram estatisticamente significantes. A média e o desvio-padrão da medida da área das NORs no grupo A foram de 1,92 ± 0,24, no grupo B foram de 3,61 ± 0,27 e no grupo C foram de 1,71 ± 0,26. CONCLUSÕES: Os marcadores BrdU, Ki-67 e AgNOR apresentaram uma correlação positiva e estatisticamente significante nas situações de proliferação celular avaliadas (controle, hiperproliferação e hipoproliferação); o emprego do AgNOR não permitiu identificar diferenças na proliferação celular nas situações controle e hipoproliferação e houve maior concordância de resultados entre a BrdU e o Ki-67 nas três situações de proliferação celular.

PURPOSE: In order to maintain its clear and uniform structure, the corneal epithelium needs constant equilibrium between production (division) and desquamation of its epithelial cells. The author aimed to evaluate the cell kinetics of corneal epithelium of rabbits in three situations (control, hypoproliferation and hyperproliferation) using BrdU, Ki-67/MIB-1 and AgNORs proliferation markers. METHODS: Fifteen white female rabbits had their eyes randomly divided into three groups (A, B and. C). Group A included eyes submitted to phosphate buffer saline instillation (total 10 eyes); group B, instillation of phosphate buffer saline after removing a 10 mm central area of the corneal epithelium (total 10 eyes) and group C, instillation of 5-fluorouracil in normal epithelium (total 10 eyes). RESULTS: The results of the mean number and standard deviation of the marked cells using BrdU in groups A, B e C were, respectively, 7.17 ± 0.74; 35.00 ± 3.01 e 0.22 ± 0.1 marked cells per 100 basal cells. Differences among groups were statistically significant. The mean number and standard deviation of the labelled cells using Ki-67 were 7.55 ± 1.22 in group A; 35.55 ± 3.84 in group B and 0.34 ± 0.14 in group C. Differences among groups were statistically significant. The mean area and standard deviation of NORs in group A were 1.92 ± 0.24, in group B, 3.61 ± 0.27 and in group C, 1.71 ± 0.26. CONCLUSIONS: The markers BrdU, Ki-67 and AgNOR showed a positive correlation with statistical significance among the cellular proliferation situations studied (control, hypoproliferation and hyperproliferation); the AgNOR did not show statistically significant differences among the control and hypoproliferation situations and there was more agreement in the results among markers BrdU and Ki-67 in three cell proliferation situations.

Corneal hydration intra-operatively during phacoemulsification.

PURPOSE: To evaluate incidence and risk factors for corneal hydration intra-operatively during phacoemulsification (CHIP). METHODS AND MATERIALS: This was a randomised, clinical trial, where 240 eyes of 240 patients with senile cataracts undergoing phacoemulsification were prospectively randomised to receive one of three possible types of incision architecture - single, two or three planes. Viscoelastic injection through paracentesis, before instruments were withdrawn from the main incision, was randomly done. Incision length was grouped into 1.5, 2 and 2.5 mm. CHIP was graded as nil, mild, moderate or severe: nil - no visible CHIP, mild-CHIP involving pillars of the incision, moderate - CHIP involving pillars and lateral extension, severe - extension of CHIP in front into the clear cornea. Moderate and severe categories were combined as 'significant' CHIP. Statistical analysis was done by logistic regression. RESULTS: The incidence of significant CHIP was 17.9 % (43 eyes out of 240). Five out of 80 eyes (6.25%) single plane, 8 out of 80 (10%) two plane and 30 out of 80 (37.5%) three- plane incisions developed significant CHIP (p = 0.005). Fifteen out of 120 (12.5%) with and 28 out of 120 (23.3%) without injection of viscoelastic developed significant CHIP (p = 0.044). Eighteen out of 43 (42.8%) and 25 out of 43(58.1%) with incision lengths 2 and 2.5 mm developed significant CHIP respectively (p<0.001). CONCLUSIONS: The incidence of significant CHIP was 17.9 %. Three-plane incisions, not injecting viscoelastic prior to retraction of instruments and incision length 2 mm or more are risk factors for significant CHIP.

Effects of Smoking on Tear Film and Ocular Surface

This study was performed to evaluate the changes of tear film and ocular surface caused by smoking. Symptom scoring, tear film break-up time (BUT), basal tear secretion test, corneal sensitivity test, keratoepitheliopathy scoring, and conjunctival impression cytology were performed in 29 smokers (58 eyes) and 26 non-smokers (52 eyes). Tear film BUT, basal tear secretion, corneal sensitivity, and squamous metaplasia were 7.71 +/- 2.66 sec, 6.29 +/- 2.85 mm, 53.69 +/- 5.69 mm, and 2.45 +/- 1.26 in smokers and 9.62 +/- 3.14 sec, 10.04 +/- 3.87 mm, 56.46 +/- 4.79 mm, and 1.12 +/- 0.83 in non-smokers, respectively (p< 0.05). Symptom score, keratoepitheliopathy score, and goblet cell density were not significantly different between the two groups. Tear film BUT was shorter, basal tear secretion and corneal sensitivity were lower, and squamous metaplasia was higher in heavy smokers than in light smokers. In conclusion, smoking deteriorates the tear film and ocular surface with decreased quantity and quality of tear film, decreased corneal sensitivity, and squamous metaplasia, and this deterioration is related to the amount of smoking.

Effect of preservative, antioxidant and viscolizing agents on in vitro transcorneal permeation of ketorolac tromethamine.

The influence of formulation additives, e.g. preservative, antioxidant and viscolizing agents on in vitro transcorneal permeation of ketorolac tromethamine from 0.5%(w/v) aqueous drop was studied using goat cornea. Permeation characteristics of drug, from selected formulations, through excised rabbit cornea were also evaluated. Aqueous solution of ketorolac tromethamine (0.5% w/v), pH 6.5 or 7.0 having ionic strength 0.2, was prepared. To this solution perservatives either alone or in combination with other additives were added to have drops of various composition. Permeation studies with goat cornea showed maximum permeation of ketorolac tromethamine from formulation containing benzalkonium chloride and disodium edetate. Increase in viscosity of drop resulted in decreased permeation of drug. Formulation containing benzalkonium chloride and disodium edetate also increased permeation of drug through rabbit cornea. Cumulative permeation of drug through rabbit cornea was found to be 2.3-2.4 fold higher than that observed with goat cornea.

Effect of epithelial debridement on human cornea proteoglycans

Corneal transparency is attributed to the regular spacing and diameter of collagen fibrils, and proteoglycans may play a role in fibrillogenesis and matrix assembly. Corneal scar tissue is opaque and this opacity is explained by decreased ultrastructural order that may be related to proteoglycan composition. Thus, the objectives of the present study were to characterize the proteoglycans synthesized by human corneal explants and to investigate the effect of mechanical epithelial debridement. Human corneas unsuitable for transplants were immersed in F-12 culture medium and maintained under tissue culture conditions. The proteoglycans synthesized in 24 h were labeled metabolically by the addition of 35S-sulfate to the medium. These compounds were extracted by 4 M GuHCl and identified by a combination of agarose gel electrophoresis, enzymatic degradation with protease and mucopolysaccharidases, and immunoblotting. Decorin was identified as the main dermatan sulfate proteoglycan and keratan sulfate proteoglycans were also prominent components. When the glycosaminoglycan side chains were analyzed, only keratan sulfate and dermatan sulfate were detected (~50 percent each). Nevertheless, when these compounds were 35S-labeled metabolically, the label in dermatan sulfate was greater than in keratan sulfate, suggesting a lower synthesis rate for keratan sulfate. 35S-Heparan sulfate also appeared. The removal of the epithelial layer caused a decrease in heparan sulfate labeling and induced the synthesis of dermatan sulfate by the stroma. The increased deposit of dermatan sulfate proteoglycans in the stroma suggests a functional relationship between epithelium and stroma that could be related to the corneal opacity that may appear after epithelial cell debridement

The role of nitric oxide in ocular surface diseases

The role of nitric oxide (NO) in ocular surface diseases remains unknown. We investigated the conditions leading to increase NO generation in tears and the main sources of ocular surface tissue. We evaluated the possibility of a dual action (cell survival or cell death) depending on the amount of NO. The concentration of nitrite plus nitrate, the stable end-product of NO, was measured in the tears of various ocular surface diseases. We also examined the main source of nitric oxide synthase (NOS) using immunohistochemical staining & Western blot analysis. When cultured human corneal fibroblasts were treated with NO producing donor with or without serum, the viability of cells was studied. We found that sources of NO in ocular surface tissue primarily included corneal epithelium, fibroblasts, endothelium and inflammatory cells. Three forms of NOS (eNOS, bNOS, & iNOS) were expressed in experimentally induced inflammation. Cell death by NO revealed TUNEL positive staining, however in the EM finding, this NO specific cell death was an atypical necrosis showing perinuclear large vacuolization and mitochondrial swelling. In the fibroblasts culture system, the NO donor (SNAP, S-nitroso-N-acetyl-D, L-penicillamine) prevented the death of corneal fibroblasts caused by serum deprivation in a dose dependent manner up to 500 m SNAP, although a higher dose decreased cell viability. This study suggested that NO might act as a double-edged sword in ocular surface disease depending on the degree of inflammatory condition related with NO concentration.

Effect of cryopreservation on lipid peroxidation in chick cornea.

A mechanism suggested to cause injury to the preserved organs in vitro is the generation of oxygen free radicals either during preservation or after transplantation due to reperfusion. Methods to suppress generation of oxygen free radicals may lead to improved methods of organ preservation. In this study, increase in the levels of lipid peroxidation in chick cornea after cryopreservation is reported. Addition of fetal bovine serum (FBS) in cryopreservation medium was found to prevent lipid peroxidation. Addition of FBS was also found to be protective towards corneal viability during cryopreservation.