Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
Arq. bras. oftalmol ; 84(3): 275-278, May-June 2021. graf
Artigo em Inglês | LILACS | ID: biblio-1248969

RESUMO

ABSTRACT Pseudoexfoliation syndrome is more frequent in people aged >50 yeears, and its prevalence increases with age. Few reports have described cases in younger patients, all with a history of ocular surgery, especially iris resection. Herein, we describe the case of a 27-year old man with bilateral advanced glaucoma and pseudoexfoliation material in OS. He had undergone cataract surgeries OU and a penetrating keratoplasty OD during childhood. Currently, he presented with an intraocular pressure of 40 mmHg OU. The OS showed a white flaky material in the pupillary rim and anterior capsule and a Sampaolesi line as a gonioscopic finding. Trabeculectomy was performed OU, and intraocular pressure control was achieved. Unlike other previously reported cases, this patient did not present any apparent iris manipulation in the affected eye. However, he did undergo an iridectomy in the contralateral eye. This is also the first case to be accompanied by bilateral glaucoma at the time of detection of the pseudoexfoliation material.(AU)


RESUMO A síndrome de pseudoesfoliação é mais frequente em pessoas com mais de 50 anos e sua prevalência aumenta com a idade. Poucos relatos descrevem casos em pacientes mais jovens, todos com história de cirurgia ocular, especialmente ressecção da íris. Descrevemos o caso de um homem de 27 anos com glaucoma bilateral avançado e material de pseudoesfoliação no OE. O paciente foi submetido a cirurgias de catarata em AO e a uma ceratoplastia penetrante no OD durante a infância. Atualmente, ele apresentou PIOs de 40 mmHg em AO. O OE apresentou material escamoso branco na borda pupilar e cápsula anterior, e linha Sampaolesi como achado gonioscópico. A trabeculectomia foi realizada em AO e obteve-se o controle da pressão intraocular. Diferentemente de outros casos relatados, o paciente não apresentou qualquer manipulação aparente da íris no olho afetado. No entanto, ele foi submetido a uma iridectomia no olho contralateral. Além disso, este é o primeiro caso a ser acompanhado de glaucoma bilateral no momento da detecção do material de pseudoesfoliação.(AU)


Assuntos
Humanos , Adulto , Extração de Catarata , Glaucoma/complicações , Síndrome de Exfoliação/fisiopatologia , Iridectomia/instrumentação
2.
Heliyon ; 7(3): e06421, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33763607

RESUMO

PURPOSE: Open-angle glaucoma (OAG) is a collective term for various subgroups of glaucoma of which primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PEG) are the most common. There is increasing evidence that both conditions have systemic ramifications. We wanted to examine to what extent lifespan and cause of death are influenced by POAG, pseudoexfoliation syndrome (PES), and PEG. MATERIALS AND METHODS: Of 1864 people who underwent an eye examination in 1985-86, the presence of PES and/or glaucoma, along with date and cause of death were recorded. Based on information from the National Death Registry, the individuals were classified into the following groups of systemic diseases regarded as causing death: Cardiovascular disease (with two subgroups), cerebrovascular disease and neoplasms. RESULTS: All 1864 persons were followed to death, up to 30 years after examination. No difference in lifespan was observed when comparing OAG (i.e. POAG and PEG together) with the rest of the population. When adjusting for gender and age at inclusion, patients with POAG showed a reduced lifespan in the cardiovascular death group (2.44 years, p = 0.043). When comparing lifespan in the neoplastic group in the glaucoma patients, POAG and PEG, directly against each other, a mean age difference of 6.87 years (p = 0.017) was found. CONCLUSIONS: POAG patients showed reduced lifespan due to neoplasia and cardiovascular disease. Persons with PES and PEG did not show these lifespan reductions. Our main conclusion is that POAG and PEG, the two main OAG subgroups, are very different disease entities both from an ocular and a systemic point of view.

3.
Arq Bras Oftalmol ; 84(3): 275-278, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33567030

RESUMO

Pseudoexfoliation syndrome is more frequent in people aged >50 yeears, and its prevalence increases with age. Few reports have described cases in younger patients, all with a history of ocular surgery, especially iris resection. Herein, we describe the case of a 27-year old man with bilateral advanced glaucoma and pseudoexfoliation material in OS. He had undergone cataract surgeries OU and a penetrating keratoplasty OD during childhood. Currently, he presented with an intraocular pressure of 40 mmHg OU. The OS showed a white flaky material in the pupillary rim and anterior capsule and a Sampaolesi line as a gonioscopic finding. Trabeculectomy was performed OU, and intraocular pressure control was achieved. Unlike other previously reported cases, this patient did not present any apparent iris manipulation in the affected eye. However, he did undergo an iridectomy in the contralateral eye. This is also the first case to be accompanied by bilateral glaucoma at the time of detection of the pseudoexfoliation material.


Assuntos
Síndrome de Exfoliação , Glaucoma , Trabeculectomia , Adulto , Glaucoma/cirurgia , Humanos , Pressão Intraocular , Masculino , Tonometria Ocular
4.
Sci Rep ; 11(1): 273, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431985

RESUMO

The eye lens is a unique organ as no cells can be replaced throughout life. This makes it decisive that the lens is protected against damaging UV-radiation. An ultraviolet (UV)-absorbing compound of unknown identity is present in the aqueous humor of geese (wild and domestic) and other birds flying at high altitudes. A goose aqueous humor extract, that was believed to contain the UV protective compound which was designated as "compound X", was fractionated and examined using a variety of spectroscopic techniques including LC-MS and high field one- and two dimensional-NMR methods. A series of compounds were identified but none of them appeared to be the UV protective "compound X". It may be that the level of the UV protective compound in goose aqueous humor is much less than the compounds identified in our investigation, or it may have been degraded by the isolation and chromatographic purification protocols used in our investigations.


Assuntos
Aves , Olho/efeitos da radiação , Raios Ultravioleta/efeitos adversos , Animais , Humor Aquoso/metabolismo , Ácido Ascórbico/metabolismo , Aves/metabolismo , Olho/metabolismo , Voo Animal
5.
PLoS One ; 15(12): e0242786, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33301476

RESUMO

PURPOSE: To describe prevalence, life-time prevalence and incidence of glaucoma in Norway over a 15-year period. MATERIALS AND METHODS: Data from The Norwegian Prescription Database was used to identify all prescriptions for glaucoma medication during the period 2004 to 2018. Population figures and lifespan data were obtained from The National Bureau of Statistics. RESULTS: Of a population of 5.3 million, a total of 75733 patients using glaucoma eye drops were identified in 2018. The national prevalence was thus 1.4%, whilst in those over 70 years of age, 8.0%. When divided into counties, the prevalence varied between 1.1 and 1.9%. Overall, the prevalence was stable in the period 2004-2018. Life time prevalence was found to be 9.4% for men and 10.2% for women. National one-year incidence proportion per 10000 was 17.0 for the total population and a peak incidence of 93.8/10000 in the 80-89 year age group was identified. CONCLUSIONS: Glaucoma prevalence remained stable during the period 2004-2018, while incidence decreased slightly in the elderly population.


Assuntos
Glaucoma/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Noruega/epidemiologia , Prevalência , Adulto Jovem
6.
Heliyon ; 4(10): e00832, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30302411

RESUMO

BACKGROUND: Pseudoexfoliation syndrome (PES) is a common eye condition, indicating a risk of various eye diseases. Whether or not PES has extra-ocular physiological or even pathophysiological implications has been a matter of controversy for years. METHODS: In total 1888 persons were examined for PES in 1985-86. Of these, 1864 (98·7%) had died and were therefore available for analysis by 01.01.2016. Age and cause(s) of death were recorded. 9 diagnostic groups (cardiovascular disease, cerebrovascular disease, neoplasms, systemic hypertension, diabetes mellitus (DM), chronic obstructive pulmonary disease (COPD), Parkinson's disease, aortic aneurysm (AA), and amyloidosis) based on ICD-coding were analyzed for both a possible association between PES and lifespan, as well as PES and specific systemic diseases. FINDINGS: In the cardiovascular group, PES was not associated with an alteration in longevity. The subgroups acute myocardial infarction and other cardiovascular diseases revealed significantly reduced and increased lifespan, respectively, compared to the rest of the population. These deviations were independent of PES. The impact of PES on the neoplasm group showed that PES-positive persons lived 1·81 years (p < 0·001) longer than PES-negative persons. No significant differences in the PES prevalence were found in any of the cause of death diagnostic groups. INTERPRETATIONS: The present study suggests that lifespan reduction due to neoplasia is nullified by PES, and that this phenomenon is not restricted to one specific neoplasm type. Thus, the paradoxical conclusion emerges that PES provides a lifespan benefit to the patient with a neoplasm. For the remaining diagnostic groups, PES was neither associated with an altered lifespan, nor with any cause of death diagnoses.

7.
Acta Ophthalmol ; 96(8): 834-840, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30239138

RESUMO

PURPOSE: To examine levels of oxidative DNA base damage and expression of selected genes and proteins related to DNA damage repair in human limbal epithelium engineered ex vivo. METHODS: Cells were expanded from limbal tissue on cell culture-treated inserts in medium containing fetal bovine serum, recombinant growth factors, hormones and cholera toxin (COM) and in medium with human serum as the single growth-promoting additive (HS). Cells were analysed after two, three and four weeks in culture for DNA strand breaks and oxidized purine bases (Comet assay using the enzyme formamidopyrimidine DNA glycosylase, Fpg) and for expression of DNA repair enzymes APE1, OGG1 and Polß by in situ hybridization (ISH) and by immunohistochemistry (IHC). RESULTS: Levels of strand breaks were substantial while levels of net Fpg-sensitive sites (8-oxoguanine and ring-opened FaPy bases) were relatively low in cells engineered in COM and in HS. Both types of medium were found to support expression of base excision repair (BER) enzymes APE1, OGG1 and Polß at the gene level. At the protein level, expression of APE1 and OGG1 was noticeable in both conditions while expression of Polß was low. CONCLUSION: Our findings indicate low levels of oxidative stress and/or efficient DNA purine base damage repair in human limbal epithelium engineered in a medium with human serum as the single growth-promoting additive as well as in traditional medium with xenobiotics.


Assuntos
Dano ao DNA , DNA/genética , Epitélio Corneano/metabolismo , Proteínas do Olho/metabolismo , Limbo da Córnea/metabolismo , Estresse Oxidativo/fisiologia , Engenharia Tecidual , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Ensaio Cometa , Epitélio Corneano/citologia , Feminino , Humanos , Imuno-Histoquímica , Limbo da Córnea/citologia , Masculino , Pessoa de Meia-Idade
9.
J Glaucoma ; 27 Suppl 1: S4-S11, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29419641

RESUMO

BACKGROUND: From a historical standpoint the epidemiology of exfoliation syndrome (XFS) is one of the most controversial subjects in ophthalmic literature. Current literature abounds with studies on the prevalence of XFS in various ethnic populations and clearly XFS is a common condition, but its true prevalence is difficult to ascertain. Overall, XFS is considered to be the most common identifiable cause of glaucoma worldwide. PURPOSE: This review critically examines the published literature documenting the epidemiological features of XFS and attempts to provide a unified concept concerning existing controversy. METHODS: A critical review of selected literature pertaining to the epidemiology of XFS. RESULTS: It is well established that XFS and the ensuing exfoliative glaucoma have a worldwide prevalence and a progressively increasing age-related incidence. The prevalence of the condition is significantly underestimated. Many past studies have proposed clear geographic variations within and between ethnic groups. In contrast, there has also been some epidemiological evidence suggesting that the prevalence of XFS is similar within various ethnic groups. Published literature fails to address the potential role and impact of suspected exfoliation cases in the reported prevalence figures of the condition. Incidence figures for the condition are limited and vary extensively. Cumulative data have indicated that several, as yet partly understood genetic, ethnic, and environmental factors contribute to the varied prevalence of this condition. CONCLUSIONS: Further understanding on XFS epidemiology is needed. Only a future large prospective study conducted by the same investigators, using similar methodologies for different ethnic populations will prove beyond doubt the hypothesis that significant geographic variations exist. Since patients with exfoliative glaucoma are at significant risk of losing vision it is vital to elucidate the causes and the risk of developing XFS. To reach this goal, it is important to better delineate the early changes of XFS and to focus research efforts on modifiable factors for XFS development.


Assuntos
Síndrome de Exfoliação/epidemiologia , Glaucoma de Ângulo Aberto/epidemiologia , Etnicidade , Geografia , Humanos , Pressão Intraocular , Prevalência
10.
Acta Ophthalmol ; 94(2): 160-4, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26448582

RESUMO

PURPOSE: Ion channels are formed when acetylcholine (ACh) combines with specific receptors on the postsynaptic membrane. We are testing whether this occurs in vitro in corneal epithelial cells when exposed to ACh, using intracellular ascorbic acid (AA) as a tracer. METHODS: The corneal epithelium was separated from Bowman's membrane as an intact sheet with thermolysin (TL). These cells were incubated in a medium containing phospholine iodide (Phi) to block acetylcholinesterase (AChE) activity, and then, five different groups of specimens were examined: the basic level of ACh and AA in the cells was tested in groups I and II, respectively. In groups III-V, the culture medium was supplemented with AA, ACh and ACh+AA, respectively, and following 2 hr of incubation the cells were tested for AA. AA was determined by high-performance liquid chromatography (HPLC) with UV detection, and ACh by LC-MS/MS. RESULTS: The ACh concentration in the corneal epithelial cells was 23.7 ng/mg wet weight. AA values were as follows: preexposure 0.17 mg/g. After exposure to AA, ACh and ACh+AA, the values were 0.30, 0.12 and 0.21 mg/g, respectively. The AA concentration mechanism of the corneal epithelium was intact despite exposure to Phi and ACh. CONCLUSION: The main observation is that the AA content of the corneal epithelium drops in response to ACh exposure. Various explanations are discussed, in particular the possibility that ACh exposure may cause cell membrane leakage through pores (nicotinic receptors). This would be similar to the moderate membrane leakage (depolarization) in neural synapses in response to ACh release. Interesting in vivo consequences may occur when considering that AChE is extremely UV sensitive, as this substance could be a target at which actinic radiation may influence the ACh-AChE complex in this epithelium.


Assuntos
Acetilcolina/administração & dosagem , Agonistas Colinérgicos/administração & dosagem , Epitélio Corneano/efeitos dos fármacos , Animais , Ácido Ascórbico/metabolismo , Bovinos , Cromatografia Líquida de Alta Pressão , Meios de Cultura/metabolismo , Epitélio Corneano/metabolismo , Canais Iônicos/fisiologia , Espectrometria de Massas em Tandem
11.
EBioMedicine ; 2(7): 765-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26288849

RESUMO

BACKGROUND: To compare life span of persons with and without ocular pseudoexfoliation syndrome (PES). METHODS: The study is based on an epidemiological survey conducted in Sør-Trøndelag county, Norway, in 1985-86. All inhabitants over 64 years of age (2109 individuals) were invited. Mortality information was obtained from The Norwegian Institute of Public Health in 2014, by which time 99% of the participants were deceased. RESULTS: When adjusting for age and gender, life span was not statistically different in persons with and without PES. Following the diagnosis of PES, patients' survival was up to, and beyond, 30 years. CONCLUSIONS: Our observations suggest that, despite all the systemic aberrations reported in persons with ocular PES, none or only marginal functional changes are caused in extraocular organs and tissues. The present study supports the notion that systemic PES is not a life-threatening condition.


Assuntos
Síndrome de Exfoliação/mortalidade , Longevidade , Idoso , Idoso de 80 Anos ou mais , Síndrome de Exfoliação/epidemiologia , Humanos , Estimativa de Kaplan-Meier , Noruega/epidemiologia , Prevalência
12.
Acta Ophthalmol ; 93(5): 422-426, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25571763

RESUMO

PURPOSE: To examine the relationship between human corneal and environmental temperature. METHODS: An infrared camera was used to measure the corneal surface temperature in a group of healthy volunteers as well as in an experimental setting with donor corneas and an artificial anterior chamber, employing circulating saline at +37°C. Liquid nitrogen was used to obtain a very low temperature in the experimental setting. High ambient temperature measurements were performed in a sauna. RESULTS: In healthy volunteers, the cornea required at least 20-30 min to adapt to change in ambient temperature. The relationship between corneal and external temperature was relatively linear. At the two extremes, +83°C and -40°C, the corneal temperature was +42°C and +25.1°C, respectively. In the experimental setting, corneal temperature was +24.3°C at air temperature -40°C. CONCLUSION: A rather stable aqueous humour temperature of +37°C and high thermal conductivity of the corneal tissue prevent corneal frostbite even at extremely low ambient temperatures.


Assuntos
Temperatura Corporal/fisiologia , Temperatura Baixa , Córnea/fisiologia , Meio Ambiente , Temperatura Alta , Adaptação Fisiológica/fisiologia , Adolescente , Adulto , Idoso , Clima Frio , Feminino , Voluntários Saudáveis , Humanos , Raios Infravermelhos , Masculino , Pessoa de Meia-Idade , Técnicas de Cultura de Órgãos , Preservação de Órgãos , Fotografação/instrumentação , Condutividade Térmica , Termografia/instrumentação
14.
Acta Ophthalmol Scand ; 85(8): 810-21, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17376188

RESUMO

Pseudoexfoliation syndrome is a risk factor in cataract surgery because of the increased weakness of zonular apparatus and reduced pupillary dilatation. The surgical outcome of using phacoemulsification in the central zone, inducing minimal stress on the zonules, inserting a capsular tension ring in selected cases, and stretching the pupil mechanically in eyes with miotic pupils, may turn out to be uneventful in most cases. Postoperative fibrosis with subsequent shrinkage of the capsule is increased in these eyes, and these centripetal forces will further loosen the zonular fibres. Late in-the-bag intraocular lens dislocation is therefore anticipated to become a growing problem in the future. Despite the dysfunctioning of the blood-aqueous barrier in eyes with pseudoexfoliation syndrome, the frequency of postoperative inflammatory reaction is low due to the improvements made in surgical technique and equipment in recent years. Glaucoma frequently occurs in eyes with pseudoexfoliation syndrome. Compared with primary open-angle glaucoma, optic damage is more pronounced in these eyes at the time of diagnosis and response to medical therapy is poorer. Although responses to argon laser therapy and filtering surgery are roughly similar between the two types of glaucoma, there are indications that primary laser trabeculoplasty has a higher success rate in pseudoexfoliation glaucoma than in primary open-angle glaucoma.


Assuntos
Extração de Catarata , Catarata/etiologia , Síndrome de Exfoliação/complicações , Glaucoma/etiologia , Glaucoma/cirurgia , Procedimentos Cirúrgicos Oftalmológicos , Síndrome de Exfoliação/patologia , Olho/patologia , Cirurgia Filtrante , Humanos , Terapia a Laser , Trabeculectomia
15.
Cornea ; 24(8): 1000-3, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16227851

RESUMO

PURPOSE: To analyze the concentration of acetylcholine (ACh) in the corneal epithelium and aqueous humor of various diurnal and nocturnal mammals. METHODS: The following species were examined: roe deer, cattle, horse, human, moose, sheep, reindeer, wild boar, polecat, lynx, cat, and rat. ACh was determined by liquid chromatography-tandem mass spectrometry. RESULTS: ACh was present in significant amounts in the corneal epithelium of all diurnal mammals, the concentrations varying from one species to the next. By contrast, it was not detected in any of the nocturnal tissue samples. None of the species showed detectable amounts of ACh in the aqueous humor. CONCLUSIONS: The amount of ACh in the corneal epithelium varies from one species to the next, with diurnal species showing significant concentrations and nocturnal species no detectable concentrations.


Assuntos
Acetilcolina/metabolismo , Ritmo Circadiano/fisiologia , Epitélio Corneano/metabolismo , Animais , Humor Aquoso/metabolismo , Gatos , Bovinos , Cromatografia , Epitélio Corneano/citologia , Equidae , Furões , Humanos , Técnicas In Vitro , Lynx , Ratos , Ratos Wistar , Rena , Ovinos , Especificidade da Espécie , Sus scrofa
16.
Dis Aquat Organ ; 55(2): 151-9, 2003 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-12911063

RESUMO

Osmotic cataracts were diagnosed in all of 191 Atlantic salmon Salmo salar L. postsmolts caught during 8 trawl hauls on the western side of the Vøringsplateau, Norwegian Sea, in June 2001. The changes varied from a hazy opacity in the anterior part of the lens to cataracts affecting the whole lens. Severely affected lenses appeared swollen and large vacuoles were visible in the opaque areas. Large vacuoles in otherwise clear lenses were diagnosed in 1 of 4 adult salmon examined. Histologically, widened sutures, vacuolation of lens epithelium and cortex, and proteinaceous lakes subjacent to the epithelium were the most frequent changes, while extensive cortical necroses and epithelial proliferation were seen in a few cases. UV-absorbance of the aqueous humor was determined and levels compared to plasma levels and also to levels in farmed Atlantic salmon of the same developmental stage. Wild salmon generally showed higher levels of protective factors than farmed fish. The osmotic type of cataract diagnosed leads to poor vision and is a potential cause of reduced survival in postsmolts. The cause of the cataracts could not be determined, but defective osmoregulation is suspected.


Assuntos
Catarata/veterinária , Doenças dos Peixes/diagnóstico , Cristalino/patologia , Salmo salar , Animais , Catarata/diagnóstico , Catarata/epidemiologia , Catarata/patologia , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/patologia , Cristalino/efeitos da radiação , Cristalino/ultraestrutura , Noruega , Raios Ultravioleta/efeitos adversos , Equilíbrio Hidroeletrolítico
17.
J Refract Surg ; 19(3): 338-43, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12777030

RESUMO

PURPOSE: To evaluate whether prophylactic systemic ascorbic acid influences the average level of haze and the incidence of late onset corneal haze after photorefractive keratectomy (PRK). METHODS: Two consecutive groups of eyes treated with PRK for myopia with or without astigmatism were retrospectively compared. The patients had been treated similarly, with the exception that systemic ascorbate had been supplied orally in one of the groups. Haze intensity was quantified on a scale from 0 (clear cornea) to 4 (anterior chamber not visible). The diagnostic criterion for late onset corneal haze was a haze grade 2 or higher, occurring 4 to 12 months after surgery. RESULTS: One week, 1, 3, 6, and 12 months after surgery, the group without ascorbate (314 eyes) showed haze of average levels 0.61, 0.51, 0.50, 0.32, 0.10, respectively, and the group with ascorbate (201 eyes) showed haze of average levels 0.38, 0.18, 0.16, 0.09, 0.06, respectively. Comparison of the respective values showed a statistically significant difference between the two groups (P<.01) at 1 week, 1, 3, and 6 months. Late onset corneal haze was observed in 11 eyes in the group without ascorbate, and none was observed in the group with ascorbate (P<.02). CONCLUSION: This retrospective nonrandomized clinical study suggests that oral ascorbic acid supplementation may have a prophylactic effect against haze development after PRK. However, routine prophylactic use of ascorbate can be recommended only after a randomized, prospective clinical trial substantiates its efficacy.


Assuntos
Antioxidantes/uso terapêutico , Ácido Ascórbico/uso terapêutico , Opacidade da Córnea/prevenção & controle , Ceratectomia Fotorrefrativa/efeitos adversos , Administração Oral , Adulto , Astigmatismo/cirurgia , Opacidade da Córnea/etiologia , Feminino , Humanos , Lasers de Excimer , Masculino , Pessoa de Meia-Idade , Miopia/cirurgia , Estudos Retrospectivos
18.
Ophthalmic Res ; 35(4): 208-16, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12815196

RESUMO

OBJECTIVE: To evaluate the absorbance of ultraviolet radiation (UVR) in the aqueous humor of various animal species in relation to the ambient radiation of their respective habitats, and to identify substances responsible for this absorbance. Representatives of all five classes (fish, amphibian, reptile, bird, and mammal) have been tested. METHODS: Absorbance was recorded using a spectrophotometer. The ascorbic and uric acid concentrations were determined by HPLC, and the amino acid profiles with an automatic analyzer. Screening for potential UV-absorbing substances was performed by HPLC and a total of 12 species were examined, 7 of them birds. RESULTS: UV-absorbing substances in the aqueous humor were proteins, tryptophan, tyrosine and ascorbic and uric acid. In addition, an unknown UV-absorbing component present in bird aqueous humor caused a high, red-shifted UV-absorbance spectrum, particularly in tentatively heavily exposed species such as goose when migrating at 10,000 m altitude. By comparison, the UV absorbance above the 288-nm wavelength was low in the aqueous humor of fish, frogs, aquatic mammals and two ground-living birds. The crocodile, whose aqueous humor contained significant amounts of both ascorbic and uric acid, revealed a concentration mechanism for ascorbic acid. CONCLUSIONS: The UV absorbance of aqueous humor varies considerably from one species to the next, and independent of class. It is noteworthy that the species being at highest risk for high-dose UV exposure, the migrating goose, showed the most red-shifted spectrum.


Assuntos
Humor Aquoso/efeitos da radiação , Raios Ultravioleta , Absorção , Anfíbios , Animais , Humor Aquoso/metabolismo , Ácido Ascórbico/efeitos da radiação , Aves , Cromatografia Líquida de Alta Pressão , Proteínas do Olho/efeitos da radiação , Peixes , Mamíferos , Répteis , Especificidade da Espécie , Espectrofotometria Ultravioleta , Triptofano/efeitos da radiação , Tirosina/efeitos da radiação , Ácido Úrico/efeitos da radiação
19.
Invest Ophthalmol Vis Sci ; 44(1): 10-5, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12506049

RESUMO

PURPOSE: To evaluate whether the content of ascorbic acid in the corneal epithelium and aqueous humor reflects seasonal fluctuations in parallel with environmental changes. METHODS: Reindeer, cattle, rabbits, and humans were examined, to cover a broad spectrum of overlapping habitats. Ascorbic acid was determined by high-performance liquid chromatography. The thickness of the corneal epithelium was measured, and the number of cells was counted in the tissue sections. RESULTS: Three groups of reindeer eyes were used, two of them collected during summer, the third group during winter. Ascorbate content did not show seasonal variation in either the corneal epithelium or the aqueous humor, whereas epithelial thickness and number of cells decreased significantly from summer to winter. In cattle, ascorbate content, thickness of the epithelium, and number of cells were lower in animals tended indoors compared with those tended outdoors, whereas ascorbate level in the aqueous humor remained similar in both cases. The rabbit showed significantly reduced ascorbate content in the corneal epithelium but not in the aqueous humor in tarsorrhaphy-treated eyes. This procedure did not change epithelial thickness, but the number of cells was slightly increased. The mean epithelial thickness in human corneas successively decreased with increasing latitude and decreasing radiation exposure from the summer season in Oslo to the midnight sun, polar night, conditions in Tromsø, 10 degrees far north, although the differences did not reach statistical significance. CONCLUSIONS: Ambient radiation is needed to sustain high ascorbic acid concentration in the corneal epithelium. Corneal epithelial thickness and number of cells are prone to seasonal fluctuations regulated by ambient radiation. In contrast, ascorbate content of the aqueous humor is uninfluenced by environmental change. It is suggested that seasonal adaptation of mammalian corneal epithelium in response to variation in ambient radiation may be nature's strategy for countering radiation damage to the eye.


Assuntos
Humor Aquoso/metabolismo , Ácido Ascórbico/metabolismo , Epitélio Corneano/metabolismo , Estações do Ano , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Humor Aquoso/efeitos da radiação , Bovinos , Cromatografia Líquida de Alta Pressão , Epitélio Corneano/efeitos da radiação , Feminino , Humanos , Luz , Masculino , Pessoa de Meia-Idade , Coelhos , Rena , Raios Ultravioleta
20.
Am J Ophthalmol ; 134(6): 879-83, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12470757

RESUMO

PURPOSE: To investigate whether there is a role for ascorbic acid in the development of exfoliation syndrome (XFS). DESIGN: A case-control study was undertaken that included consecutive patients with and without XFS in whom cataract surgery was indicated. Patients with ophthalmic conditions other than XFS and conditions that may influence ascorbic acid levels were excluded. METHODS: A prospective institutional study was undertaken. A small volume of aqueous humor was aspirated at the beginning of phacoemulsification cataract surgery. Eighty aqueous samples, 40 samples from 40 eyes of 40 cataract patients with XFS and 40 samples from 40 eyes of 40 age matched cataract patients without XFS, were collected and analyzed. Ascorbic acid concentration was evaluated in the aqueous samples with a microplate assay method. RESULTS: The mean +/- SD concentration of ascorbic acid in the aqueous from patients with XFS (0.86 +/- 0.43 mM; range, 0.12 to 1.7 mM) was significantly lower than the concentration of ascorbic acid found in the aqueous of age-matched control patients (1.15 +/- 0.50 mM; range 0.42 to 3.1 mM; P =.0068). Total mean protein concentration was found to be significantly higher in the XFS group (481.1 +/- 196.8 pg/dl versus 336.3 +/- 86.4 pg/dl in the controls; P <.0001). Nevertheless, no correlation could be established between ascorbic level and protein concentration. CONCLUSIONS: A significantly reduced mean level of ascorbic acid was observed in the aqueous humor of patients with XFS. In view of the fact that ascorbic acid is a major protective factor against free radical action, a role for free radical action is possible in the pathobiology of XFS.


Assuntos
Humor Aquoso/metabolismo , Ácido Ascórbico/metabolismo , Síndrome de Exfoliação/metabolismo , Idoso , Estudos de Casos e Controles , Catarata/complicações , Humanos , Facoemulsificação , Estudos Prospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...