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T Kivelä

Publications and source records attributed to T Kivelä.

At least 37 records · Page 2Linked to original sources
PubMed2000

Exfoliation syndrome and exfoliation glaucoma.

Exfoliation syndrome abnormal deposition in the anterior segment of the eye of an unknown substance thought to be related to elastic fibres and basement membrane components is associated with accelerated cataract progression. increased frequency of intraoperative and postoperative complications and increased risk for glaucoma and. therefore, is a clinically important finding. A clear association has been shown with age. The syndrome occurs worldwide but its prevalence seems to vary from country to country. The best-known sign of exfoliation syndrome is deposits of greyish-white material on the anterior lens surface. Sometimes exfoliation material can also be seen at the pupillary border, on the anterior iris surface, corneal endothelium, and on the anterior vitreous face. When clinically detected, exfoliation syndrome is somewhat more often unilateral than bilateral. According to recent investigations clinically unilateral exfoliation syndrome is probably never truly unilateral but rather asymmetric, because exfoliation material has been detected ultrastructurally and immunohistochemically around iris blood vessels of the nonexfoliative fellow eyes. Indeed, electron microscopy identifies in various organs of patients with exfoliation syndrome fibrils similar to those seen in intraocular exfoliation deposits. Other clinical signs associated with exfoliation syndrome are pigment dispersion, transillumination defects of the iris and reduced response to mydriatics. In unilateral exfoliation syndrome, intraocular pressure (IOP) of the exfoliative eye is approximately 2 mmHg higher than IOP of the nonexfoliative fellow eye. Whether elevated IOP, vascular changes or exfoliation syndrome itself is the main factor causing optic nerve head damage and conversion of an exfoliative eye to glaucomatous, is not known. Glaucoma in the exfoliation syndrome has been shown to have a more serious clinical course than in primary open-angle glaucoma (POAG). At the time of diagnosis, IOP and its diurnal variation are generally higher and visual field defects tend to be greater in exfoliation glaucoma than in POAG. Because the decrease in lOP variation and lowering of the mean IOP level has been shown to improve visual field prognosis more in exfoliation glaucoma than in POAG, the glaucomatous process is considered to be more pressure-related in exfoliation glaucoma. Furthermore, progression of optic disc damage has been shown to be similar in exfoliation glaucoma and POAG when lOPs are lowered to a comparable level by the treatment. However, vascular disturbances in the posterior segment of the eye might after all be of equal importance in these two types of glaucoma; optic disc haemorrhages and venous occlusions have been reported to be as frequent in exfoliation glaucoma as in POAG. Perhaps in exfoliation glaucoma circullatory disturbances combined with high IOP lead to a particularly relentlessly progressing form of the disease.

Animals↗
PubMed2000

Immunolocalization of transforming growth factor-beta1 and tenascin in human secondary cataract.

PURPOSE: This study was carried out to investigate the distribution of transforming growth factor-beta1 (TGF-beta1) and the extracellular matrix (ECM) glycoprotein tenascin in secondary cataract and anterior subcapsular cataract. METHODS: Twenty-four pseudophakic human eyes with secondary cataract, obtained at autopsy 1 d to 10 yr (mean 2.4 yr) after cataract surgery, were studied. Additionally, a specimen from an anterior subcapsular cataract was included. Immunohistochemistry was used to localize TGF-beta1 and tenascin in secondary cataract and in anterior subcapsular cataract. RESULTS: Polyclonal antibody to TGF-beta1 immunolabelled spindle-shaped cells in the plaques of secondary cataract in all eyes. Instead, the cells present in Soemmering's ring cataract were not labelled. The ECM in the plaques of secondary cataract was immunoreactive for tenascin in all eyes. In anterior subcapsular cataract spindle-shaped cells and ECM showed similar immunoreactivity. CONCLUSION: Spindle-shaped cells that are immunolabelled with TGF-beta1 and ECM showing tenascin-like-immunoreactivity are present in secondary cataract and in anterior subcapsular cataract, thus implicating a possible role in secondary cataract.

Aged↗
PubMed2000

Search for autoantibodies against the HNK-1 carbohydrate epitope in the human eye in intermediate uveitis.

PURPOSE: Molecules bearing the immunogenic HNK-1 epitope are present in the inner connective tissue layer and epithelia of the ciliary body. We investigated whether autoantibodies to these molecules can be detected in patients with intermediate uveitis, which affects the ciliary body. METHODS: Serum was collected from 9 patients with intermediate uveitis, and from 6 controls with idiopathic iritis and 3 controls with sarcoid uveitis, representing nongranulomatous and granulomatous uveitis, respectively. The sera were used as polyclonal antibodies to immunostain 3 formalin-fixed, paraffin-embedded normal human donor eyes by the avidin-biotinylated peroxidase complex method. RESULTS: No immunostaining in the ciliary body could be detected using the sera from patients with intermediate uveitis or from the controls. Serum within blood vessels was nonspecifically immunolabelled with the secondary anti-human anti-serum. CONCLUSION: No autoantibodies against the HNK-1 epitope or other antigens of the ciliary body could be demonstrated in patients with intermediate uveitis. It is unlikely that such autoantibodies against the HNK-1 epitope have a role in intermediate uveitis.

Adolescent↗
PubMed2000

Mutations in KERA, encoding keratocan, cause cornea plana.

Specialized collagens and small leucine-rich proteoglycans (SLRPs) interact to produce the transparent corneal structure. In cornea plana, the forward convex curvature is flattened, leading to a decrease in refraction. A more severe, recessively inherited form (CNA2; MIM 217300) and a milder, dominantly inherited form (CNA1; MIM 121400) exist. CNA2 is a rare disorder with a worldwide distribution, but a high prevalence in the Finnish population. The gene mutated in CNA2 was assigned by linkage analysis to 12q (refs 4, 5), where there is a cluster of several SLRP genes. We cloned two additional SLRP genes highly expressed in cornea: KERA (encoding keratocan) in 12q and OGN (encoding osteoglycin) in 9q. Here we report mutations in KERA in 47 CNA2 patients: 46 Finnish patients are homozygous for a founder missense mutation, leading to the substitution of a highly conserved amino acid; and one American patient is homozygous for a mutation leading to a premature stop codon that truncates the KERA protein. Our data establish that mutations in KERA cause CNA2. CNA1 patients had no mutations in these proteoglycan genes.

Amino Acid Sequence↗
PubMed1999

Screening for metastatic malignant melanoma of the uvea revisited.

BACKGROUND: The purpose of the current study was to assess the value of routine imaging and liver function tests in detecting metastases from malignant melanoma of the uvea. METHODS: Forty-six consecutive patients diagnosed with metastatic uveal melanoma between 1985 and 1996 who had participated in a screening program that included annual liver function tests (LFT), chest X-ray, and abdominal ultrasonography (US) were eligible for this retrospective cohort study. Main outcome measures were the sensitivity of screening tests, presence of symptoms, recurrence free interval, and metastatic burden. RESULTS: Metastases were diagnosed in 74% of patients (95% confidence interval [95% CI], 59-86) at screening and in 26% (95% CI, 14-41) when the patient consulted a physician because of symptoms that developed before the next scheduled visit. Of all the patients, 59% (95% CI, 43-73) were asymptomatic, and 80% (95% CI, 66-91) had only hepatic metastases. The median recurrence free interval, greatest dimension of the largest metastasis, and metastatic burden of the two groups did not differ. US was diagnostic in 78% (95% CI, 64-89), at least 1 LFT test was abnormal in 70% of patients (95% CI, 54-82), and a chest X-ray was abnormal in 2% of patients (95% CI, 0-12). LFTs and US did not reveal hepatic metastases in 33% and 4% of patients, respectively. The sensitivity of individual LFTs ranged from 0.27 to 0.67, and their specificity from 0.90 to 0.96, with lactate dehydrogenase being the most sensitive LFT used. CONCLUSIONS: The authors believe that annual screening with LFTs and abdominal US will identify 59% of patients while they are still asymptomatic and that semiannual screening will detect >95% of such patients. Chest X-ray has a very low yield and is recommended only at baseline to exclude metastatic disease to the eye and if pulmonary symptoms develop.

Adult↗
PubMed1999

Microvascular loops and networks as prognostic indicators in choroidal and ciliary body melanomas.

BACKGROUND: Malignant melanoma of the ciliary body and choroid of the eye is a tumor that disseminates frequently, and 50% of the diagnosed patients die within 10 years. We investigated the hypothesis that, by histopathologic analysis of the arrangement of microvessels (i.e., small blood vessels) in loops and networks, we might be able to differentiate better those patients with a favorable prognosis from those with a poor prognosis. METHODS: We conducted a population-based, retrospective cohort study of melanoma-specific and all-cause mortality for 167 consecutive patients who had an eye surgically removed because of malignant choroidal or ciliary body melanoma during the period from 1972 through 1981. Microvascular loops and networks were evaluated independently by two pathologists who were unaware of patient outcome. RESULTS: Microvascular patterns could be assessed in 134 (80%) of 167 melanoma specimens. The 10-year probability of melanoma-specific survival was worse if microvascular loops (0.45 versus 0.83; two-sided P<.0001) and networks (0.41 versus 0.72, two-sided P<.0001) were present. In multivariate Cox regression analysis of melanoma-specific survival, the hazard ratios were 1.66 (95% confidence interval [CI] = 1.19-2.30) for the presence of loops and networks as a combined three-category variable, 2.36 (95% CI = 1.37-4.05) for the presence of epithelioid cells, 1.11 (95% CI = 1.03-1.19) for the largest basal tumor diameter (evaluated as a continuous variable), and 2.14 (95% CI = 1.25-3.67) for ciliary body involvement. CONCLUSIONS: Patients with malignant uveal melanoma who have a favorable prognosis can be distinguished from those with a poor prognosis by histopathologic analysis of microvascular patterns in uveal melanoma tumor specimens.

Adolescent↗
PubMed1999

Unilateral capsular glaucoma after long-standing bilateral pigmentary glaucoma.

In 1964 we treated a 42-year-old woman diagnosed to have classical bilateral pigment dispersion syndrome combined with an intraocular pressure (IOP) of up to 28 mmHg in both eyes. The patient now has a daughter, also with pigment dispersion syndrome. Miotic treatment brought the IOPs to normal, and 8 years later when the disease was in the inactive phase all treatment could be discontinued. At the age of 67 years, exfoliation deposits became visible in the right eye only, but the IOPs were still below 21 mmHg. Four years later, the pressure of the right eye rose to 31 mmHg. During the next few years all available IOP-lowering medications and laser trabeculoplasty failed, and finally trabeculectomy had to be performed to keep the pressure of the right eye under control and to halt visual field changes, which had already appeared. This case illustrates that development of exfoliation syndrome may take place irrespective of pigment dispersion, and that their simultaneous occurrence may lead to an IOP rise that is resistant to medical therapy and laser trabeculoplasty. It additionally provides further clues to the pathogenesis of capsular glaucoma.

Adult↗
PubMed1999

Trilateral retinoblastoma: a meta-analysis of hereditary retinoblastoma associated with primary ectopic intracranial retinoblastoma.

PURPOSE: To obtain refined knowledge regarding trilateral retinoblastoma (TRb), which is a syndrome that consists of hereditary retinoblastoma associated with an intracranial neuroblastic tumor. MATERIALS AND METHODS: Using a systematic literature review, we contacted authors to obtain missing information. Data from 106 children were used in a meta-analysis including frequency distributions and Kaplan-Meier survival curves. RESULTS: TRb showed no sex predilection. Median age at diagnosis of retinoblastoma was 5 months (range, 0 to 29 months); age at diagnosis was younger among 47 children (47%) with familial retinoblastoma compared with age at diagnosis among 52 children (53%) with sporadic retinoblastoma (2 v 6.5 months, P <.0001). TRb usually affected the second or third generation with retinoblastoma. Median time from retinoblastoma to TRb was 21 months (range, 6 months before to 141 months after); time to TRb was longer for 78 (77%) pineal tumors compared with 23 (23%) suprasellar tumors (32 v 6.5 months, P <.0001). The size (27 v 32 mm, P =.57) and prognosis (survival of 9 v 8 months, P =.91) of pineal and suprasellar tumors were similar. TRb was detected earlier (1 v 22 months, P =.0007) and the child survived longer if neuroimaging was routinely performed (16 v 8 months, P =.001), but age at death was similar (36 v 37 months, P =.98). Cumulative 5-year survival (which was likely to indicate cure) was 27% (v 0%) if screening was undertaken. All children whose TRb exceeded 15 mm in size died. CONCLUSION: The family history, age at diagnosis, and laterality of retinoblastoma in children with TRb resembled that of ordinary hereditary retinoblastoma. Suprasellar TRb were diagnosed earlier, and may arise earlier, than pineal TRb. Screening by neuroimaging could improve the cure rate if cases of TRb were detected when tumors were 15 mm or smaller in size.

Age of Onset↗
PubMed1999

Microvascular density in predicting survival of patients with choroidal and ciliary body melanoma.

PURPOSE: Although malignant uveal melanoma disseminates predominantly hematogenously because of the absence of intraocular lymphatics, consensus about prognostic impact of microvascular density (MVD) has not been reached. This study was undertaken to investigate whether MVD, microvascular patterns, or both determine prognosis of uveal melanoma. METHODS: A population-based retrospective cohort study of melanoma-specific and all-cause mortality of 167 consecutive patients who had an eye enucleated because of choroidal or ciliary body melanoma from 1972 through 1981 was conducted. MVD was determined by counting tumor vessels in a masked fashion from areas of highest vessel density after immunostaining for CD34 epitope, factor VIII-related antigen (FVIII-RAg), and alpha-smooth muscle actin (SMA). Kaplan-Meier and Cox regression analyses of survival were performed. The association between MVD and tumor size and location, cell type, and microvascular patterns was assessed. RESULTS: MVD could be determined from 134 of 167 melanomas (80%). Based on globally highest count obtained with antibodies to CD34, MVD ranged from 5 to 121 vessels/0.313 mm2 (median, 40) and its association with presence of microvascular loops and networks (P = 0.0006), epithelioid cells (P = 0.028), and largest basal tumor diameter (P = 0.0029) was statistically significant. The 10-year melanoma-specific mortality increased with MVD (0.09, 0.29, 0.59, and 0.64, according to quartiles; P < 0.0001), as did all-cause mortality (P = 0.0022). Equivalent results were obtained with immunostaining for FVIII-RAg, whereas MVD obtained with antibodies to SMA was not associated with prognosis. Cox regression showed a hazard ratio of 2.45 (95% CI, 1.43-4.18) for presence of epithelioid cells, 1.11 (95% CI, 1.03-1.20) for largest basal diameter, 1.23 (95% CI, 1.06-1.43) for square root-transformed MVD, and 1.51 (95% CI, 1.09-2.10) for presence of loops and networks, all of which independently contributed to prognosis. CONCLUSIONS: The findings support the theory that both MVD and microvascular patterns contribute independently to prognosis in uveal melanoma in addition to cell type and size of the tumor.

Actins↗
PubMed1998

Diabetes insipidus and blindness caused by a suprasellar tumor: Pieter Pauw's observations from the 16th century.

Tumors in the suprasellar region may cause both visual and endocrinologic symptoms. This association, well known to modern physicians, was established during the 19th century. However, we have identified a 16th-century autopsy report, written by the Dutch professor of anatomy Pieter Pauw (1564-1617), which describes an 18-year-old girl who developed marked polyuria and subsequently became totally blind from a cystic tumor compressing the optic chiasm. Based on prevailing theories on the nature of diabetes, Pauw attributed the disease to the kidneys. Undoubtedly, however, his lucid report is the earliest known account of diabetes insipidus caused by an arachnoid cyst, the Rathke cleft cyst, or craniopharyngioma in the region of the pouch of Rathke. The description also gives insights into the role of anatomic dissections in late 16th-century northern Europe.

Anatomy↗
PubMed1998

Comparative immunohistochemical oestrogen receptor analysis in primary and metastatic uveal melanoma.

BACKGROUND: The investigation reported here was carried out to determine the oestrogen receptor status of metastatic and primary uveal melanomas. METHODS: A series of 23 primary and 24 metastatic formalin-fixed paraffin-embedded choroidal melanomas were analysed immunohistochemically with the monoclonal antibody (MAb) 1D5 using the avidin-biotinylated peroxidase method and antigen retrieval with microwaves. Melanophages were identified with MAb PG-M1 to macrophages. RESULTS: None of the primary or metastatic melanomas contained tumour cells that would have shown a nuclear immunoreaction for oestrogen receptors with MAb 1D5. However, in 20 of the 23 primary tumours and in 14 of the 24 metastases a variable number of infiltrating cells showed a strong positive cytoplasmic immunoreaction with MAb 1D5. The cells contained pigmented cytoplasmic granules that resisted bleaching of melanin and their cytoplasm was strongly labelled with MAb PG-M1, identifying them as cross-reacting macrophages. CONCLUSION: Oestrogen receptors can not be used as a prognostic indicator if anti-oestrogen therapy is considered for treatment of metastatic uveal melanoma. However, because anti-oestrogens also act by other mechanisms on both tumour and host tissues, the lack of oestrogen receptors does not automatically negate their therapeutic effect in disseminated melanoma.

Antibodies, Monoclonal↗
PubMed1998

Retinal detachment in pseudophakic eyes with and without Nd:YAG laser posterior capsulotomy.

OBJECTIVE: This study aimed to determine whether the characteristics of pseudophakic retinal detachment (RD) differ in eyes with and without a neodymium (Nd):YAG laser capsulotomy to identify features that might help to treat capsulotomy patients better. DESIGN: The study design was a retrospective cohort study of 129 consecutive eyes, 61 with a capsulotomy and 68 control eyes with an intact posterior capsule, in which a primary rhegmatogenous RD developed after a strictly uncomplicated extracapsular cataract extraction and intraocular lens implantation. SETTING: The study was conducted in a primary referral center. MAIN OUTCOME MEASURES: Number, type, and location of retinal breaks and type and extent of RD were measured. RESULTS: Risk factors predisposing to RD did not differ between the capsulotomy and control group. The median interval from cataract surgery to RD was expectedly longer in the capsulotomy group (4.1 years vs. 1.5 years, P < 0.001). The mean number of retinal breaks was larger in the capsulotomy group (1.7 vs. 1.1, P = 0.05), especially in upper quadrants (82 of 103 vs. 48 of 77, P = 0.024). Capsulotomy eyes also had a trend to have more atrophic holes that caused detachment relative to horseshoe breaks (34 of 103 vs. 15 of 77, P = 0.062). The type and extent of RD were similar in the two groups. CONCLUSIONS: This pilot study suggests that atrophic holes, particularly in the superior quadrants, may lead to RD preferentially after posterior capsulotomy. Early identification and treatment of such breaks might decrease the number of pseudophakic detachments after capsulotomy.

Adult↗
PubMed1998

Ophthalmologic findings in long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency caused by the G1528C mutation: a new type of hereditary metabolic chorioretinopathy.

OBJECTIVE: The purpose of the study was to determine the nature and course of ophthalmic abnormalities in long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency, a recently discovered disorder of mitochondrial fatty acid beta-oxidation. STUDY DESIGN: The study design was a cohort (case series). PARTICIPANTS: A retrospective review of the records of 15 children who had died during their first 2 years was performed. Also performed were a longitudinal reanalysis and cross-sectional clinical examination of four long-term survivors aged 5 to 31 years. MAIN OUTCOME MEASURES: Visual acuity, refraction, visual fields, ophthalmoscopy, fluorescein angiography, biometry, corneal topography, electroretinography (ERG), visual-evoked potentials (VEPs), color vision, and dark adaptation were measured. RESULTS: In seven children, ophthalmoscopic findings were within normal limits at 3 days to 13 months of age (median, 4.8 months). In 11 children, a granular retinal pigment epithelium (RPE), with or without pigment clumping in the macula, was seen at 4 months to 5 years of age (median, 9 months). Two long-term survivors, 16 and 31 years of age, eventually had circumscribed atrophy of the choroid, RPE, and retina, which coincided with a posterior staphyloma type 1. They had progressive axial myopia starting at 6 and 12 years of age and later paracentral scotomas leading to poor central vision. They suffered from early difficulty with mesopic vision, glare, and a severe generalized color vision deficiency that started as a tritanomaly. A third survivor was mildly myopic at 5 years of age. All four surviving patients had visually insignificant, flake-like supranuclear opacities in the lens. The ERG initially was normal but deteriorated during the first decade and later was unrecordable. The VEP responses remained fairly normal. Initially, angiography showed no blockade of the choroidal fluorescence because of the thin RPE. Filling of choroidal vessels was delayed, and the choriocapillaris and, later, larger choroidal vessels in the posterior pole became nonperfused. CONCLUSIONS: In LCHAD deficiency, the fundus is normal at birth (stage 1). Soon, however, pigment dispersion occurs in the RPE (stage 2), followed by circumscribed chorioretinal atrophy, occlusion of choroidal vessels, and deterioration of central vision, often with relative sparing of the peripheral fundus (stage 3). Finally, posterior staphylomas and central scotomas may develop (stage 4). Developmental cataract, progressive myopia, and deterioration of visual fields and color vision are new findings in LCHAD deficiency. The chorioretinopathy and abnormal ERG precede the development of myopia and posterior staphyloma, which, in turn, coincide with the loss of macular vision. The authors postulate that the RPE or choriocapillaris is primarily affected. Awareness of the characteristic ocular features is important because of an opportunity for dietary treatment, genetic counseling, and prenatal diagnosis.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1998

Structure, development and function of cytoskeletal elements in non-neuronal cells of the human eye.

The cytoskeleton, of which the main components in the human eye are actin microfilaments, intermediate filaments and microtubules with their associated proteins, is essential for the normal growth, maturation, differentiation, integrity and function of its cells. These components interact with intra- and extracellular environment and each other, and their profile frequently changes during development, according to physiologic demands, and in various diseases. The ocular cytoskeleton is unique in many ways. A special pair of cytokeratins, CK 3 and 12, has apparently evolved only for the purposes of the corneal epithelium. However, other cytokeratins such as CK 4, 5, 14, and 19 are also important for the normal ocular surface epithelia, and other types may be acquired in keratinizing diseases. The intraocular tissues, which have a relatively simple cytoskeleton consisting mainly of vimentin and simple epithelial CK 8 and 18, differ in many details from extraocular ones. The iris and lens epithelium characteristically lack cytokeratins in adults, and the intraocular muscles all have a cytoskeletal profile of their own. The dilator of the iris contains vimentin, desmin and cytokeratins, being an example of triple intermediate filament expression, but the ciliary muscle lacks cytokeratin and the sphincter of the iris is devoid even of vimentin. Conversion from extraocular-type cytoskeletal profile occurs during fetal life. It seems that posttranslational modification of cytokeratins in the eye may also differ from that of extraocular tissues. So far, it has not been possible to reconcile the cytoskeletal profile of intraocular tissues with their specific functional demands, but many theories have been put forward. Systematic search for cytoskeletal elements has also revealed novel cell populations in the human eye. These include transitional cells of the cornea that may represent stem cells on migration, myofibroblasts of the scleral spur and juxtacanalicular tissue that may modulate aqueous outflow, and subepithelial matrix cells of the ciliary body and myofibroblasts of the choroid that may both participate in accommodation. In contrast to the structure and development of the ocular cytoskeleton, changes that take place in ocular disease have not been analysed systematically. Nevertheless, potentially meaningful changes have already been observed in corneal dystrophies (Meesmann's dystrophy, posterior polymorphous dystrophy and iridocorneal endothelial syndrome), degenerations (pterygium) and inflammatory diseases (Pseudomonas keratitis), in opacification of the lens (anterior subcapsular and secondary cataract), in diseases characterized by proliferation of the retinal pigment epithelium (macular degeneration and proliferative vitreoretinopathy), and in intraocular tumours (uveal melanoma). In particular, upregulation of alpha-smooth muscle actin seems to be a relatively general response typical of spreading and migrating corneal stromal and lens epithelial cells, trabecular cells and retinal pigment epithelial cells.

Cytoskeletal Proteins↗
PubMed1998

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Contact Lenses↗