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PubMed1995

Ocular manifestations of various systemic diseases.

Transsphenoidal encephalocele is associated with tongue-shaped retinochoroidal coloboma and optic disc dysplasia. Non-Graves' orbital polymyositis is associated with giant cell myocarditis. Ocular embolic disease can result from papillary fibroelastoma of the heart. Cutaneous melanoma can metastasize to the eye in the form of intraocular pigment without a discrete mass leading to heterochromia, glaucoma, and visual loss. Patients with atopic dermatitis are prone to develop retinal detachment similar in configuration to traumatic retinal detachment. The retinal hamartomas in tuberous sclerosis are usually stable, but occasionally the hamartomas show new or increased calcification, and rarely new lesions appear de novo.

Eye Diseases↗
PubMed2005

Alcohol consumption in pregnant, black women is associated with decreased plasma and erythrocyte docosahexaenoic acid.

BACKGROUND: Inner-city, black women are among those groups that are at higher risk for having infants with fetal alcohol spectrum disorders that can include life-long neurobehavioral and cognitive impairments. Chronic alcohol consumption can decrease amounts of docosahexaenoic acid (DHA), a fatty acid that is essential for optimal infant neural and retinal development in a variety of tissues. METHODS: Black women who presented at an inner-city antenatal clinic for their first prenatal visit were recruited into a longitudinal, observational study. Alcohol intake was determined by a structured interview. Participants provided blood specimens and completed food frequency surveys at 24 weeks of gestation, infant delivery, and 3 months postpartum. Fatty acid composition analyses were completed on 307, 260, and 243 for plasma and 278, 261, and 242 erythrocyte specimens at 24 weeks of gestation, delivery, and 3 months postpartum, respectively. RESULTS: Proportion of drinking days at the first prenatal visit was associated with decreased DHA in plasma and erythrocytes throughout the study. This association was the strongest at 24 weeks of gestation. In addition, an interaction between proportion of drinking days at the time of conception and ounces of absolute alcohol per drinking day at the time of conception was detected and demonstrated that, in daily drinkers, high intakes of alcohol are associated with decreased DHA and arachidonic acid (AA) concentrations in plasma. CONCLUSIONS: Frequent and high intakes of alcohol that have been previously associated with fetal alcohol spectrum disorders are also associated with decreased maternal DHA and AA plasma concentrations. The present findings indicate that maternal DHA deficiency is associated with high-risk drinking and may contribute to the mechanism(s) of alcohol-related neurodevelopmental disorders.

Adult↗
PubMed2004

A transgenic mouse model with inducible Tyrosinase gene expression using the tetracycline (Tet-on) system allows regulated rescue of abnormal chiasmatic projections found in albinism.

Congenital defects in retinal pigmentation, as in oculocutaneous albinism Type I (OCA1), where tyrosinase is defective, result in visual abnormalities affecting the retina and pathways into the brain. Transgenic animals expressing a functional tyrosinase gene on an albino genetic background display a correction of all these abnormalities, implicating a functional role for tyrosinase in normal retinal development. To address the function of tyrosinase in the development of the mammalian visual system, we have generated a transgenic mouse model with inducible expression of the tyrosinase gene using the tetracycline (TET-ON) system. We have produced two types of transgenic mice: first, mice expressing the transactivator rtTA chimeric protein under the control of mouse tyrosinase promoter and its locus control region (LCR), and; second, transgenic mice expressing a mouse tyrosinase cDNA construct driven by a minimal promoter inducible by rtTA in the presence of doxycycline. Inducible experiments have been carried out with selected double transgenic mouse lines. Tyrosinase expression has been induced from early embryo development and its impact assessed with histological and biochemical methods in heterozygous and homozygous double transgenic individuals. We have found an increase of tyrosinase activity in the eyes of induced animals, compared with littermate controls. However, there was significant variability in the activation of this gene, as reported in analogous experiments. In spite of this, we could observe corrected uncrossed chiasmatic pathways, decreased in albinism, in animals induced from their first gestational week. These mice could be instrumental in revealing the role of tyrosinase in mammalian visual development.

Albinism, Oculocutaneous↗
PubMed1985

Long-term prognosis of visual field in glaucoma simplex and glaucoma capsular.

The fate of visual fields in 42 eyes with capsular glaucoma followed for 5 to 14 years (mean 9.1 years) and 46 eyes with simple glaucoma followed for 5 to 14 years (mean 10.2 years) was studied retrospectively. In the treatment the IOP levels were around 19.5 mmHg. In both groups the visual field deteriorated in 70-80% of eyes, and 11% of patients became blind. In most cases the progression appeared during the first 4-6 years of follow-up, but in individual cases it did not occur until 8-10 years after the diagnosis. In 26 eyes disc cupping preceded the visual field loss. Five out of 42 eyes with capsular glaucoma developed retinal vein occlusion whereas this occurred in 2 out of 46 eyes with simple glaucoma. Two patients with IOP level of 9 mmHg maintained unchanged visual fields for 6 and 11 years, respectively.

Aged↗
PubMed1985

Vitrectomy in double perforating eye injuries.

The results of 41 consecutive cases of double perforating eye injuries, operated with vitrectomy between December 1975 and December 1982, are reported. Fourteen eyes (34%) obtained a visual acuity of 5/10 or better, and 23 eyes (56%) obtained 5/200 or better. Twenty-eight (68%) developed retinal detachment, and 12 of these were attached by surgery. In this series the pre-operative visual function and the type of injury had a significant effect on the final result. No beneficial effect from early (within 14 days) vitrectomy could be shown.

Adolescent↗
PubMed1985

Experimental scar membranes in the rabbit's vitreous. An autoradiographic and quantitative morphological study.

A morphological and autoradiographic assessment was made of scar tissue development in an experimental rabbit model of proliferative vitreoretinopathy which involves the intravitreal injection of cultured autologous skin fibroblasts. Within a few hours after injection as many as 40% of the cultured cells had autolysed. However, the remaining cells proliferated and formed membranes. The incorporation of [3H] thymidine was maximal at 1 week. Between 2 and 4 weeks spindle-shaped myofibroblasts were prominent, and this form of fibroblast has been considered to have an important role in scar tissue contraction. At the end of 4 weeks it was noted that all eyes had developed retinal detachments. Subsequently the membranes became progressively more fibrous and lipid-like material accumulated in the cytoplasm of many cells. The findings were discussed in relation to the use of this model to test the effectiveness of various drugs which may be of value in the treatment of proliferative vitreoretinopathy.

Animals↗
PubMed1991

Modulation of the affinity of integrin alpha IIb beta 3 (GPIIb-IIIa) by the cytoplasmic domain of alpha IIb.

Intracellular signaling alters integrin adhesive functions in inflammation, immune responses, hemostasis, thrombosis, and retinal development. By truncating the cytoplasmic domain of alpha IIb, the affinity of integrin alpha IIb beta 3 for ligand was increased. Reconstitution with the cytoplasmic domain from integrin alpha 5 did not reverse the increased affinity. Thus, the cytoplasmic domain of the alpha subunit of GPIIb-IIIa controls ligand binding affinity, which suggests mechanisms for inside-out transmembrane signaling through integrins. These findings imply the existence of hitherto unappreciated hereditary and acquired thrombotic disorders in humans.

Amino Acid Sequence↗
PubMed1989

Mutations in the RB1 gene and their effects on transcription.

Inactivation of both alleles of the RB1 gene during normal retinal development initiates the formation of a retinoblastoma (RB) tumor. To identify the mutations which inactivate RB1, 21 RB tumors isolated from 19 patients were analyzed with the polymerase chain reaction or an RNase protection assay or both. Mutations were identified in 13 of 21 RB tumors; in 8 tumors, the precise errors in nucleotide sequence were characterized. Each of four germ line mutations involved a small deletion or duplication, while three somatic mutations were point mutations leading to splice alterations and loss of an exon from the mature RB1 mRNA. We were unable to detect expression of the mutant allele in lymphoblasts of three bilaterally affected patients, although the mutation was present in the genomic DNA and transcripts containing the mutations were obvious in the RB tumors in the absence of a normal RB1 allele. The variations in the level of expression of mutant transcripts suggest deregulation of RB1 transcription in the absence of a functional RB1 gene product.

Alleles↗
PubMed1998

Internal resection of posterior uveal melanomas.

AIMS: To evaluate the safety and efficacy of internal resection in the treatment of malignant melanoma of the choroid. METHODS: 32 consecutive patients with histopathologically proved malignant choroidal melanomas were treated with internal resection. 29 of the 32 (90.6%) tumours were within 2 disc diameters of the optic nerve or fovea. The surgery was performed at two university centres by one of the authors. Follow up was between 1 and 85 months (mean 40.1 months). RESULTS: Three patients developed distant metastases and died of malignant melanoma (metastatic and mortality rate 9.4%). In one case, distant metastases developed in association with an intraocular recurrence. There have been no other intraocular recurrences. The most common postoperative complication was vitreous haemorrhage, which occurred in 12 patients (37.5%); cataract occurred in eight eyes; and three patients developed retinal detachment postoperatively. Three of the operated eyes have been enucleated (9.4%); a total of four (12.5%) have lost light perception. 10 patients (31.2%) had visual acuities of 6/60 or better and 18 of 32 (56.3%) were between 6/120 and light perception. CONCLUSION: These data suggest that the internal resection of posterior uveal melanomas is a reasonable globe saving management option. This treatment modality is particularly well suited to elevated tumours in close proximity to the optic nerve or fovea.

Adult↗
PubMed1997

Light reduction and the electroretinogram of preterm infants.

AIMS: To examine the effects of light on retinal development and function in preterm infants as measured by the electroretinogram (ERG). Secondary outcomes included visual acuity testing, the incidence of retinopathy of prematurity, and general wellbeing, reflected in feeding tolerance, rate of weight gain, and length of hospital stay. METHODS: Eligibility criteria for enrollment were birthweight < or = 1250 g and gestational age < or = 31 weeks. Sixty one infants were randomly allocated by 6 hours after birth to a control or treatment group which wore 97% light filtering goggles for a minimum of four weeks or until the infant reached 31 weeks postmenstrual age. RESULTS: There were no significant differences between the two groups in the numbers of electroretinograms performed at 36 weeks of postmenstrual age. Although the sample size was not large enough to exclude clinically important differences in secondary outcomes, no significant differences were observed between the groups in visual acuity testing at 4-6 months corrected age, incidence of retinopathy of prematurity, weight gain, or length of stay. CONCLUSION: These data support the safety and feasibility of this intervention. A much larger study will be needed to determine whether light reduction to the eyes of very low birthweight infants will reduce the incidence of retinopathy of prematurity or enhance general well-being.

Electroretinography↗
PubMed2006

Defective carbohydrate metabolism in mice homozygous for the tubby mutation.

Tub is a member of a small gene family, the tubby-like proteins (TULPs), with predominant expression in neurons. Mice carrying a mutation in Tub develop retinal and cochlear degeneration as well as late-onset obesity with insulin resistance. During behavioral and metabolic testing, we found that homozygous C57BL/6J-Tub(tub) mice have a lower respiratory quotient than C57BL/6J controls before the onset of obesity, indicating that tubby homozygotes fail to activate carbohydrate metabolism and instead rely on fat metabolism for energy needs. In concordance with this, tubby mice show higher excretion of ketone bodies and accumulation of glycogen in the liver. Quantitation of liver mRNA levels shows that, during the transition from light to dark period, tubby mice fail to induce glucose-6-phosphate dehydrogenase (G6pdh), the rate-limiting enzyme in the pentose phosphate pathway that normally supplies NADPH for de novo fatty acid synthesis and glutathione reduction. Reduced G6PDH protein levels and enzymatic activity in tubby mice lead accordingly to lower levels of NADPH and reduced glutathione (GSH), respectively. mRNA levels for the lipolytic enzymes acetyl-CoA synthetase and carnitine palmitoyltransferase are increased during the dark cycle and decreased during the light period, and several citric acid cycle genes are dysregulated in tubby mice. Examination of hypothalamic gene expression showed high levels of preproorexin mRNA leading to accumulation of orexin peptide in the lateral hypothalamus. We hypothesize that abnormal hypothalamic orexin expression leads to changes in liver carbohydrate metabolism and may contribute to the moderate obesity observed in tubby mice.

Acetate-CoA Ligase↗
PubMedDate not supplied

The role of 99mTc DMSA renal scintigraphy in Joubert syndrome.

Joubert syndrome is a severe autosomal recessive disorder, which is characterized by hypotonia, impaired psychomotor development, retinal dystrophy with abnormal ocular movements and cerebellar vermis agenesis with dilatation of the fourth ventricle. Joubert syndrome type B is a developmental disorder of the nephronophtisis complex with multiple organ involvement. Although this syndrome is rare, since first described by Joubert et al in 1969, there have been several cases about the components and the chromosomal abnormalities related with it. Here we report 2 patients with Joubert syndrome in whom renal involvement was demonstrated by ultrasonography as renal cystic disorders which represented nephronophtisis. For each patient we performed renal cortical scintigraphy with 99mTc-DMSA ( 99mtechnetium-dimercaptosuccinic acid) which showed bilaterally decreased radiopharmaceutical uptake in kidneys due to tubulointerstitial nephropathy. Scintigraphy may have a great value in the diagnosis and evaluation of the presence and severity of renal involvement in Joubert syndrome since it can evaluate kidney parenchyma and functioning renal tissue.

Child↗
PubMed1975

Blood viscosity factors and occlusive arterial disease in renal transplant recipients.

29 cadaveric renal transplant recipients were assessed clinically for evidence of occlusive arterial disease prior to undergoing blood viscosity studies. Nineteen patients had manifest arterial disease (myocardial infarction, cerebral thrombosis, angina, intermittent claudication, absent peripheral pulses), while ten were free from vascular complications. Patients with arterial disease showed significant elevations of plasma viscosity (p less than 0.005), aggregation of red cells measured both at 37 and 20 degrees C (p less than 0.05), fibrinogen (p less than 0.005), serum triglyceride (p less than 0.01), serum cholesterol (p less than 0.01), erythrocyte sedimentation rate (p less than 0.02), and a significant reduction in the albumin/fibrinogen ratio (p less than 0.005) when compared with those free of disease. Two patients with no apparent vascular disease when investigated were found to have distinctly abnormal blood viscosity factors, and one subsequently developed retinal arterial thrombosis while the other suffered serious damage of the graft within 3 months of viscosity study. When all patients were considered together, significant correlations were found between viscosity of artificial thrombi or aggregation of red cells and fibrinogen level (both p less than 0.05), and serum triglyceride level (both p less than 0.05); and between rigidity of red cells and the parathyroid hormone level (p less than 0.01).

Adult↗
PubMed1978

Mitosis in the nontumorous parts of the retina with retinoblastoma.

Uninvolved retina in the posterior pole in an enucleated eye was examined by electron microscopy for retinoblastoma. A mitotic figure was occasionally found in the outer and inner nuclear layers. The dividing cells were clearly separated from the tumor mass by 450-600 micrometer. They were identified as immature Müller cells based upon the fine structural features. The existence of the dividing cells in the posterior retina after birth was abnormal and indicated immaturity of the retinal development.

Eye Neoplasms↗
PubMed2003

Thyroid hormone action in the absence of thyroid hormone receptor DNA-binding in vivo.

Thyroid hormone action is mediated by thyroid hormone receptors (TRs), which are members of the nuclear hormone receptor superfamily. DNA-binding is presumed to be essential for all nuclear actions of thyroid hormone. To test this hypothesis in vivo, the DNA-binding domain of TR-beta was mutated within its P-box (GS mutant) using gene targeting techniques. This mutation in vitro completely abolishes TR-beta DNA-binding, while preserving ligand (T3) and cofactor interactions with the receptor. Homozygous mutant (TR-betaGS/GS) mice displayed abnormal T3 regulation of the hypothalamic-pituitary-thyroid axis and retina identical to abnormalities previously observed in TR-beta KO (TR-beta-/-) mice. However, TR-betaGS/GS mutant mice maintained normal hearing at certain frequencies and did not display significant outer hair cell loss, in contrast to TR-beta-/- mice. DNA-binding, therefore, is essential for many functions of the TR, including retinal development and negative feedback regulation by thyroid hormone of the hypothalamic-pituitary-thyroid axis. Inner ear development, although not completely normal, can occur in the absence of TR DNA-binding, suggesting that an alternative and perhaps novel thyroid hormone-signaling pathway may mediate these effects.

Alleles↗
PubMedDate not supplied

Phacofragmentation without perfluorocarbon liquid for dislocated crystalline lenses or lens fragments after phacoemulsification.

PURPOSE: To evaluate the clinical outcome of vitrectomy with phacofragmentation without perfluorocarbon liquid (PFCL) in the management of dislocation of the crystalline lens, caused by trauma, hereditary disorders, or hypermature cataracts, and lens fragments due to phacoemulsification. METHODS: A prospective study was conducted to evaluate 30 eyes of 29 patients who had undergone standard pars plana vitrectomy with phacofragmentation without PFCL in the vitreous cavity, for the removal of dislocated crystalline lenses or lens fragments, from January 1998 to July 2000. All cases were followed for more than six months. RESULTS: Final best corrected visual acuity of 0.5 or better increased from 0% preoperatively to 36.7% postoperatively, and 0.2 or better rose to 76.7%. The mean IOP was significant reduced, from 26.35 mmHg to 12.75 mmHg. No intraoperative complications occurred. Although two eyes (6.7%) developed retinal detachment, one (3.3%) had cystoid macular edema (CME) and one (3.3%) had a transient intraocular pressure increase (to 25 mmHg) postoperatively, all others had a favorable outcome. CONCLUSIONS: Standard pars plana vitrectomy with phacofragmentation without PFCL in the vitreous cavity is a safe, simple, and effective method for removing a dislocated crystalline lens or lens fragments, with good visual outcome.

Aphakia, Postcataract↗
PubMedDate not supplied

Endogenous endophthalmitis by Propionibacterium acnes associated with leflunomide and adalimumab therapy.

PURPOSE: To report a case of unusual endogenous endophthalmitis associated with the use of leflunomide and adalimumab. METHODS: A 48-year-old woman on treatment with leflunomide and adalimumab for rheumatoid arthritis developed an endogenous endophthalmitis caused by Propionibacterium acnes. Diagnosis was confirmed by polymerase chain reaction and positive cultures. The patient underwent surgical treatment and intravitreal vancomycin, but the eye developed retinal fibrosis and untreatable retinal detachment. RESULTS: This report of endogenous endophthalmitis associated with the use of anti-tumor necrosis factor alpha (anti -TNF-a) drugs is consistent with those in the literature. P. acnes may induce pathologic reactions in compromised patients and cause endophthalmitis, but only after ocular surgery or in intravenous drug users. The Naranjo probability scale indicated a probable relationship between the drugs and the infection. CONCLUSIONS: Awareness of atypical infectious conditions in patients on anti-TNF-a drugs is critical for early diagnosis and good outcome.

Adalimumab↗
PubMed1998

Visual activation in infants and young children studied by functional magnetic resonance imaging.

The purpose of this study was to determine whether visual stimulation in sleeping infants and young children can be examined by functional magnetic resonance imaging. We studied 17 children, aged 3 d to 48 mo, and three healthy adults. Visual stimulation was performed with 8-Hz flickering light through the sleeping childs' closed eyelids. Functional magnetic resonance imaging was performed with a gradient echoplanar sequence in a l.5-T magnetic resonance scanner. Six subjects were excluded because of movement artifacts; the youngest infant showed no response. In 10 children, we could demonstrate areas of signal decrease during visual stimulation in the occipital cortex (mean decrease 2.21%), contrary to the signal increase observed in the adult controls (mean increase 2.82%). This decrease may be due to a higher proportional increase in oxygen extraction compared with increase in cerebral blood flow during activation. The different response patterns in young children and adults can reflect developmental or behavioral differences. Localization of the activation seemed to be age-dependent. In the older children and the adults, it encompassed the whole length of the calcarine sulcus, whereas it was restricted to the anterior and medial part of the calcarine sulcus in the younger infants. This may reflect a different functional organization of the young child's visual cortex or the on-going retinal development.

Adult↗