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A Balmer

Publications and source records attributed to A Balmer.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Uveal effusion syndrome: clinical and ultrastructural aspects].

UNLABELLED: Spontaneous serous detachment of the choroid and ciliary body, together with bullous serous detachment of the retina (uveal effusion syndrome) is a rare but well-defined syndrome frequently associated with nanophthalmos. CASE REPORTS: Based on three cases whose one familial, clinical and ultrastructural characteristics of the syndrome are reviewed and the role of ultrasonic biomicroscopy (UBM) presented. CONCLUSION: The severe and potentially blinding complications encountered after any surgery on these eyes make the recognition of the classical clinical signs and symptoms of the syndrome particularly important. In this context, UBM represents an interesting new tool in terms of diagnosis and pathophysiology understanding.

Ciliary Body↗
PubMed1996

[Medullo-epithelioma: presentation of 3 cases].

Three cases of medullo-epithelioma are reported from a study of almost 350 cases of retinoblastomas or pseudo-retinoblastomas. The cases concern one female and two male children of 1,5, 2,5 and 6 years of age respectively at the time of diagnosis. Suspected of carrying retinoblastoma, two of the children were enucleated. Histological examination revealed the presence of a benign medullo-epithelioma in one case and a malignant condition in the other. The third case was treated by brachytherapy which led to total destruction of the tumor. A new iridian focus opposite the original tumor appeared one year later and was in turn destroyed by cobalt applicator.

Brachytherapy↗
PubMed1996

Sex mutation ratio in retinoblastoma and retinoma: relevance to genetic counseling.

PURPOSE AND METHOD: The parental origin of initial somatic and germline mutations (M1) in the retinoblastoma gene (RB1) was explored in 36 retinoblastoma (Rb) and 5 retinoma patients, of which 16 were presumably non-hereditary and 25 were hereditary. By this approach the male:female mutation ratio was determined by the gender quotient of mutation origin. RESULTS: The male to female mutation ratio in hereditary Rb was 19:2, which is consistent with a significant bias towards paternal origin of germline mutation. This ratio was of 5:2 in non-hereditary Rb which is not significant. DISCUSSION: Together with the published data, these results support a preferential paternal mutagenesis in hereditary Rb, but appear to reject paternal genomic imprinting at the RB1 locus as previously proposed in non-hereditary Rb. Genetic counseling in sporadic Rb may be substantially improved by the identification of the parental origin of initial mutation.

Cohort Studies↗
PubMed1995

[New retinal tumors in hereditary retinoblastoma].

364 eyes from 230 patients with retinoblastoma diagnosed and treated at the Lausanne University Eye Clinic from 1964 to June 1994 were retrospectively analyzed with respect to the risk of developing new tumour foci following initial therapy. Among them, 119 eyes from 90 hereditary affected patients were included, consisting of 86 bilateral cases and 4 unilateral cases. The mean follow-up was 65.5 months (5.5 years). A total of 46 new retinal tumours were detected in 21 patients. These new tumours had a size less than 1 disc diameter in 75% and were peripherally located in 78% of the cases, with a statistically significant preference for the horizontal meridians. No new tumours developed in the macular area. 50% appeared in children younger than 1 year and 80% before 2 years of age. 50% of the eyes with recurrences developed new tumours before 7.5 months following diagnosis, and 75% before 14 months. All patients showing recurrences did so before the age of 4.5.

Adolescent↗
PubMed1995

[Clinical applications of molecular diagnosis of retinoblastoma ain 15 families].

PURPOSE: In 40% retinoblastoma (Rb) results from a hereditary mutation of the Rb susceptibility gene (RB1). In this study, we tested the usefulness of intragenic DNA analysis for ophthalmologic follow-up in affected families. METHODS: Molecular analysis was performed on 103 DNA samples of 15 Rb families. We used 7 intragenic polymorphic markers and one within the ESD gene for mutation linkage analysis. FINDINGS: DNA analysis was informative in 88% of relatives at risk of developing Rb. Among them, the presence of a mutated RB1 allele was excluded in 46%, while 29% were unaffected carriers and 25% had inherited the Rb predisposition. CONCLUSION: In the majority of familial Rb, the DNA analysis allows the identification of children carrying a RB1 mutation and who will need a close ophthalmologic follow-up under general anesthesia. When the mutated gene is absent, ophthalmological examination under narcosis is unnecessary. Finally, identification of asymptomatic carriers improve the accuracy of genetic counselling.

Adult↗
PubMed1994

[Unusual presentation of retinoblastoma].

Among the 185 retinoblastoma patients seen at the Lausanne Retinoblastoma Clinic from 1963-1993, 24 (14%) first presented with another sign than classical leukocoria (60.5%) or strabismus (21.5%). Most of these atypical signs were related to inflammatory complications of unrecognized retinoblastoma; they consisted of low vision (1.5%), hypopyon (2%), ocular redness and pain (1.5%), ocular redness and buphtalmia (1.5%), as well as photophobia and headaches (1.5%). The presence of unexplained chronic ocular signs during childhood should always raise the possibility of an underlying retinal malignancy.

Child↗
PubMed1993

Pseudo low penetrance in retinoblastoma. Fortuitous familial aggregation of sporadic cases caused by independently derived mutations in two large pedigrees.

OBJECTIVE: The disparate occurrence of few cases of retinoblastoma in the same extended pedigree confronts us with the unsolved problem of a low-penetrant autosomal-dominant trait vs fortuitous familial aggregation of sporadic cases. Determination as to whether the disease arises from a common inherited mutation or sporadic mutations has important implications for genetic counseling. This is illustrated in this report of two presumed low-penetrant retinoblastoma pedigrees characterized by two distantly affected relatives connected through apparently healthy carriers. DESIGN: We mathematically modeled the inheritance patterns and calculated the a priori relative probabilities of heredity with low penetrance vs chance occurrence of independent mutations for each pedigree. The derived odds clearly show that the disease, which occurred twice in each family, most likely resulted from unrelated mutations. To prove this, extensive DNA testing was conducted, including determination of intragenic RB1 DNA sequence polymorphisms and screening for mutation using the polymerase chain reaction coupled with single-strand conformation polymorphism analysis. PATIENTS: All living key members from both pedigrees were included. RESULTS: Consistent with our initial expectation, there was no common intragenic haplotype or common germ-line mutation that segregated with the disease phenotype in either of these two families. CONCLUSIONS: We therefore conclude that collateral incidence of retinoblastoma in these two pedigrees occurred by chance and not according to autosomal-dominant inheritance with low penetrance. Furthermore, our data provide the first evidence, to our knowledge, that related individuals may have independent mutations involving an identical gene locus, giving rise to an artefactual inheritance pattern.

Child, Preschool↗
PubMed1993

Hypofractionation in retinoblastoma: an increased risk of retinopathy.

Forty-four eyes in 38 children were treated between 1963 and 1991 by external radiotherapy for retinoblastoma. Treatment modalities varied widely during this period; in addition to radiotherapy there was chemotherapy (16/44), photocoagulation (14/44), and laser therapy or cryotherapy (14/44). Treatment technique and dose fractionation also varied widely; lateral beam technique (39/44) versus anterior or anterior/lateral beam; doses per fraction ranged from 1 to 4.5 Gy, total doses from 30 to 61.5 Gy, and overall times from 22 to 49 days. Patients were followed at 3-month intervals, and actuarial survival at 10 years was 88%, with 62% local control. Ten eyes showed clinical evidence of retinopathy. A multivariate analysis of factors associated with increased risk of retinopathy was carried out using the Cox proportional hazards model and the mixture model of Farewell. The estimated latent time was 17 months (95% confidence interval, 14-20 months). The only factors found to be significantly associated with retinopathy were total dose multiplied by dose per fraction, or total dose normalized to the equivalent total dose in 2-Gy fractions as estimated from the LQ model, and these gave equivalent descriptions. There were trends (not significant) for increased risk of retinopathy when treatments included chemotherapy or photocoagulation, and for decreased risk (also not significant) when cryotherapy was used in conjunction with radiotherapy. No significance could be attached to any of the following: number of sites per eye, Reese-Ellsworth stage, and family history. We conclude that hypofractionation carries a significant risk for retinopathy in the treatment of retinoblastoma.

Child, Preschool↗
PubMed1993

Retinoblastoma. Unusual warning and clinical signs.

Three clinical cases have been chosen to illustrate the pitfalls that can be encountered when warning signs other than leukokoria or strabismus indicate possible retinoblastoma. The first case, a four-year-old boy, was admitted to hospital after an accident, presenting uveitis, glaucoma and a subluxated lens. He was suffering from unilateral retinoblastoma, already exteriorized and the cause of death some months later. The second case, and 11-month-old female child was seen on fundus examination to present a yellowish elevated calcified mass which turned out to be tuberous sclerosis. The third patient, a 43-year-old male, father of two children suffering from retinoblastoma, was found on routine examination to be carrying a partially-calcified retinal tumour. Subsequent haemorrhaging rendered enucleation necessary and microscopic examination confirmed the diagnosis of retinoma. The diagnosis of retinoblastoma should always be kept in mind whenever an intraocular mass is revealed or where there are unexplained atypical ocular signs.

Adolescent↗
PubMed1992

Paternal selection favoring mutant alleles of the retinoblastoma susceptibility gene.

Penetrance and segregation rates of mutant Rb-1 alleles were assessed in all 51 members of eight kindreds with hereditary retinoblastoma by concomitant ophthalmologic examination and determination of seven intragenic restriction fragment length polymorphisms (RFLPs). Penetrance was in the range reported in the literature except for one family in which it was only 42.8%. However, the odds of transmitting a mutant Rb-1 allele from one generation to the next were 25:9 in this population, much above the Mendelian 1:1 ratio (P less than 0.025). This preferential transmission was discovered through the use of molecular information. Further analysis revealed that this distortion was due to preferential inheritance among children of male carriers (18:4, P less than 0.005). No difference from a 1:1 segregation ratio could be detected among the children of female carriers (7:5). These findings were consistent with a review of relevant data in the literature.

Alleles↗
PubMed1992

[Retinoma and phtisis bulbi: benign expression of retinoblastoma].

Systematic investigation of families of children suffering from retinoblastoma reveals more and more cases of retinoma or phthisis bulbi, cases which used to be called "spontaneous regression". Between 1975 and 1991, we have in this way discovered 11 cases (7%) certain to be carrying retinoma or phthisis bulbi, and a further 5 cases where the same diagnosis is highly probable. Of the 11 certain cases, 5 are unilateral, 6 bilateral, and 8 present family history of the disease. Of the total number of 17 eyes, 16 present retinoma, 1 phthisis bulbi. On clinical examination, all (100%) showed characteristic lesions in the form of greyish homogenous elevated masses in the vitreous cavity. 11 presented calcifications (69%) and in 14 disturbance of the pigment epithelium occurred (87%). The average follow-up is 4 years. Of the 11 patients, 8 are of procreating age and have up to now 25 offsprings. Amongst these, 15 have retinoblastoma (60%), 2 retinoma and phthisis bulbi (8%). All except one of the retinoblastoma cases are bilateral. This study would appear to show that retinoma occurs with a higher frequency than that which is usually given. The figures show clearly that retinoblastoma and retinoma derive from the same genetic disturbances, possibly at different times during cell maturation, and consequently require the same investigation and follow-up.

Adult↗
PubMed1991

[Complications of cataract surgery. Retrospective study of 1,304 cases].

This retrospective study concerns complications arising from 1304 first operations for cataract carried out between 1982 and 1987 by two surgeons having followed the same training and using the same techniques. Loss of vitreous (2.5%) cystoid macular edema (1.9%), and retinal detachement (1.1%) are those complications occurring most frequently in this series. Other serious complications, in descending order, are trauma (0.7%), iris prolaps (0.5%), corneal dystrophy (0.4%), pupillary block (0.3%), expulsive hemorrhage (0.15%), loss of the nucleus in the vitreous (0.07%), panophthalmia (0.07%). Secondary cataract was noted in 31% of cases.

Adult↗
PubMed1991

[Astigmatism in cataract surgery. Retrospective study of 1,304 cases].

We performed a retrospective computerized study of 1304 consecutive cataract extractions, of which 251 were intracapsular and 1053 extracapsular. The analysis of surgically induced astigmatism after a mean follow-up of 22.8 months involved 639 cases. Operations were performed by two experienced surgeons using a similar and standardized technique; however the location of the incision varied without selecting patients: 391 were corneal, 248 limbal. We found that corneal incision gives significantly more against-the-rule astigmatism (average -0.61 dptr) than limbal incision (average -0.32 dptr). The suture induced astigmatism has no determining effect on the final astigmatism (correlation coefficient = 0.011). Selective suture cutting is an interesting technique for an individual dosage of the amount of final astigmatism.

Astigmatism↗
PubMed1991

[Lausanne study of retinoblastoma, 1986-90: deletion of esterase D locus in a collective of 128 patients].

Activity and phenotype of red blood cell esterase D were systematically determined in a population of 128 retinoblastoma patients from 99 families and compared to 158 controls, in order to detect a chromosome 13q14 deletion. Among these patients 12 were healthy carriers and 116 affected carriers of a mutant allele of the retinoblastoma susceptibility gene (110 retinoblastoma, 5 retinoma, 1 phtisis bulbi). 4 patients were found to have decreased ESD levels in connection with 13q14 deletion which was confirmed by chromosome analysis. The data presented here suggest that ESD quantification has a high specificity and sensitivity for the detection of homogenous chromosome 13 deletions in retinoblastoma patients.

Carboxylesterase↗
PubMed1991

Retinoma. Case studies.

The new concept of retinoma, or retinocytoma, brings up the rare 'spontaneous regressions' long-reported in the literature. Systematic investigation of all relatives of children suffering from retinoblastoma is showing up more and more retinoma cases undetected until now. From 1975 to 1990 the authors have identified 11 retinoma cases amongst 103 retinoblastoma patients and their families. The average age of the retinoma patients is 23 years with a mean follow-up of four years. There are four bilateral cases, one of which with phthisis bulbi, three unilateral retinomas associated with retinoblastoma of the fellow-enucleated eye, and four unilateral cases. Of the 11 retinomas, seven patients have a family history of retinoblastoma. Of the seven patients of procreating age, 16 offspring, three abortions and two miscarriages are noted. Of the 16 offspring, 12 developed retinoblastoma, 11 of which bilaterally. One 21-year-old patient presented in the process of malignant transformation. A child, enucleated for retinoblastoma of one eye and showing lesions conforming to retinoma in the fellow eye at two years of age, suffered an osteosarcoma when nine years old. The authors' data show that retinoblastoma and retinoma follow the same genetic changes and consequently require the same investigation and follow-up. This study indicates a frequency of retinoma of 10% amongst retinoblastoma patients and their families which is higher than that usually quoted.

Adult↗
PubMed1990

[Treatment of retinoblastoma and results. Lausanne 1963-1989].

97 cases of retinoblastoma were studied with particular attention to methods of treatment and results. The series includes 41 unilateral cases (42%) and 56 bilateral cases (58%), giving a total of 153 eyes. Of these, 19 (20%) were familial cases. Immediate enucleation was necessary in 88 of the 153 eyes; 61 eyes received conservative treatment; 4 eyes, including one bilateral case, showed spontaneous recovery (retinomas). Conservative treatment consisted of high-voltage external beam irradiation in 43 cases, cryo or photocoagulation in 12 cases, and radioactive applicators in 6 cases. The mortality-rate in cases with over 2-years follow up is of 11%. In 65% of treated cases the eye was saved, with 87% of these retaining useful or central vision. The most serious complications are radiation retinopathy (19%), cataract (16%) and exsudative retinal detachment (9%).

Brachytherapy↗