Biomedical subjects

K Mittelviefhaus

Publications and source records attributed to K Mittelviefhaus.

6 recordsLinked to original sources

PubMed2002

[Astigmatism after trans-scleral posterior chamber lens implantation in young children].

BACKGROUND: The purpose of this study was to evaluate the postoperative astigmatism after trans-scleral fixation of intraocular lenses in children and to develop a strategy for amblyopia prophylaxis. PATIENTS AND METHODS: In eight eyes with lentectomy, posterior chamber intraocular lenses were fixed in the ciliary sulcus by trans-scleral sutures. The postoperative astigmatism was measured by retinoscopy every 1 to 2 weeks in the first 2 months, followed by monthly intervals thereafter. Keratometry was performed with an automated hand keratometer. RESULTS: Postoperative astigmatism was 2.5 to 8.0 D. The astigmatism regressed to 0.75 D in half the eyes within 4 weeks and in five of the eyes within 16 weeks. In one of the eight eyes, the astigmatism decreased to 2.0 D and in two it remained unchanged. The astigmatism did not change any more after 16 weeks postoperatively. Visual acuity was 0.016 to 1.0. CONCLUSIONS: Our study shows that the postoperative astigmatism regresses soon and does not seriously interfere with amblyopia therapy. If greater than 2 D, half of the astigmatism should be corrected with glasses, even in the early postoperative period. After 16 weeks, full correction is recommended.

Amblyopia↗

PubMed2001

Segregation patterns and heteroplasmy prevalence in Leber's hereditary optic neuropathy.

PURPOSE: To investigate the segregation pattern of the mitochondrial DNA mutation at nucleotide position 3460 responsible for Leber's hereditary optic neuropathy (LHON) and to determine the prevalence of heteroplasmy for the three primary LHON mutations at positions 11778, 3460, and 14484. METHODS: Segregation analysis was performed in a cross-sectional study by determining the level of heteroplasmy in blood leukocytes of 23 LHON patients and unaffected carriers from four unrelated families. One family comprising two affected and three unaffected carriers was followed over 5.5 years for a longitudinal segregation analysis of heteroplasmy. The percentage of mutant mtDNA was determined using a novel procedure of fluorescence-based primer extension and restriction fragment length polymorphism analysis. The prevalence of heteroplasmy was assessed by determining the number of genealogically unrelated LHON pedigrees with heteroplasmic maternal family members from the LHON patient records of the Department of Ophthalmology, University of Tübingen, Germany. RESULTS: The authors observed a marked variability in the degree of heteroplasmy levels within each pedigree and a tendency toward a higher mutant allele frequency in offspring generations. Disease expression was correlated with higher levels of mutant mtDNA molecules. Longitudinal analysis revealed no statistically significant decrease in the heteroplasmy level in the family studied but a reduction of 11% and 12% in one affected and one unaffected individual, respectively. In 167 genealogically unrelated LHON families the prevalence of heteroplasmy was 5.6%, 40%, and 36.4% for the 11778, 3460, and 14484 LHON mutations, respectively. CONCLUSIONS: Cross-sectional studies of heteroplasmy for the 3460 LHON mutation suggest that the genotype shifts toward a higher mutational load in offspring generations. Long-term decrease in the blood mutant load in single cases indicates negative selection of the mutant allele in the hematopoietic cell system. The prevalence of heteroplasmy varies significantly between the different primary LHON mutations, suggesting genotypical differences in disease expression.

Chromosome Segregation↗

PubMed2000

Transscleral suture fixation of posterior chamber intraocular lenses in children under 3 years.

BACKGROUND: Children who have undergone lentectomy for congenital or traumatic cataract do not have adequate capsular support for secondary posterior chamber intraocular lens (PC-IOL) implantation and thus will become severely amblyopic if contact lens intolerance occurs. In order to prevent amblyopia we fixed PC-IOLs by transscleral sutures in three children younger than 3 years. Clinical outcome, visual acuity and course of refraction were studied. METHODS: Four eyes of three children with contact lens intolerance were operated. Posterior chamber lenses (PC-IOL) were sutured in the ciliary sulcus by transscleral sutures. Two children had monocular traumatic cataract and one child underwent surgery on both eyes for congenital cataract. To allow adjustment of refraction in situ without removing the primarily implanted and transsclerally fixed PC-IOL we used the piggyback intraocular lens system for implantation. RESULTS: Visual acuity improved in all four eyes. The two children with traumatic cataract achieved visual acuity of 0.7 and 1.0, respectively, and stereopsis. No complications related to the technique of transscleral suture fixation of the PC-IOL were observed. Postoperative changes in refractive power were caused by a myopic shift between -1.0 D and -9.0 D. Follow-up was 25-70 months. CONCLUSION: Transscleral suture fixation of PC-IOLs did not cause specific complications during follow-up of up to 70 months. This technique offers an important option for the correction of an aphakic refractive error which cannot be corrected otherwise. In future the piggyback intraocular lens system may help to rather atraumatically correct postoperative changes in refractive power.

Cataract↗

PubMed1998

[Etiology of contact lens failure in pediatric aphakia. Indications for intraocular lenses?].

UNLABELLED: Due to the low rate of complications, lentectomy and contact lens fitting is the standard treatment for congenital cataract. However, contact lens fitting is not possible in all children. The authors report the main reasons for discontinuation of contact lenses in their patients. METHOD: In 134 consecutive lentectomies of 90 children, the underlying eye diseases and general diseases, the age at operation, compliance of parents and children, and social background were analyzed. RESULTS: Twenty of the 90 children had to discontinue contact lens wearing. Twelve of these children were operated on one eye and 8 on both eyes. Only 2 children showed signs of contact lens complications. In 2 children treatment was stopped because of the poor visual prognosis and in 10 children the parents discontinued contact lens treatment because of a severe handicap of the child (n = 2) or due to misunderstanding and parental noncompliance (n = 8). Six children refused contact lenses without obvious reasons. Among the latter, children 2-4 years of age were at the greatest risk. Children with additional systemic abnormalities frequently developed contact lens intolerance. CONCLUSION: In children with systemic abnormalities and in the case of parental communication and compliance problems, discontinuation of contact lenses has to be expected in up to 30% of cases. In these children and in children who object to contact lenses at the age of 2-4 years, intraocular lens implantation should be considered, especially in unilateral cataract, if successful contact lens treatment is not achievable within 8-12 weeks.

Aphakia, Postcataract↗

PubMed1997

[Retinal hemorrhage in the infant as an indication of shaken baby trauma].

BACKGROUND: The shaken baby syndrome is a form of child abuse in young children. Typical are intracranial and intraocular bleedings. As external injuries are often missing, the shaken baby syndrome may easily be overlooked. Intraocular bleeding is a major diagnostic sign and can prove the diagnosis, if child abuse is suspected by the paediatrician. Thus critical family situations can be uncovered and long term help can be initiated. PATIENTS: Between 1991 and 1997 seven babies (age two to nine months) with intraocular bleedings were examined. Diagnosis, differential diagnosis and prognosis of the shaken baby syndrome are presented with these children. RESULTS: In two of the seven children a non-accidental trauma and shaken baby syndrome was obvious. In three cases the diagnosis of a shaken baby syndrome was most probable. In one child intraocular bleeding was possibly caused by a fall three months earlier. One child had retinal bleedings after resuscitation. In two cases a vitrectomy was performed. The follow up was two months to six years. In two children intraocular bleeding resolved completely, three children developed mild to severe amblyopia and two children became blind. Vitrectomy could not prevent loss of sight. CONCLUSIONS: Sudden cerebral symptoms or intraocular bleedings in otherwise healthy young children are suspicious for child abuse. A shaken baby syndrome has to be considered. Thus funduscopic examination in mydriasis is obligatory. The prognosis depends on the severeness of ocular hemorrhages and cerebral lesions.

Battered Child Syndrome↗

PubMed1993

[The Freiburg Vision Test. A computer-assisted procedure with sequential strategy].

Single Landolt Cs were presented in one of four positions on a monitor. Subjects responded by pressing one of four buttons (forced choice). A computer selected the size of the Landolt Cs on a logarithmic scale using the "Best PEST" algorithm (Best Parameter Estimation by Sequential Testing), a modern procedure to measure psychophysical thresholds. For comparison, conventional measurements according to DIN 58220 (Deutsche Industrie Norm) were performed with Landolt Cs projected in eight positions, using three out of five correct responses as the threshold criterion. Examination of 23 patients (most of them with senile cataract) did not show any significant difference between the two tests in either visual acuity or reproducibility on two consecutive days. The coefficients of variation between sessions were 22% for the Freiburg test and 26% for the DIN test and 18% between the two tests, pooled over two sessions. The Freiburg acuity test thus appears to be numerically equivalent to the DIN 58220 procedure. In addition, it has a number of advantages: (1) examiner-dependent variability is reduced; therefore, the test can be used by inexperienced examiners; (2) the forced choice technique is used rigorously; (3) mistakes in confounding oblique directions are largely avoided; (4) the procedure is about twice as fast.

Adult↗