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Biomedical subjects

A Viestenz

Publications and source records attributed to A Viestenz.

35 records · Page 2Linked to original sources
PubMed2002

[Eye contusions caused by a bottle cap. A retrospective study based on the Erlangen Ocular Contusion Register (EOCR)].

BACKGROUND: Perforating ocular injuries due to exploding beverage bottles are well known. However, bottle caps alone may also induce severe ocular damage due to ocular contusions while opening carbon dioxide-containing beverage bottles. We studied this type of ocular contusion. PATIENTS AND METHODS: Retrospectively, we examined all findings, operations, and tension profiles of 400 consecutive patients with ocular contusion who had been hospitalized in the Department of Ophthalmology, University Erlangen-Nürnberg, using the Erlangen ocular contusion registry (EOCR). RESULTS: Seven patients were injured by bottle caps (1.8%) while attempting to open a beverage bottle. The bottle caps were screw caps in six patients and crown corks in one patient. The patient age was 34 +/- 22 years (range: 16-68 years). Four patients were female, three male. We found the following morphological changes: hyphema (seven patients), iridodialysis (two patients), traumatic cataract (two patients), vitreous prolapse (one patient), vitreous hemorrhage (two patients), and retinal detachment (two patients). Intraocular pressure was higher than 21 mmHg in three patients. Visual acuity was hand motion in two patients, lower then 0.4 in two, and 1.0 in three on the admission day. Five patients read 1.0 on the day of discharge. CONCLUSIONS: Bottle cap injuries are not as harmless as supposed. Bottle caps may induce severe ocular damage due to the high-impact energy.

Adolescent↗
PubMed2001

[Early childhood cataract in hereditary UDP-galactose-4-epimerase deficiency--a case report].

BACKGROUND: Increased plasma galactitol levels may lead to development of bilateral pediatric cataract. PATIENT: A 3-year-old boy was found to suffer from a bilateral zonular cataract. Extracapsular lensectomy with posterior capsulotomy, transpupillar anterior vitrectomy and posterior chamber lens implantation were performed during a 4-month-interval. RESULTS: The epimerase-activity in red cells of the index patient was found to be significantly decreased (11.2 mumol/h/g Hb; normal range; 19-35). From other family members, such as the brother (16.8), the father (16.0) and the grandfather (15.6), a diminished red cell activity was observed. The mother whose epimerase activity was considerably lower than that of the above mentioned family members (13.3) showed also a zonular bilateral cataract. CONCLUSIONS: Investigation of enzymes and polyols of galactose metabolism as well as consultation of the concerned families are recommended for clarification of cataract development.

Cataract↗
PubMed2001

[Wavelet representation of corneal topography data after nonmechanical penetrating keratoplasty--a clinical study].

BACKGROUND: Corneal surface irregularities may limit the visual outcome after penetrating keratoplasty (PK). Corneal topographers mainly render empirically derived and system-specific statistical indices for characterization of superficial inhomogeneities which may lack clinical evidence and make inter-system comparisons difficult. The purpose of this study was to detect and quantify focal surface irregularities of the cornea after nonmechanical PK by 2-dimensional wavelet decomposition based on corneal topography data. PATIENTS AND METHODS: Our study included 15 patients with keratoconus and 10 patients with Fuchs' dystrophy with all-sutures-out after penetrating keratoplasty. For trephination we used the excimer laser MEL60 (Aesculap-Meditec, Germany) (7.5/7.6 mm diameter in dystrophies, 8.0/8.1 mm in keratoconus, double-running 10-0 nylon suture). After suture removal a complete ophthalmological examination including OrbScan topography analysis (Orbtec, USA) was performed. The refraction data were extracted via "data recorder" and decomposed using 2-dimensional wavelet analysis methods (Daubechies-4-wavelets on five scales of resolution). Corneal irregularities were quantified (scale 1 = fine details to scale 5 = coarse details). RESULTS: All detail coefficients (horizontal, vertical and diagonal) correlated statistically significant with the "Irregular Astigmatism" provided by the OrbScan-system (p < 0.05). In scale 3 and 4 a relative maximum of the wavelet detail coefficients occurred, whereas the coefficients at scale 2 and 5 were significantly smaller. The horizontal and vertical detail coefficients correlated significantly inversely with the best-corrected visual acuity (p < 0.04). All detail coefficients were significantly lower in the patient group with keratoconus compared to Fuchs' dystrophy. CONCLUSIONS: Wavelet decomposition of corneal topography refraction data allows an analytical isolation and quantification of focal corneal superficial irregularities. This algorithm is independent of the currently used topography system and allows a smoothing of the raw data set adapted to scale of resolution and data compression.

Adult↗
PubMed2001

[Effect of pupil size on longitudinal focal distribution after photorefractive keratectomy ].

BACKGROUND: Optical aberrations induced by the transition zone of a myopic photorefractive keratectomy (PRK) may degrade the image quality. The subjectively evaluated visual acuity and contrast sensitivity may be reduced significantly especially with mydriasis. The purpose of this study was to calculate the image forming properties of the eye using raytracing techniques of a spot light source based on topographic height data of a scanning slit videokeratoscope. METHODS: Refractive surfaces were calculated from raw height data sets of the anterior and posterior corneal surface measurements (Orbscan, Orbtec, USA). The characteristics of the residual refractive surfaces were derived from Navarro's eye model. The focal distance was calculated using the exact raytracing calculation. Point spread function was determined at the focal plane and at 5 (delta = 0.2 mm) parafocal planes in front of and behind the focal distance in accordance to the pupil diameter (2, 3 and 6 mm). The algorithm was applied to 11 selected eyes (6 left, 5 right) of 8 patients before and after PRK with myopia (n = 6) and myopic astigmatism (n = 5). RESULTS: Before PRK the focal distance did not decrease significantly with increasing pupil size (2 to 6 mm), but decreased significantly after PRK (-0.41 +/- 0.12 mm, p = 0.02). Preoperatively, the variance of the point spread function did not differ significantly between a 2 mm (0.046 +/- 0.015 mm) and a 6 mm (0.055 +/- 0.021 mm) pupil size but was affected significantly by the pupil size postoperatively (2 mm: 0.049 +/- 0.018 mm, 6 mm: 0.096 +/- 0.045 mm, p = 0.04). CONCLUSIONS: Raytracing of corneal topography height data based on refined eye models with the option of calculation of the focus has the potential of tracing the optical resolution of the eye as a function of the pupil size. Due to of the altered surface geometry of the cornea after myopic PRK, both the variance of the point-spread function and the depth of focus increase with pupil size. This may be an explanation for impaired subjective refractometry and reduced contrast sensitivity of the patient after conventional keratorefractive surgery.

Adult↗
PubMed2001

[Conjunctival cyst: subconjunctival luxation of the lens following ocular contusion - a case report].

PATIENT: Presentation of a 75-year-old female with subconjunctival lens luxation, that was initially misdiagnosed as conjunctival cyst. Initial examination had been difficult due to vascularized stromal corneal scars and a large hyphema. The ocular history revealed an ocular contusion 11 months ago. Aphakia with subconjunctival lens luxation, iris incarceration, iridodialysis and covered scleral rupture were diagnosed by inspection, palpation, slit-lamp biomicroscopy, gonioscopy and ultrasound biomicroscopy. The lens and incarcerated iris tissue were removed, the scleral wound was sutured and a penetrating keratoplasty was performed in combination with anterior vitrectomy and implantation of a transclerally sutured posterior chamber lens. The histologic investigation of the subconjunctival tissue showed the complete lens with intact lens capsule and surrounding subconjunctival connective tissue. CONCLUSION: Hyphemas following ocular contusion are frequent findings. A large hyphema may masquerade alterations of other ocular structures. The differential diagnosis of posttraumatic prominent conjunctival "tumors" should include subconjunctival luxation of the lens.

Aged↗
PubMed2001

[Retrospective analysis of 417 cases of contusion and rupture of the globe with frequent avoidable causes of trauma: the Erlangen Ocular Contusion-Registry (EOCR) 1985 - 1995].

BACKGROUND: Ocular trauma is the cause of every third enucleation. Blunt injuries belong to the most frequent causes. We analysed blunt ocular injuries to collect detailed epidemiological data. PATIENTS AND METHODS: Retrospective analysis of 417 inpatients of the university-eye-hospital Erlangen from 1985-1995 with ocular contusion or globe rupture (EOCR - Erlangen Ocular Contusion-Registry). RESULTS: One third of the injuries occurred during work time, more than 40 % during leisure time. 85 % of the patients were male. One half was 10 to 29 years old. Visual impairment of less than 20/200 was more frequently associated with severe damage of intraocular structures: 53 times more ruptures of the globe, 33 times more lens luxation, 17 times more retinal detachment. Visual acuity was lower following traumas due to fall and grinding. Visual impairment was rarely induced by large objects like soccer balls. Morphological findings included: hyphema (73 %), rebleeding (4 %), angle recession (71 %), iris sphincter tears (20 %), iridodialysis (10 %), cyclodialysis (3,4 %), traumatic aniridia (1 %), lens dislocation (15 %), traumatic cataract (10 %), choroidal rupture (7 %), retinal tear or detachment (7 %), Berlin's edema (35,5 %), globe rupture (4,6 %), blow-out-fracture (8,3 %). Vitreal prolapse (7,5 %) was often associated with vitreal hemorrhage (57 %), hyphema (86 %), globe rupture (20 %), iris sphincter tear (44 %), iridodialysis or cyclodialysis (43 %), traumatic cataract (41 %), lens dislocation (93 %) and retinal tear or detachment (29 %). CONCLUSIONS: Blunt ocular injuries frequently induce severe ocular damage. Only consequent attention to industrial safety act, general preference given to rounded edges and the urgent information about safety eyeware for hobbyists may reduce the number of ocular injuries with permanent morphological and functional damage.

Accidental Falls↗
PubMed2000

Correlation among refractive, keratometric and topographic astigmatism after myopic photorefractive keratectomy.

BACKGROUND: Photorefrative keratectomy can be used to flatten the curvature of the anterior cornea and reduce the myopic refraction of the eye. This leads to unphysiological topographical changes of the cornea and may alter the conditions for examinations of corneal surface topography. The purpose of this study was to check for mutual agreement of three different methods of assessment of astigmatism before and after myopic photorefractive keratectomy (PRK). PATIENTS AND METHODS: Forty-seven eyes of 28 patients (age 32.7+/-6.6 years) following PRK using an 193-nm excimer laser were included in this study. 37 eyes were treated for pure myopia (-4.9+/-2.4 D) and 10 eyes for myopic astigmatism (sphere -2.0 to -7.0 D, cylinder -1.0 to -3.0 D). Preoperatively and at 18 months postoperatively, subjective refractometry, keratometry and topography analysis were performed. The axes of topographic and keratometric cylinder were standardized periodically (180 degrees) with respect to the refractive cylinder axis. RESULTS: Pre- and postoperatively, the absolute astigmatism values correlated highly significantly between all three methods (P< or =0.001). The mean refractive cylinder was 0.65+/-0.61 D preoperatively and 0.46+/-0.41 D postoperatively (P=0.2). The mean keratometric astigmatism was 1.14+/-0.64 D before and 0.94+/-0.50 D after PRK treatment (P=0.2). Among the three methods, the mean topographic astigmatism was the highest (P<0.001) preoperatively (1.31+/-0.56 D) and postoperatively (1.21+/-0.52 D) (P=0.3). In eyes treated for pure myopia, no difference between pre- and postoperative refractive, keratometric and topographic astigmatism was detected (P>0.5). The axes of both topographic and keratometric astigmatism correlated highly significantly with the refractive cylinder axis (R> or =30.9, P<0.0001). CONCLUSION: Up to 2 years after myopic PRK, the difference between refractive and keratometric astigmatism does not differ from the preoperative value, indicating an even corneal surface. The absolute astigmatism values and the cylinder axis correlated well between subjective and objective methods of astigmatism assessment. Thus, objective measurements may be helpful in determining the cylinder component of best spectacle correction after PRK. However, topographic analysis overestimates astigmatism values systematically before and after PRK.

Adult↗
PubMed2000

Anterior chamber depth and complications during cataract surgery in eyes with pseudoexfoliation syndrome.

PURPOSE: To look for associations of preoperative A-scan ultrasound ocular dimensions with complications during phacoemulsification in eyes with pseudoexfoliation. METHODS: A total of 174 eyes with pseudoexfoliation of 135 patients undergoing planned cataract surgery were included in a prognostic study based on the review of a clinical database. Preoperatively, A-scan ultrasound examination with measurement of anterior chamber depth, lens thickness, and total axial length was performed. Phacoemulsification with implantation of a posterior chamber intraocular lens was performed by a total of five surgeons. Intraoperative complications (zonular dialysis and/or vitreous loss) were correlated with preoperative findings including ultrasound dimensions. Multivariate logistic regression analysis with a generalized estimating equations method was used for statistical analysis. RESULTS: Intraoperative complications occurred in 12 eyes (6.9%) of 11 patients. The anterior chamber was significantly shallower in eyes with than in eyes without complications (mean, 2.36 +/- 0.44 mm vs 2.74 +/- 0.52 mm; P =.013). The differences in lens thickness (4.93 +/- 0.55 mm vs 4.72 +/- 0.54 mm; P =.30) and the differences in axial length (22.92 +/- 1.09 mm vs 23.66 +/- 1.36 mm; P =.07) between the two groups did not reach statistical significance. In eyes with pseudoexfoliation, an anterior chamber depth of less than 2.5 mm was associated with a risk of 13.4% for intraoperative complications compared with an overall incidence of intraoperative complications of 6.9% and an incidence of 2.8% for an anterior chamber depth of 2.5 mm or more. CONCLUSIONS: A small anterior chamber depth may indicate zonular instability in eyes with pseudoexfoliation syndrome and should alert the cataract surgeon to the possibility of intraoperative complications.

Aged↗
PubMed2000

[Eyelid tumor as a recurrence of a gastric MALT-lymphoma].

BACKGROUND: MALT Lymphoma of the conjunctiva, eyelid and orbit represents a primary manifestation of the disease in most of the cases. CASE REPORT: A 58-year-old male presented with a tumor in the left inferior eyelid. A full-thickness incisional biopsy was performed. Histopathologically, a lymphoid infiltrate involved the eyelid in its full width, with reactive follicles surrounded by small cells with irregular nucleus. Follicular colonization and lymphoepithelial lesions were detected. The tumor was CD20 positive. The molecular genetic analysis disclosed a monoclonal B-cell proliferation. The patient had a history of gastric MALT lymphoma treated 9 years ago and he had been otherwise in good health. The histopathologic features of the gastric tumor were identical to those of the eyelid lesion. Since the eyelid tumor represented a recurrence of the disease, treatment consisted of systemic chemotherapy. Complete tumor eradication was obtained. CONCLUSION: Ocular adnexal MALT-lymphomas may represent a recurrence of a distant primary MALT-lymphoma after a long disease-free period and, therefore, be an indication for systemic chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Outpatient management of traumatic hyphemas in children.

OBJECTIVE: There are no outcome reports in the literature for outpatient management of traumatic hyphemas in children. Therefore we studied such cases at our institutions. DESIGN: Retrospective chart review. PARTICIPANTS: 25 children less than 16 years of age with grade I traumatic hyphemas. INTERVENTION: Inactivity at home with frequent office visits to monitor progress and complications. Treatment otherwise varied but virtually all patients received protective eye shields and topical steroids. MAIN OUTCOME MEASURES: Rate of rebleeding and final visual acuity. RESULTS: Three patients (12%) suffered a rebleed; one required surgery for clot evacuation. One of the three did not receive topical steroids and if he is excluded, rebleed rate is 2/24 or 8.3%. The hyphema resolved without sequelae in the other 22 patients. All patients had a final visual acuity of 20/40 or better except three patients (12%) who had concurrent vision-limiting ocular injuries and/or disease. Final visual acuity was 20/30 or better in all three patients with rebleeds. CONCLUSIONS: Our rebleed rate was within the broad range of rebleed rates reported in the literature. However, improved efforts to identify children at highest risk for rebleeding, to maximize compliance with treatments, and to consider systemic agents in selected cases, could further reduce the rebleed rate and increase acceptance and safety of outpatient management in pediatric traumatic hyphemas.

Adolescent↗