Biomedical subjects

B Wiechens

Publications and source records attributed to B Wiechens.

25 records · Page 2Linked to original sources

PubMed1996

[Butterfly-shaped dystrophy of the macula].

BACKGROUND: The butterfly-shaped dystrophy of the macula is an extremely rare autosomal dominant retinal disorder first described by Deutman in 1970. Two cases are presented. CASE REPORTS: The first patient presented to the clinic with slight deterioration of vision OD. Corrected visual acuity was OD 0.63 and OS 0.8. Examination of anterior segments was normal bilaterally. Funduscopically there was a mild disturbance of the foveolar retinal pigment epithelium. Fluorescein angiography, however, disclosed a large pattern-like hypofluorescence with hyperfluorescent areas in the macular region. Visual fields and electroretinography were normal. The second patient complained of decreased visual acuity OU. Funduscopic and angiographic findings were similar to the first patient. CONCLUSION: Different forms of pattern dystrophies of the macula have been described in the literature with moderate visual impairment. Differentiation is sometimes difficult as some forms have been reported to occur in one family. They may represent different clinical entities of the same disease. Diagnosis is usually made by fluorescein angiography.

Chromosome Aberrations↗

PubMed1993

[Excentric lentiglobus posterior].

BACKGROUND: The posterior lentiglobe is a rare anomaly of the lens shape. Two cases of excentric protuberance of the posterior capsule are presented. To our knowledge, only one description of a similar case exists so far. PATIENTS: An eight-year-old girl (diagnosis by routine examination, V.A. 20/20) and a six-year-old boy (V. A. 20/200, esotropia) are presented. Apart from a persistent hyperplastic primary vitreous and a posterior pole cataract a vitreous cyst adherent to the posterior surface of the lens has to be considered as differential diagnosis. The etiology remains unclear. CONCLUSION: In excentric posterior lengtiglobe a good vision is possible. However, if visual acuity is impaired by posterior pole opacity or distortion of the spherical surface, removal of the lens followed by optical correction (contact lens, intraocular lens) of aphakia should be performed.

Cataract Extraction↗

PubMed1991

[A convex-concave contact lens for vitreoretinal operations with the BIOM].

A new convex-concave contact lens for wide-angle vitreoretinal surgery with the BIOM was developed. Placed on an eye, in which silicone oil is injected, it prevents the formation of an optically disturbing oil-water-film on the surface of the cornea. Thus the new contact lens leads to an essential improvement of the fundus view intraoperatively without affecting the optical properties of the BIOM.

Contact Lenses↗

PubMed1991

[Visual changes after silicone oil injection].

Patients frequently complain of visual changes after intraocular silicone oil injection. The degree of these changes as well as refractive changes were analyzed in 11 aphacic eyes that had a postoperative visual acuity of at least 0.1. Visual acuity and refraction were obtained with the patients in a supine position. Then multiple visual acuity tests were done and refraktion was measured up to 12 times a day with the patient sitting erect. All tests were done with a constant pupillary diameter. Mean differences of 3 D between the objective and subjective refraction were noted. In most eyes there was a shift of spherical equivalents towards hypermetropia after a change in posture from supine to erect. The mean shift was 3.4 D (range 0.75-6.25 D). Seven out of 11 patients showed an increase in visual acuity of up to 4 optotypelines within the first 4 h after changing to an erect position. Total eye examination and testing of best-corrected visual acuity were performed again between 4 weeks and 15 months after silicone oil removal (mean 9.6 months). On examination, all eyes had a totally attached retina; none developed secondary glaucoma. Ten out of 11 eyes did not attain a final visual acuity that was better than the best corrected visual acuity before silicone oil removal.

Diabetic Retinopathy↗

PubMed1990

[Occlusive retinal vasculopathy with subsequent secondary glaucoma. Demonstration of typical findings and therapeutic references].

The etiology of occlusive vascular retinopathy with subsequent neovascular glaucoma has not been clarified even today. If not diagnosed in the early stage therapy is often unsuccessful. Men and women aged between 35 and 65 years are affected with equal frequency. In a group of nine patients presenting at our clinic within three years four had irreversible functional loss by the time of the initial examination. In eyes with better visual function at the time of diagnosis only minimal vision and visual field can be preserved. Even this is only possible with intensive therapeutic efforts. Besides a rapid diagnosis to exclude prior vascular processes that can be treated areas of the retina with reduced perfusion always need to be treated by means of cryo- or lasercoagulation. Adjacently inhibitors of thrombocyte-aggregation to improve perfusion should be administered. Any delay of coagulation should be avoided since resulting secondary glaucoma is very difficult to treat.

Adult↗

PubMedDate not supplied

Retinal toxicity of liposome-incorporated and free ofloxacin after intravitreal injection in rabbit eyes.

BACKGROUND: Ofloxacin (OFLX) is a fluoroquinolone-antibiotic with a broad antimicrobial spectrum that may have a potential role in the treatment of bacterial endophthalmitis. However, its elimination half life after intravitreal injection is short. To prolong the intravitreal antibacterial level OFLX was incorporated into liposomes. This study was performed to investigate the retinal toxicity of liposome-incorporated and free OFLX. MATERIALS AND METHODS: OFLX was incorporated into multilamellar large vesicles. 0.1 ml of this suspension (= 180.2 microg OFLX) was injected into the midvitreous of rabbit eyes (n = 6). Free OFLX in doses of 100 microg, 500 microg and 1,000 microg was injected into the midvitreous of a second group of rabbit eyes (n = 18). The other eye served as a control and received empty liposomes or normal saline solution, respectively. Before injection and at the end of follow-up an ERG was obtained. After a follow-up of 1 day, 14 and 28 days the animals were perfused with glutaraldehyde and the eyes were examined by light- and transmission electron microscopy. RESULTS: The ERG as well as the histologic studies did not reveal any pathological changes after injection of liposome-incorporated OFLX compared to the control eyes. Significant reduction of the ERG was observed after 500 microg free OFLX in 2 out of 6 eyes after 1 and 14 days, respectively, and in 2 eyes 1 day after 1,000 microg free OFLX. Three days after injection of 1,000 microg OFLX the retina showed focal destruction in 1 out of 6 eyes. In another eye with the same dose 14 days after injection the photoreceptor outer segments showed disorganisation. CONCLUSION: This study shows that liposome-incorporated OFLX did not have any retinal toxicity in this animal model. Free OFLX appears to have no retinal toxicity in rabbit eyes at a dose of 100 microg after intravitreal injection. Injection of higher doses resulted in ERG changes and marked retinal damage.

Animals↗

PubMedDate not supplied

Bilateral cataract after phakic posterior chamber top hat-style silicone intraocular lens.

BACKGROUND: New strategies have been developed for surgical treatment of high myopia. Recently, implantation of minus power posterior chamber intraocular lenses (IOL) into phakic eyes has been introduced. METHODS: We report a 37 year-old female patient who developed bilateral anterior subcapsular cataract 7 years after minus-power, top hat-style silicone posterior chamber IOL implantation in Russia. The corrected visual acuity was right eye 20/200 and left eye 20/63. Because of the high myopia and the posterior chamber IOL in her phakic eyes, biometry for IOL calculation gave contradictory results. Both posterior chamber IOLs were found to be adherent to the crystalline lenses. After posterior chamber IOL explantation and phacoemulsification, intraoperative retinoscopy was performed. With this aphakic refraction, the IOL power was calculated and implanted. The explanted posterior chamber IOLs were examined by scanning electron microscopy. RESULTS: After bilateral operation the corrected visual acuity increased to right eye 20/32 and left eye 20/40, respectively. On scanning electron microscopy, a membranous structure of unknown origin was noted on the entire surface of the explanted posterior chamber IOLS. CONCLUSION: There is a potential risk of cataract formation after implantation of this top hat-style silicone posterior chamber IOL. If cataract extraction in this specific situation is needed, a different approach for calculating the aphakic IOL power is necessary, such as intraoperative retinoscopy.

Adult↗