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Biomedical subjects

O E Schnaudigel

Publications and source records attributed to O E Schnaudigel.

At least 19 recordsLinked to original sources
PubMed1998

[Capsular sack-fixed IOL implantation in pediatric cataract. Visual prognosis and complications].

BACKGROUND: The aim of the study was to evaluate results of visual acuity and binocularity and complications after cataract surgery with primary capsular bag-fixated IOL implantation in children. MATERIALS AND METHODS: Thirty-three children [mean age (+/- SEM) 6.9 +/- 2.9 years, range 3-12 years] accounting for 43 eyes, were examined before and after surgery (15 traumatic, 19 developmental, and 9 congenital cataracts, of the latter two groups 9 unilateral and 19 bilateral cataracts). RESULTS: All eyes had a best corrected postoperative visual acuity of 0.5 +/- 0.05. The postoperative visual acuity of the traumatic cataracts was 0.6 +/- 0.07, of the developmental cataracts 0.5 +/- 0.07, and of the congenital cataracts 0.2 +/- 0.05. Of the 43 eyes, 17 (40%) showed a best corrected visual acuity of 0.5 or better. There was a positive correlation between morphology (lamellar versus subcapsular opacification) and visual acuity (0.7 +/- 0.07 versus 0.5 +/- 0.05; P < 0.05). Bilateral cataracts had a better postoperative visual acuity than unilateral cataracts (0.7 +/- 0.07 versus 0.2 +/- 0.05 P< 0.001) Stereopis was found postoperatively in 62% of the children. In one eye a capsular bag-fixated IOL implantation was not possible, and so the IOL was inserted in the sulcus. Four children presented with postoperative fibrin formation. Posterior capsule opacification occurred in 19% of the eyes in which a primary posterior capsulotomy had been performed. CONCLUSIONS: The prognosis of visual acuity and the results of stereopsis in children older than 3 years following capsular bag-fixated IOL implantation are very good. Both the intraoperative and postoperative complication rates were low.

Cataract↗
PubMed1997

[Pars plana implantation of a ganciclovir drug carrier in patients with cytomegalovirus retinitis and AIDS. Indications, follow-up and postoperative complications].

UNLABELLED: We performed an open clinical trial to assess the safety and efficacy of a 1 microgram/h ganciclovir implant for the treatment of newly and pretreated cytomegalovirus (CMV) retinitis in patients with the acquired immunodeficiency syndrome (AIDS). PATIENTS AND METHODS: Thirty-two eyes (20 patients) received the ganciclovir intraocular device and were prospectively followed up from 30 to 365 days. We used a modified technique for fixation of the device in half of the patients. The modification improved the fixation of the implant with a two-hole technique in the strut. RESULTS: Thirty eyes showed stabilization of the retinitis over the time, but in two patients resistance against ganciclovir and other nucleoside analogue compounds developed. Postoperative complications included vitreous hemorrhage (n = 1), cataract (n = 1), and uveitis anterior (n = 1). Late retinal detachment was seen in five eyes (25%) at 30 to 60 days after implantation. Followup until 1 year after implantation did not show progression of CMV retinitis in 18 to 20 patients. All received antiviral CMV therapy to protect noninfected eyes and intestinum against CMV infection. CONCLUSIONS: The ganciclovir intraocular device seemed to be effective in most cases of CMV retinitis and offers a promising alternative for cytomegalovirus retinitis. Patients pretreated longer than 6 months with i.v. ganciclovir have to be carefully selected for implantation, because resistance against ganciclovir could be three times more likely than in i.v.-therapy naive patients.

AIDS-Related Opportunistic Infections↗
PubMed1996

[Effect of cataracts on contrast pattern reversal stimuli exemplified by the pattern electroretinogram].

A cataract changes pattern-evoked contrast responses to a mostly unknown extent by a blurred retinal image. Pattern electroretinograms (P-ERG), evoked by a reversing checkerboard pattern, were measured (a) in 12 healthy volunteers with a cataract simulated by Bangerter foils; (b) pre- and postoperatively in 44 cataract eyes without retinal damage; and (c) in 13 healthy contralateral eyes. Slight media opacities (visual acuity 1.0 to 0.8) already diminished the amplitudes of the pattern ERG significantly, whereas the latencies did not react significantly. This can be explained by a decrease more in contrast than in luminance. Postoperatively, the amplitudes continued to increase during the first 10 weeks, when the visual acuity remained stable. The postoperative amplitudes did not reach the amplitudes of comparable healthy contralateral eyes. It is recommended that eyes be checked for cataracts before an interpretation is made.

Adolescent↗
PubMed1995

[Prognostic factors in selected stab injuries of the posterior eye segment].

Vitreoretinal proliferation (PVR) is an important cause of severe visual loss in eyes with penetrating injuries. The aim of this work was to study the occurrence of early signs of PVR in eyes with penetrating injuries and no indication for vitrectomy within the first 14 days and to identify the factor that correlates most with high incidence and early onset of PVR. Furthermore, the aggressiveness of PVR in this group of patients was studied. We examined 51 patients (mean age 36 years) with penetrating ocular injuries using indirect ophthalmoscopy and B- and A/B-scan-echography. The mean follow-up interval was 24 months. The factor that correlated most with high incidence and early onset of PVR was a scleral laceration length of > 6 mm. The incidence of PVR was at any time significantly higher in eyes with a scleral laceration length of > 6 mm than in eyes with a scleral laceration length of < 6 mm (P < 0.0313). A negative correlation was shown between the length of the scleral laceration and the time of onset of PVR (r = 0.3441; P = 0.0006). Four eyes (8%) underwent vitrectomy because of aggressive development of PVR. A scleral laceration length of > 6 mm is the most important risk factor for high incidence and early onset of PVR in eyes with penetrating injuries with no indication for vitrectomy within the first 14 days.

Adult↗
PubMed1994

[Viability of corneal endothelium after long-term storage at +4 degrees C in Optisol].

For successful corneal transplantation endothelial cell function of at least 50% is considered necessary. Corneal grafts are often evaluated by morphological criteria, such as endothelial cell size or density. Donor corneas with a storage time longer than 10 days are usually excluded from transplantation. The viability of the endothelium of 35 human donor corneas was evaluated after storage for up to 27 days at +4 degrees C in Optisol storage medium by using the Janus green photometry technique. The results were compared with the endothelial cell density counted. We demonstrated that the human corneal endothelium remains satisfactorily viable (minimum 68% viable cells) for a period of at least 27 days and that morphological changes do not sufficiently reflect the functional intactness of the cornea. Morphological irregularities should be interpreted as a form of compensation by a viable endothelial cell layer.

Aged↗
PubMed1994

[Ophthalmologic manifestations in early and late stages of AIDS].

In a prospective study of 101 patients with HIV infection and a medium CD4 lymphocyte cell count of 350 x 10(6)/l and a retrospective study of the records of 79 AIDS patients, we compared the first ocular symptoms in HIV-infected patients to the CD4 count. In Walter-Reed stages 2-4 (n = 101) we found sicca syndrome in 9.2%, in 52% lens opacities in the cortex and only in less than 1% HIV-related angiopathy of the retina. In Walter Reed stages 5-6 (n = 79), 26% of the AIDS patients developed CMV retinitis, 33% HIV angiopathy of the retina and only 1% retinal toxoplasmosis. The average CD4 lymphocyte cell count was never better than 100 x 10(6). Lens opacities in HIV-infected patients could be an early ophthalmological symptom of HIV infection.

AIDS-Related Opportunistic Infections↗
PubMed1992

[Image quality of various types of intraocular lenses (mono-, bi- and multifocal) in air and water].

Most of the monofocal intraocular lenses tested in air and water showed good-to-high resolution in water. There was low resolution in the outer zone of the image in some models. The bifocals tested had a lower resolution efficency with less contrast and change of colors. The diffractive IOL had poor central resolution efficiency with changing colors and double vision. There was a spherical change like a fish-eye. When tested in air there was paracentral double vision in the diffractive IOL with a change of color bands.

Humans↗
PubMed1991

[Changes in the visual field caused by lens opacities].

60 eyes with advanced opacity of the lens nucleus and a corrected visual acuity of at least 0.1 have been examined by Octopus perimetery before and after a cataract extraction with posterior chamber lens implantation. 20 eyes had chronic glaucoma with glaucomatous alterations of the optic nerve head. Our purpose was to determine the effect of lens opacities on the result of automated perimetry especially in view of glaucomatous field defects. The influence of the cataract on the differential light threshold in the whole field (30 degrees) area showed a wide variance. The calculated visual field indices loss variance (LV) and corrected loss variance (CLV) did not clearly separate glaucomatous from cataractous field changes. Often an exact analysis of the numerical printout of the visual field helps in finding of localized glaucomatous field defects.

Adult↗
PubMed1990

[Anatomy of the ciliary sulcus].

The space between the posterior surface of the base of the iris and the anterior surface of the ciliary body - the ciliary sulcus - and the capsular bag are the sites for a posterior chamber lens implant after extracapsular cataract extraction. In human cadaver eyes and in eyes after cataract extraction, the exact topographical relationship of the ciliary sulcus and the surrounding tissue was analyzed. The anatomical findings and important variations are documented by light microscopy and macrophotography and the relationship to lens implantation is discussed.

Ciliary Body↗
PubMed1989

Comparison of different models for the testing of pilocarpine eyedrops using conventional eyedrops and a novel depot formulation (nanoparticles).

An objective in the development of ophthalmic formulations is the use of in vitro or animal models that closely resemble the clinical situation. For this reason, experiments with conventional pilocarpine nitrate eyedrops and a depot formulation of pilocarpine nitrate sorbed to poly (butylcyanoacrylate) nanoparticles were carried out. In vitro, the diffusion of pilocarpine through bovine cornea was measured using Edelhauser cells. In vivo, the rabbit aqueous humor concentration of pilocarpine and miosis were determined after application of the above formulations. In addition, intraocular pressure was measured. Since pilocarpine has little influence on intraocular pressure in healthy rabbits, the pressure had to be increased artificially. Three models were employed that are described in the literature, namely, the betamethasone model, the alpha-chymotrypsin model, and the water-loading model. Pilocarpine could be loaded onto nanoparticles by 15% but was rapidly released from the nanoparticles based on the bovine corneal experiment. Nanoparticles only enhanced the aqueous humor concentration at 30 min; this increase, however, led to a considerably extended period of miosis as well as a reduction in intraocular pressure. The duration of the action and the intensity of the response were different among the three models tested. According to the present results, the betamethasone model seems to represent the best correlation to the clinical situation.

Animals↗
PubMed1989

[Intraocular ossification].

Following a general introduction to the problem of heterotopic bone formation the pathogenetic stages of intraocular ossification are described. Intraocular ossification was found in 30 (7%) of 423 eyes enucleated between 1974 and 1984. In 60% of the eyes the ossification was associated with trauma, in 25% with chronic uveitis. Bone formation started between four and 44 years after the onset of ocular disease and in most cases originated in the retinal pigment epithelium.

Adolescent↗
PubMed1989

[Evaluating the postoperative depth of the anterior chamber in primary extracapsular cataract extraction and intraocular lens implantation].

To evaluate the depth postoperatively of the anterior chamber, a second biometry by ultrasound was done in 100 eyes 6-12 months after cataract extraction and IOL implantation (sulcus fixation). The aim was to compare the depth of the anterior chamber preoperatively with that measured postoperatively. The measurement showed a middle anterior chamber depth of 3.42 mm preoperatively and 3.67 mm postoperatively. This means that there was a mean increase in the anterior chamber depth of 0.25 mm.

Anterior Chamber↗
PubMed1988

[Carteolol: general practice-oriented assessment of the effectiveness and tolerance of a new beta-blocker in the treatment of glaucoma].

During an open multicenter field study the new beta-blocking agent Carteolol, in 1% and 2% solution, proved to be effective and safe in the treatment of 178 patients suffering from glaucoma. On average, IOP was lowered by 5.8 to 18.7 mm Hg in nontreated and by 4.8 to 17.8 mm Hg in pretreated patients. In more than 90% of the cases both the patients and the investigators judged the treatment to be good, or better than the previous therapy. Side affects occurred in less than 3% of the cases.

Carteolol↗
PubMed1986

[Glaucoma visual fields and filtering operations].

Visual field defects already existing in 81 eyes prior to goniotrepanation (Elliot-Fronimopoulos) were followed up for up to 84 months postoperatively. In 11 eyes there were slight peripheral limitations due to cataract formation. In all of the other cases the visual fields were unchanged.

Follow-Up Studies↗
PubMed1986

[Defective artificial lenses].

The authors found the following defects in sterile-packed intraocular lenses, ready for implantation: the positioning holes had sharp edges; the lens surfaces were scratched from polishing and drilling; the lens loops were distinctly deformed. Following a description of these defects the possible clinical complications are discussed.

Humans↗