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Biomedical subjects

O Schwenn

Publications and source records attributed to O Schwenn.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Toric intraocular lens to correct high astigmatism after penetrating keratoplasty in a pseudophakic eye - a case report].

BACKGROUND: After penetrating keratoplasty residual astigmatism can be treated with various options. Correction with spectacles or contact lenses, methods such as radial keratotomy, photorefractive keratectomy (PRK) or Laser-in-situ keratomileusis (LASIK) are limited only to mild and moderate astigmatism. In laser ablation a sufficient corneal thickness must be ensured. On the other hand surgical correction is performed on transplanted tissue which can increase the risk of allograft rejection. In pseudophakic eyes the implantation of an individually designed toric intraocular lens (IOL) according to keratometry and biometry with a cylindrical power up to 12 D provides an alternative method for correcting higher astigmatism. This individually designed IOL can be implanted additionally to the existing IOL. CASE: A 66-year-old patient presented after penetrating keratoplasty and implantation of an IOL 4 years ago with a visual acuity of 20/160 and residual astigmatism of - 10 D x 151(o). After biometry an individually manufactured toric PMMA-IOL of + 12 D cylindrical and - 9.5 D spherical power was implanted via a sclerocorneal tunnel incision additionally to the existing IOL into the ciliary sulcus. Postoperatively a well centered and stable positioned IOL was found. One year after implantation of the toric IOL the position was still unchanged and the graft had remained clear. Spherical equivalent refraction was + 1,5 D - 3,0 D x 141(o), with an uncorrected visual acuity of 20/60. CONCLUSION: Implantation of a toric intraocular lens in pseudophakic eyes allows the correction of high astigmatism after penetrating keratoplasty. The advantage of this method compared to the keratorefractive options lies in its minor manipulation on the allograft.

Aged↗
PubMed2001

Effects of early postfiltration ocular hypotony on visual acuity, long-term intraocular pressure control, and posterior segment morphology.

PURPOSE: To determine whether hypotony after filtration surgery has any influence on visual acuity and intraocular pressure (IOP) lowering. PATIENTS AND METHODS: We prospectively investigated 43 eyes of 43 patients undergoing trabeculectomy without the use of antimetabolites for 12 months. RESULTS: The lowest postoperative IOP valued 4.9 +/- 3.6 mm Hg (range, 0-14 mm Hg). It correlated statistically significant with the IOP 6 weeks (P = 0.016), 6 months (P = 0.009), and 1 year after surgery (P = 0.027). Eyes with a deterioration of visual acuity 6 weeks after surgery had undergone a stronger postoperative hypotony (correlation with lowest postoperative IOP, P = 0.035). The mean period with an IOP less than 5 mm Hg was 3.5 +/- 8.0 days, and the mean period with an IOP less than 10 mm Hg lasted 45.4 +/- 68.8 days (range, 0-276 days). A hypotony score based on IOP and duration of hypotony was introduced. A correlation was detected between morphologic signs of hypotony, such as tiny retinal folds, at the 6-month follow-up and the duration of hypotony (P = 0.029) and hypotony score (P = 0.001). CONCLUSIONS: Hypotony after filtration surgery may decrease visual acuity in the early postoperative period. Conversely, early postoperative hypotony correlated with better long term IOP control. There was no deleterious effect on visual acuity after 6 months.

Adult↗
PubMed2000

[Trabeculotomy in congenital glaucoma: comparison to goniotomy].

PURPOSE: To compare the efficacy of trabeculotomy (TO) and that of goniotomy (GO) as a primary surgical procedure in congenital glaucoma. PATIENTS AND METHODS: We retrospectively analyzed 39 eyes of 22 children with congenital glaucoma who underwent TO with or without a small trabeculectomy. The results were compared to data on 34 eyes of 21 children who underwent GO for congenital glaucoma. RESULTS: The mean preoperative intraocular pressure (IOP) was 28.2 +/- 6.7 mmHg in TO eyes and 31.0 +/- 7.9 mmHg in GO eyes. Mean IOP at the end of follow-up was 17.7 +/- 6.0 mmHg in TO eyes and 18.9 +/- 9.1 mmHg in GO eyes. In 31 of 39 TO eyes (79.5%) and in 26 of 34 (76.5%) GO eyes the IOP was 21 mmHg or lower at the end of follow-up. Combining the criteria of an IOP greater than 21 and an IOP drop of at least 20%, the success rate was 71.8% (28/39) in TO eyes and 70.6% (24/34) in GO eyes. CONCLUSION: In this study the value of TO in controlling IOP was comparable to that of GO.

Child↗
PubMed2000

Healon5 versus Viscoat during cataract surgery: intraocular pressure, laser flare and corneal changes.

BACKGROUND: The use of a viscoelastic substance facilitates cataract surgery. Healon 5 is a new viscoelastic product with special rheological properties. We evaluated the postoperative effect of Viscoat and Healon5 on intraocular pressure (IOP), central corneal thickness (CCT), endothelial cell counts and laser flare. METHODS: Forty-eight eyes of 48 patients undergoing routine phacoemulsification followed by foldable IOL implantation were enrolled. Either Healon5 or Viscoat was used according to a block-randomization scheme. The aspiration technique was standardized. IOP, CCT, endothelial cell counts and laser flare were compared pre- and postoperatively. Statistical analysis was performed using the two-sample Wilcoxon test. Data description was based on median and quartiles, while graphic description was performed by non-parametric box plots. RESULTS: Viscoat demonstrated a statistically significant higher IOP than Healon5 at 4 and 8 h postoperatively (P< 0.01 and < 0.05, respectively). Further, the laser flare values were statistically significantly higher for the Viscoat than for the Healon5 group 8 h postoperatively (P<0.05). Endothelial cell loss did not differ significantly between the two groups (relative change in endothelial cell density after 3 months: -4.3% for the Healon5 group and -6.2% for Viscoat group). CONCLUSION: There was neither a statistically nor a clinically significant difference in endothelial cell loss after the use of Healon5 or Viscoat in routine cataract surgery. However, the IOP in the early postoperative period was higher in the Viscoat group than in the Healon5 group.

Adult↗
PubMed2000

Trabeculotomy in congenital glaucoma.

BACKGROUND: Congenital glaucoma is a potentially blinding disease that requires surgical therapy. This paper describes the outcome of trabeculotomy in primary congenital glaucoma. METHODS: Thirty-nine eyes of 22 children with congenital glaucoma who underwent trabeculotomy with or without a simultaneous trabeculectomy between 1992 and 1997 were retrospectively analyzed. RESULTS: Mean follow-up was 24.7+/-17.9 months. A mean of 1.3 operations per eye were performed. The mean IOP at the end of follow-up (n=39) was 17.7+/-6.0 mmHg; in 8 eyes (20.5%) the IOP was >21 mmHg, in 31 eyes (79.5%) it was < or =21 mmHg. The mean difference between pretreatment IOP and IOP at the end of follow-up (n=39) was -10.5+/-9.4 mmHg (-37.2%). Success rates were calculated: IOP was < or =21 mmHg in 36/39 eyes (92.3%) after 1/2 year of follow-up, in 25/27 eyes (92.6%) after 1 year, in 15/18 eyes (83.3%) after 2 years, in 8/12 (66.7%) eyes after 3 years, in 4/8 eyes (50%) after 4 years and in 4/4 (100%) eyes after 5 years of follow-up. Complications included hypotony (three eyes), subchoroidal bleeding (one eye ), detachment of Descemet's membrane (one eye) and macular pucker (one eye in which later mitomycin C was used). Visual acuity (VA) was tested with various methods in 35 eyes. VA was within the normal nomogram range in 12 eyes and below the normal range in 23 eyes at the end of follow-up. Axial length measurements showed normalization according to the age nomogram in 22 of 35 eyes. CONCLUSION: This study shows that trabeculotomy is an effective surgical procedure in congenital glaucoma with satisfactory success rates up to 5 years of follow-up.

Child↗
PubMed2000

Inflammation after sclerocorneal versus clear corneal tunnel phacoemulsification.

OBJECTIVE: To compare the postoperative inflammation after phacoemulsification followed by intraocular lens (IOL) implantation by means of sclerocorneal versus clear corneal tunnel incision. DESIGN: Randomized controlled clinical trial. PARTICIPANTS: One hundred eyes of 100 patients were examined at a German University eye hospital. INTERVENTION: One hundred eyes with cataract necessitating phacoemulsification with posterior chamber IOL implantation were randomly assigned to receive a temporal sclerocorneal or clear corneal tunnel incision by a single surgeon. MAIN OUTCOME MEASURES: Preoperative and postoperative inflammation was evaluated by measurement of flare using laser flare photometry. Statistical inference was mainly based on nonparametric group comparisons by use of two sample Wilcoxon tests. RESULTS: Mean anterior chamber flare in the group with sclerocorneal tunnel increased from 7.5 photon counts/ms preoperatively to 19.6 at 6 hours postoperatively and decreased to 11.1 (day 1), 11.7 (day 2), 11.6 (day 3), and 9.2 (5 months) during the postoperative course. The mean flare in the clear corneal tunnel incision group increased from 7.7 preoperatively to 12.9 at 6 hours postoperatively and then decreased to 9.2 (day 1), 9.8 (day 2), 9.1 (day 3), and 9.2 (5 months). Individual postoperative flare changes were significantly lower in the clear corneal tunnel group at the day of surgery (P<0.0001), as well as at day 1 (P = 0.0011), day 2 (P = 0.0079), and day 3 (P = 0.0020). After 5 months, no statistically significant difference was found. CONCLUSIONS: After phacoemulsification and foldable IOL implantation, postoperative alteration in the blood-aqueous barrier was statistically significantly lower with the clear corneal tunnel incision group compared with the sclerocorneal incision group, in the first 3 days postoperatively.

Adult↗
PubMed2000

Effect of large positioning holes on capsule fixation of plate-haptic intraocular lenses.

PURPOSE: To compare the centration and fixation of silicone plate-haptic intraocular lenses (IOLs) with different-sized positioning holes. SETTING: Eye Clinic of the Johannes Gutenberg-University Mainz, Mainz, Germany. METHODS: In a prospective randomized study, 51 Chiroflex C10 and 56 Chiroflex C11 IOLs were implanted under standardized conditions by the same surgeon. The IOL position was documented at the end of surgery and by retroillumination on the first day and 5 months postoperatively. The positioning-hole area was evaluated by ultrasound biomicroscopy (50 MHz) 5 months postoperatively. RESULTS: One day postoperatively, no IOL in either group was decentered more than 1.0 mm. After 5 months, 33% of the C10 and 42% of the C11 IOLs were decentered between 0.5 and 1.0 mm, and 11% of the C10 and 8% of the C11 IOLs were decentered more than 1.0 mm (maximum 1.23 mm and 1.41 mm, respectively). Up to the first postoperative day, 20% of the C10 and 22% of the C11 lenses were rotated more than 15 degrees. At 5 months, an additional 15% of the C10 and 19% of the C11 lenses were rotated. Ultrasound biomicroscopy showed no tissue or capsule adhesion in the holes in most cases (85% C10 group; 71% C11 group). No difference was statistically significant. CONCLUSIONS: Larger positioning holes did not prevent IOL decentration or rotation; thus, this IOL design appears unsuitable for correcting astigmatism. Because tissue in the positioning hole was rare with both lens types, it is doubtful that enlarged plate-haptic perforations will prevent IOL luxation into the vitreous cavity after capsulotomy.

Aged↗
PubMed2000

[Planning sample size in ophthalmologic studies].

An essential aspect in the cooperation of clinic and biometry consists in designing of studies, e.g. during the preparation of grant applications or for review by official drug surveillance institutions. A central aspect in study planning is the design-adequate and well-documented prediction of sample size, which should be recommended for any intended study. Based on several examples for sample size planning in study designs, which are of common relevance for ophthalmology, guidelines are derived to enable clinical researchers to perform sample size planning on their own. The latter can be based on the various available software packages for sample size prediction.

Bias↗
PubMed2000

Contrast sensitivity and glare disability by halogen light after monofocal and multifocal lens implantation.

BACKGROUND: Standard examination of contrast sensitivity under conditions of glare disability is performed with incandescent light. A new halogen glare test that simulates glare as seen with oncoming vehicle headlights was used to measure glare disability in patients implanted with multifocal and monofocal intraocular lenses (IOLs). METHODS: 28 patients with an average age of 69 years (SD 12 years) were implanted with a monofocal IOL (SI-40NB, Allergan) and 28 patients with an average of 66 years (12 years) were implanted with a refractive multifocal IOL (Array-SA-40N, Allergan). All patients were followed for 5 months postoperatively. Contrast sensitivity at four spatial frequencies (3, 6, 12, and 18 cycles per degree, cpd) with and without a glare source were measured using the halogen glare test (CSV-1000 HGT). Statistical analysis was performed using the two sample Wilcoxon test. The local significance level was set at 0.05. RESULTS: When tested at the lowest spatial frequency (3 cpd) without halogen glare, contrast sensitivity was lower in the multifocal group than in the monofocal group (p=0.0292). With additional glare, there was no difference between both groups. At all other spatial frequencies (6, 12, and 18 cpd), when tested without halogen glare (6 cpd, p=0.5250; 12 cpd, p=0.8483; 18 cpd, p=0.9496) and with moderate (3 cpd, p=0.7993; 6 cpd, p=0.4639; 12 cpd, p=0.7456; 18 cpd, p=1.0) and high halogen glare (3 cpd, p=0. 1513; 6 cpd, p=0.2016; 12 cpd, p=0.3069; 18 cpd, p=0.9933), there was no statistically significant difference between groups. Patients in both groups of age 70 or older had reduced contrast sensitivity without halogen glare and with moderate and strong glare. When monofocal and multifocal patients older than 70 years of age were analysed separately, there was no statistically significant difference in contrast sensitivity with and without glare. Astigmatism >1 dioptre had no significant influence on contrast sensitivity and glare disability when monofocal and multifocal eyes were compared. CONCLUSION: Reduced contrast sensitivity was found in the multifocal group only at the lowest spatial frequency without halogen glare. The monofocal and multifocal groups had no statistically significant differences in contrast sensitivity with moderate and strong glare. These results suggest no difference in glare disability induced by halogen light similar to oncoming vehicle headlights for patients implanted with monofocal and multifocal IOLs.

Adult↗
PubMed1999

[Capsular bent ring. Improvement of the capsular tension ring].

Since the first introduction of the capsular ring in 1991, the open capsular tension ring proved to be efficient in various indications and applications: e.g. in zonular dialysis or or weakness, with integrated tinted sector shield in sector or aniridia, to facilitate primary posterior capsulorhexis, for prophylaxis of intraocular lens decentration or as an intraocular measuring gauge. Nishi modified this capsular tension ring mainly by increasing the width to 0.7 mm and created a rectangular edge, thus facilitating the creation of a sharp, discontinuous bend in the equatorial capsule. This band-shaped, sharp-edged capsule-bending ring prevented the anterior capsule from coming into contact with the posterior capsule. This is most likely due to the 0.7 mm width of the capsule-bending ring, which significantly prevented anterior capsule opacification, which commonly occurs within one month postoperatively. Posterior capsule opacification seems to be reduced as well, but final evaluation is needed for a longer period of time. The capsular tension ring as well as the capsular bending ring enlarge our surgical options in modern cataract surgery. Both can be considered as a useful instrument and promising innovation.

Aged↗
PubMed1999

[Classification of visco-elastic substances for ophthalmologic surgery].

UNLABELLED: Individual properties of a viscoelastic substance for ophthalmologic applications are intimately tied to its chemical and rheologic characteristics. Independent comparative data for vicoelastic substances are not readily available or interpretable. MATERIAL AND METHODS: Twenty-six different commercially available viscoelastic substances were investigated using the Advanced Rheometric Expansion System and the Rheometric Scientific 800 device to analyze elastic and viscous modulus, complex viscosity (dynamic frequency dependance) and viscosity at the zero shear rate by extrapolation using the Ellis fit. RESULTS: Viscosity (cps) at zero shear rate (s-1, mean of six different samples): Sodium hyaluronate products: Amivisc Plus: 128; AMO Vitrax: 41; Biolon: 243; Dispasan: 130; Dispasan Plus: 782; Healon: 243; Healon GV: 2451; Healon 5: 5525; Microvisc (Morcher Oil): 1162; Microvisc Plus: 3663; Morcher Oil: 1253; Provisc: 207; Rayvisc: 78; Viscoat: 58; Viscorneal (Allervisc): 733; Viscorneal Plus (Allervisc Plus): 1176; Visko: 206; Visko Plus: 1683. Hydroxypropylmethylcellulose (HPMC) products: Acrivisc: 7; Adatocel: 8; Coatel: 6; HPMC Ophthal H: 94; HPMC Ophthal L: 7; Ocucoat: 6; PeHa-Visko: 5; Visco Shield: 60. CONCLUSION: Sodium hyaluronate as well as HPMC viscoelastic substances demonstrated remarkable differences in rheological properties from each other. In some cases, the results of this independent investigation differed from the values provided by the companies. A new division of commercially available viscoelastic substances into subgroups is presented, which provides a scientific base for various practical viscosurgical aspects. These real rheologic properties of each substance allow the ophthalmic surgeon to choose the viscoelastic substance that is most suitable for the surgical situation.

Adjuvants, Immunologic↗
PubMed1999

Objective and subjective evaluation of photic phenomena after monofocal and multifocal intraocular lens implantation.

OBJECTIVE: To objectively measure and compare halo, flicker, and glare disability in pseudophakic eyes with monofocal (MONO) and multifocal (MULTI) intraocular lenses (IOLs) with respect to the influence of corneal surface quality, astigmatism, and age. DESIGN: Prospective case series. PARTICIPANTS: This clinical trial involved 28 eyes of 28 patients after small-incision cataract surgery with a MONO silicone IOL and 28 eyes of 28 patients with zonal-progressive silicone IOL. INTERVENTION: A computer program objectively determined halo, glare, and flicker. Corneal surface quality and astigmatism were measured using computerized videokeratography. Ray-tracing analysis was performed based on the videokeratography data to calculate retinal peak distance and distortion index. A questionnaire was sent to all patients to evaluate the incidence of subjective photic phenomena. RESULTS: Mean halo size (square degrees +/- standard deviation) valued 6.1 (+/- 1.3) in the MONO group and 7.2 (+/- 2.3) in the MULTI group with no statistically significant difference between MONO and MULTI. Flicker (in % contrast to add) was -0.7 (+/- 2.9) in the MONO group and -1.0 (+/- 4.2) in the MULTI group with no statistical differences. Glare (in % contrast to add) was 5.5 (+/- 16.5) in the MONO group and 6.5 (+/- 18.0) in the MULTI group with no statistical differences. Patients in the MONO group older than 70 years of age had significantly more glare than those younger than 70 years (P = 0.017). In the MULTI group, patients with corneal shape irregularities (peak distance > 6.0 microm) or astigmatism (> 1 diopter) had statistically significant greater halos than did patients with regular corneal shape (peak distance < or = 6.0 microm) or astigmatism (< or = 1 diopter) (P < 0.005). Three of 27 MONO patients and 9 of 28 MULTI patients noticed light sensations (mainly halos) after surgery that were not present before surgery, with the majority not being bothered by these at all. CONCLUSION: In monofocal as well as in multifocal eyes, halo and glare disability occurred. Patient age, corneal surface quality, and IOL design played an important role in these photic phenomena. Because these photic phenomena may be more prevalent in night driving conditions, the authors' study suggests that night driving ability, especially in the elderly patient with pseudophakia, should be examined carefully.

Adult↗
PubMed1999

Implantation of the modified endocapsular bending ring in pediatric cataract surgery using a viscoadaptive viscoelastic agent.

Cataract surgery and intraocular lens (IOL) implantation in pediatric eyes remain controversial. Using a viscoadaptive viscoelastic agent, we implanted a modified capsular bending ring (CBR) as well as an acrylic IOL with a sharp-optic-edge design in the capsular bag. All operated eyes demonstrated a low postoperative inflammatory reaction and a clinically well-centered IOL. The band-shaped, sharp-edged CBR facilitates the creation of a sharp, discontinuous bend in the equatorial capsule, which prevents anterior and posterior capsule opacification. Combining the viscoadaptive viscoelastic agent and the CBR enhances the safety of primary and secondary posterior chamber IOL implantation in pediatric cataract surgery, reduces capsule opacification, and may facilitate IOL exchange.

Biocompatible Materials↗
PubMed1998

[Late dislocation of a plate haptic silicone lens into the vitreous body after Nd:YAG capsulotomy. A case report].

UNLABELLED: We describe a case that was referred 10 months after Nd:YAG laser treatment with a posteriorly dislocated silicone intraocular lens (IOL) into the vitreous cavity. PATIENT: A 70-year old white woman underwent uncomplicated phacoemulsification with in-the-bag placement of a Chiron silicone plate haptic lens through a 5.5- mm continuous circular capsulorhexis. The patient was fine until 9 months postoperatively when she complained of a decrease in visual acuity due to capsular fibrosis. A successful Nd:YAG laser capsulotomy was performed, resulting in an increase in visual acuity. Ten months later, the patient noted acute and atraumatic loss of vision, and the IOL was found to have dislocated posteriorly onto the retina. RESULTS: The dislocated IOL was removed via the anterior chamber following pars plana vitrectomy. Perfluorocarbon liquid was used to elevate the slippery lens from the retinal surface. The IOL was removed by a Sato Knife from the anterior chamber, followed by implantation of a one-piece PMMA IOL in the ciliary sulcus. CONCLUSION: Silicone plate haptic IOLs seem to present special risks for dislocation. Shrinkage of the anterior capsule exerts centripetal forces on the ends of the plate haptic, causing the optic to move posteriorly and to exert pressure against the posterior capsule. If either the posterior or anterior capsule is disrupted by Nd:YAG laser treatment, the forces created by capsular contraction against the flexible lens may cause extension of radial tears and appear to be a substantial risk for further capsule-tearing, releasing the IOL into the vitreous cavity, even months later. The forces of capsular contraction can impart a spring-loading effect on plate haptic silicone lenses. Due to inadequate capsular adherence, these lenses are at risk of posterior dislocation from capsular rents following Nd:YAG laser treatment.

Aged↗
PubMed1998

[Adhesion of liquid perfluorocarbon to various intraocular lens materials. A light microscopy study].

INTRODUCTION: Perfluorocarbone liquids (PFCL) enable explantation of intraocular lenses (IOL) dislocated into the vitreous. Because of their relatively high specific weight, the IOL can be floated off the retina and repositioned in the anterior segment. If the IOL surface is affected by contact with PFCL is still unknown. We were interested in the extent of PFCL contact with different IOL materials, having in mind a repositioning of a dislocated IOL into the posterior chamber. We investigated the adherence of PFCL to different IOL surfaces. MATERIALS AND METHODS: The following IOL materials were tested: Group I: acrylate/methacrylate polymers: (a) PMMA, compression molding; (b) PMMA, compression molding, heparin-surface modified; (c) poly-hydroxyethylmethacrylate (polyHEMA); (d) phenylethylacrylate, phenylethylmethacrylate; (e) methylmethacrylate, HEMA; (f) methylmethacrylate, hydroxyethylmethacrylate, ethylene glycol dimethacrylate; (g) hydroxyhexylmethacrylate, HEMA. Group II: silicone elastomers: (a) polydimethylsiloxane; (b) polydimethyldiphenylsiloxane. A total of 17 types of standard quality IOLs were obtained from several manufacturers. Each IOL was immersed in PFCL for 3 h. Then each IOL was rinsed with 2 ml balanced salt solution (BSS) and investigated by light microscopy with regard to the extent of PFCL adhesion. RESULTS: After rinsing with BSS, no PFCL was detectable on any IOL surface. Possible PFCL invasion into an open optic-haptic junction in three-piece IOLs could not be excluded using this method. All IOLs demonstrated optic and haptic surfaces without alterations. The IOL surfaces were comparable to those of new IOLs. CONCLUSIONS: With respect to PFCL-IOL interaction, all IOLs seem to be inert. After luxation of the IOL into the vitreous and IOL elevation by using PFCL, repositioning of the dislocated IOL seems to be possible under special conditions (adequate total diameter, IOL without damage, no open haptic junction in the optic). After rinsing the explanted IOL with BSS prior to reimplantation, the risk of damaging the eye by PFCL remnants on the IOL appears neglibile.

Fluorocarbons↗
PubMed1998

[An ophthalmologic image databank on the Internet].

The Internet has become a powerful, international source for information, and it has shown an exponential growth because of the ease of access and the immediate availability of information. We introduced a new ophthalmological atlas including ICD coding on the World Wide Web. So far, more than 500 lantern slides of typical and interesting ophthalmological findings have been selected and digitized. These pictures were integrated in a data base, which was arranged for ease and speed of search and retrieval. In its background, the data base contains a list of over 4700 ICD-encoded diagnoses to which the picture-documented findings are linked. Comments on pictures can be added by the author or by users. The data base contains several lists, such as a list of ICD codes and diagnoses, a list of all pictures with corresponding diagnoses, a list of all diagnoses and number of pictures, a list of those diagnoses for which the corresponding picture is available, as well as a list of comments on each picture. Special program scripts handle the user's search key words for diagnoses and extract the required information out of the data base, using Windows NT. Search results are presented on an automatically built-up webpage. To provide fast speed of search all pictures initially are shown in a small format (thumbnails) with little amount of data. The related full-size picture is retrieved by a single mouse click. Moreover, the name and institution of the author, diagnostical hints and comments on pictures by the author or by users are offered for each diagnosis available. The Giessen Ophthalmological Picture Atlas can be reached under www.med.unigiessen.de in the Internet. It allows a fast search free of charge from all over the world and, therefore, offers an additional option to obtain specific ophthalmological information for various purposes.

Databases, Factual↗
PubMed1998

[Molecular genetic study of the PAX6 gene in aniridia patients].

INTRODUCTION: Aniridia represents a congenital ocular disorder with partial or complete iris hypoplasia. The disorder is associated with poor vision, glaucoma, corneal and lenticular opacities, ectopia lentis due to abnormal zonula fibers, as well as optic nerve and macular abnormalities. Aniridia may present as either hereditary or sporadic cases. Some of the sporadic cases develop Wilms' tumor, frequently as part of the WAGR syndrome (Wilms' tumor, aniridia, genitourinary abnormalities and mental retardation). PAX6, a candidate gene located on chromosome 11p13, is often mutated in aniridia patients. The gene encodes a transcription regulatory protein. METHOD: Analysis of the PAX6 gene was done using PCR (polymerase chain reaction), SSCP (single strand conformation polymorphism) and DNA sequencing. RESULTS: In 13 of 20 aniridia patients a PAX6 gene mutation was found. CONCLUSION: The mutations result in a gene product with reduced function or a reduced PAX6 protein level. Molecular analysis of aniridia is also a valuable diagnostic tool for Wilms' tumor risk evaluation, as patients with proven PAX6 mutations--in contrast to cases with large deletions of the 11p13 region--are at no increased risk to develop Wilms' tumor.

Aniridia↗