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Dive into the research topics where Walter Konen is active.

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Featured researches published by Walter Konen.


Ophthalmology | 2001

Primary viscocanalostomy versus trabeculectomy in white patients with open-angle glaucoma: A randomized clinical trial

Christian P. Jonescu-Cuypers; Philipp C. Jacobi; Walter Konen; Günter K. Krieglstein

PURPOSE To compare viscocanalostomy, a nonpenetrating procedure for glaucoma treatment, with trabeculectomy. DESIGN Randomized controlled trial. PARTICIPANTS Twenty white subjects (20 eyes) with open-angle glaucoma with no history of surgery were enrolled. METHODS Ten subjects were randomly assigned to viscocanalostomy according to Stegmanns technique and 10 subjects to a modified Cairns trabeculectomy. A complete ophthalmologic examination was performed the day before surgery and postoperatively. Further visits were scheduled monthly for 6 to 8 months after surgery. MAIN OUTCOME MEASURES Success was defined as intraocular pressure (IOP) between 7 and 20 mmHg, with no medication. RESULTS After a mean follow-up of 6 months (range, 6-8 months), success was obtained in 5 of 10 cases in the trabeculectomy group and in no case in the viscocanalostomy group. With Kaplan-Meiers method, subjects with viscocanalostomy showed shorter postoperative IOP-reduction periods than subjects undergoing trabeculectomy. CONCLUSIONS According to the results of this short-term study, trabeculectomy was more effective than viscocanalostomy in lowering IOP in glaucomatous eyes of white patients.


British Journal of Ophthalmology | 2002

Ultrasound biomicroscopy and its value in predicting the long term outcome of viscocanalostomy.

Sigrid Roters; Christoph Lüke; Christian P. Jonescu-Cuypers; Bert Engels; Philipp C. Jacobi; Walter Konen; G. K. Krieglstein

Aims: To examine whether the early postoperative morphology at the site of sclerectomy, as visualised by ultrasound biomicroscopy (UBM), is an indicator of the mechanisms that lower intraocular pressure (IOP) and/or predictors of the long term outcome of viscocanalostomy. Methods: 15 eyes of 14 patients with medically uncontrolled open angle glaucoma and no history of surgery underwent viscocanalostomy according to Stegmann’s technique. Ultrasound biomicroscopy was performed during the first month after surgery. The following parameters were assessed: dimensions of the intrascleral “lake,” presence of a filtering bleb, presence of a subconjunctival cavity or a suprachoroidal hypoechoic area, and the thickness of the residual trabeculocorneal membrane. A complete ophthalmological examination was performed the day before and the day after surgery. Follow up visits were scheduled 1 week, 4 weeks, 6 months, and 12 months after surgery. Results: At 1 year successful control of IOP (<20 mm Hg) was achieved without further manipulation or medication in six of 15 eyes. The size of the intrascleral “lake” (average 0.62 mm3) did not correlate with later IOP; however, a visible route under the scleral flap and accidental perforation of the trabeculocorneal membrane were associated with long term lowering of IOP. Normal thickness of the trabeculocorneal membrane (0.10–0.15 mm) was indicative of IOP control with and without medication. When UBM showed an early collapse of the intrascleral cavity, control of IOP was not achieved. Other UBM findings did not predict long term function. Conclusion: In accordance with previous studies, the authors found that UBM examination is a useful method to evaluate outflow mechanisms after glaucoma surgery. This study shows that UBM imaging of external filtration during the early postoperative period can be used to predict the success of viscocanalostomy. However, to establish conclusively what parameters of UBM predict successful viscocanalostomy a larger number of patients must be studied.


Ophthalmology | 2001

Multifocal intraocular lens implantation in pediatric cataract surgery

Philipp C. Jacobi; Thomas S. Dietlein; Walter Konen

OBJECTIVE To evaluate implantation of a zonal-progressive multifocal intraocular lens (IOL) in children. STUDY DESIGN Prospective, noncomparative, interventional case series. PARTICIPANTS Thirty-five eyes of 26 pediatric patients aged 2 to 14 years with multifocal IOL implantation at one institution with more than 1 year of follow-up. INTERVENTIONS Standard surgical procedure comprised an anterior capsulorrhexis, lens material aspiration via two side-port incisions, temporal tunnel incision, and multifocal IOL (SA40-N; Allergan, Irvine, CA) implantation in all eyes. In 24 eyes (68%), a 5-mm posterior capsulorrhexis was created with forceps, followed by an anterior vitrectomy in 19 of those eyes (54%). RESULTS Twenty-six patients (35 eyes) had an average follow-up of 27.4 +/- 12.7 months (range, 12-58 months). At last follow-up, best-corrected distance visual acuity improved significantly (P = 0.001), 71% of eyes with a visual acuity of 20/40 or better and 31% of eyes with a visual acuity of 20/25 or better. In the 9 bilateral cases, spectacle dependency was moderate, with only 2 children (22%) reporting the permanent use of an additional near correction. The remaining children were either using distance-correction only (4 patients; 44%) or no glasses at all (3 patients; 33%). Stereopsis also improved significantly after multifocal IOL implantation (P = 0.01). Sixteen eyes (46%) experienced obscuration of the entrance pupil that required intervention, with 10 requiring a second intraocular surgery. Four eyes required an anterior membranectomy for persistent fibrinous membrane. Intraocular lens decentration requiring surgical intervention developed in six eyes. CONCLUSIONS Multifocal IOL implantation is a viable alternative to monofocal pseudophakia in this age group.


British Journal of Ophthalmology | 2003

A prospective randomised trial of viscocanalostomy with and without implantation of a reticulated hyaluronic acid implant (SKGEL) in open angle glaucoma

Christoph Lüke; Thomas S. Dietlein; Philipp C. Jacobi; Walter Konen; G. K. Krieglstein

Aim: To prospectively assess the efficacy and complications of viscocanalostomy with a reticulated hyaluronic acid implant (VSRHAI) versus standard viscocanalostomy in patients with medically uncontrolled open angle glaucoma. Methods: A consecutive series of 40 patients (40 eyes) with uncontrolled open angle glaucoma underwent non-penetrating antiglaucomatous surgery. After the excision of the deep scleral flap they were randomly assigned to either a standard viscocanalostomy or additional implantation of a reticulated hyaluronic acid implant. Follow up visits were over a period of 12 months after surgery. Results: The mean preoperative intraocular pressure (IOP) was 26.5 (SD 6.1) mm Hg for all patients enrolled. The mean IOP was 8.1 (SD 5.6) mm Hg 1 day after surgery for the viscocanalostomy group (p<0.001) and 12.0 (SD 5.2) mm Hg for the VSRHAI group (p<0.001). The postoperative IOP difference between the two groups was statistically significant (p = 0.03). The success rate, defined as an IOP lower than 22 mm Hg without medication, was 40% in both groups at 12 months postoperatively (p = 0.90). The number of postoperative complications was equally low for both groups. Conclusions: Both surgical procedures, viscocanalostomy and VSRHAI, provide comparable success rates over a 1 year follow up period. The specific intraoperative and postoperative complications of non-penetrating surgery were seen in our series, although the overall rate of postoperative complications proved equally low for both techniques.


Journal of Cataract and Refractive Surgery | 1996

Efficacy and tolerance of diclofenac sodium 0.1%, flurbiprofen 0.03%, and indomethacin 1.0% in controlling postoperative inflammation.

Michael Diestelhorst; Bernhard Schmidl; Walter Konen; Ulrich Mester; Palaniswamy Sunder Raj

Purpose: To compare the anti‐inflammatory effect of diclofenac sodium 0.1 % ophthalmic solution, flurbiprofen 0.03% ophthalmic solution, and indomethacin 1.0%. Setting: Department of Ophthalmology, University of Köln, and Bundesknappschaftskrankenhaus, Sulzbach, Germany. Methods: One hundred seventeen patients enrolled in this prospective, randomized, double‐masked, and parallel‐group study had phacoemulsification and intraocular lens implantation and received one of the three solutions. Preoperatively at day 1 and postoperatively at day 4 or 5 and day 12, 13, or 14, they were examined by slitlamp, applanation tonometry, and laser flare meter. Results: Anterior chamber flare reduction from baseline was significantly greater in the diclofenac group than in the flurbiprofen group (P = .022). Patients in the diclofenac group had significantly less burning and stinging than those in the flurbiprofen and indomethacin groups at postoperative days 4–5 and 12–14 (P = .001). Conclusion: Diclofenac sodium appeared to be more potent than flurbiprofen in controlling intraocular inflammation after cataract surgery and appeared to be locally tolerated better than flurbiprofen and indomethacin.


Journal of Cataract and Refractive Surgery | 1995

Effect of age and astigmatism on the AMO array multifocal intraocular lens

Philipp C. Jacobi; Walter Konen

Abstract Multifocal intraocular lenses (MIOLs) have been designed to provide better uncorrected near visual acuity than monofocal IOLs. However, the increase in depth of focus is combined with a significant decrease in contrast sensitivity and glare. We implanted a new zonal‐progressive MIOL (AMO Array) in 31 eyes of 25 patients whose mean age was 60.8 ± 13.5 years. At 12.1 ± 2.4 months postoperatively, the uncorrected visual acuity averaged 0.56 ± 0.09 (20/32) for distance and 0.54 ± 0.12 (20/40) for near focus. Seventy‐five percent of patients achieved a best corrected distance visual acuity of ≥0.9 (20/22). With distance correction only, mean near visual acuity was 0.72 ± 0.17 (20/25). Best corrected near acuity reached 0.89 ± 0.11 (20/22), requiring an additional near add of +1.0 to +2.0 diopters (D). We observed an age‐dependent difference in the depth of focus. In younger patients (46 ± 6 years), the pseudoaccommodation range was 6.25 D; acuity attained was ≥0.4 (20/50). In older patients (71 + 7 years), visual acuity at the near focus was substantially reduced (two lines). Regan contrast sensitivity was lower for MIOL patients at all contrast levels, but the difference was statistically significant only at very low contrast (11 %). Contrast sensitivity and glare were dependent on the patient’s age but did not change with the amount of postoperative astigmatism. Younger patients were very satisfied with the results of MIOL implantation, and the small loss of contrast sensitivity was counterbalanced by the advantage of improved depth of focus and uncorrected near visual acuity.


Graefes Archive for Clinical and Experimental Ophthalmology | 2000

Variability of dissection depth in deep sclerectomy: morphological analysis of the deep scleral flap

Thomas S. Dietlein; Christoph Lüke; Philipp C. Jacobi; Walter Konen; Günder K. Krieglstein

Abstract Background: Deep sclerectomy and similar procedures including a deroofing of Schlemm’s canal are meeting with increasing interest owing to the limited risk profile of non-perforating glaucoma surgery. The aim of our study was to investigate how often the outer wall of Schlemm’s canal or parts of the trabecular meshwork were incorporated in the excised tissue on deep scleral flap dissection by an experienced glaucoma surgeon.  Methods: The excised deep scleral flap was prepared for light microscopy after performing deep sclerectomy in 7 children and 22 adult patients suffering from glaucoma. Meridional serial sections were checked for the presence of fragments of trabecular beams and collector channels and parts of the endothelial wall of Schlemm’s canal. Morphology was compared with the intraoperative appearance of the operated tissue. Results: In 15 patients (52%) the deep scleral flap contained at least some tissue from the outer wall of Schlemm’s canal; in 5 of these 15 patients noticeable remnants of the juxtacanalicular trabecular meshwork were also found, although only in one patient was this obvious during surgery. In 14 patients (48%) no evidence of the deroofing of Schlemm’s canal was found within the excised deep scleral flap, although intraoperatively the dissection seemed to have been too superficial in only 5 patients. Conclusion: Even when performed by an experienced glaucoma surgeon, deep sclerectomy produces biopsy material of remarkable morphological variability that does not always correspond to the intraoperative appearance of the site of operation. More than in conventional trabeculectomy this variability may be of importance for the outcome of surgery.


Journal of Cataract and Refractive Surgery | 2000

Complications of endocapsular tension ring implantation in a child with Marfan’s syndrome

Thomas S. Dietlein; Philipp C. Jacobi; Walter Konen; Günter K. Krieglstein

A 4-year-old boy with Marfans syndrome had severe visual impairment after subluxation of the crystalline lens with bisection of the pupil. In the first eye, a capsular tension ring and an intraocular lens (IOL) were uneventfully placed in the capsular bag after phacoemulsification. During implantation of the endocapsular tension ring in the second eye, an inadvertent tear of the anterior capsule occurred, and the posterior chamber IOL was placed in the sulcus. In both eyes, severe lens epithelial proliferation with secondary IOL decentration developed postoperatively. Several surgical revisions were necessary to keep the IOL within the optical axis. In the eye with the sulcus-implanted IOL, the endocapsular tension ring was markedly decentered.


International Ophthalmology | 1991

The effect of flurbiprofen 0.03% eye drops on the blood aqueous barrier in extracapsular cataract extraction with IOL implantation

Michael Diestelhorst; F. Aspacher; Walter Konen; G. K. Krieglstein

Preoperative and postoperative anterior chamber fluorophotometry were performed after intravenous administration of fluorescein sodium in patients undergoing extracapsular extraction and posterior chamber lens implantation. The topical application of aqueous flurbiprofen sodium 0.03% solution before and after surgery significantly decreased the surgery mediated disturbance of the blood aqueous barrier as compared to vehicle application (placebo controlled). In contrast to similar studies, cortical steroids were not given topically or systemically to either group of patients during the study. The present fluorophotometric results correlate well with slitlamp biomicroscopy of postoperative inflammation. The data of this study indicate that flurbiprofen ophthalmic solution is effective in protecting the blood aqueous barrier (BAB) in human eyes during cataract surgery and IOL implantation.


Graefes Archive for Clinical and Experimental Ophthalmology | 1992

Effect of dexamethasone 0.1% and prednisolone acetate 1.0% eye drops on the blood-aqueous barrier after cataract surgery: a controlled randomized fluorophotometric study

Michael Diestelhorst; F. Aspacher; Walter Konen; G. K. Krieglstein; R. D. Hilgers

Using non-invasive anterior chamber fluorophotometry, we performed a double-blind, randomized clinical trial on the effects of dexamethasone 0.1% and prednisolone acetate 1.0% eye drops on the blood-aqueous barrier after phacoemulsification and posterior chamber lens implantation. Twenty patients received one of the preparations topically to the surgically treated eye 5 times daily for a period of 5 days, beginning the day after surgery. Patients chosen for the study had no history of eye disease other than senile cataract nor of systemic diseases influencing the eyes. No other steroids or non-steroidal anti-inflammatory drugs were given before or during the investigation. The fluorometric data measured 5 days after surgery show a lower mean concentration of fluorescein in the dexamethasone alcohol 0.1% treated group compared with the prednisolone acetate 1.0% treated group. The difference is statistically not significant. The clinical assessment of postoperative ocular inflammation did correlate with the fluorophotometric measurements. The results of the study indicate that although dexamethasone is the more potent anti-inflammatory agent, with a better binding affinity to glucocorticoid receptors, we are — with the number of cases measured — unable to demonstrate any difference in the efficacy in protecting the blood-aqueous barrier after cataract extraction and posterior chamber lens implantation to prednisolone acetate.

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