Biomedical subjects

Wolf Buehl

Publications and source records attributed to Wolf Buehl.

33 records · Page 2Linked to original sources

PubMed2004

Influence of optic edge design and anterior capsule polishing on posterior capsule fibrosis.

PURPOSE: To evaluate the role of posterior optic edge design and the effect of anterior capsule polishing on peripheral fibrotic posterior capsule opacification (PCO). SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: This randomized prospective study comprised 144 eyes of 72 patients with bilateral age-related cataract. Each patient had standardized cataract surgery in both eyes by the same surgeon. Group 1 (46 patients) received a round-edged hydrophobic acrylic IOL (AMO Sensar AR40) in 1 eye and a sharp-edged hydrophobic acrylic IOL (AMO Sensar OptiEdge AR40e) in the other eye. Group 2 (26 patients) received a silicone IOL (Pharmacia CeeOn 911A) with a truncated optic in both eyes. In this group, the anterior capsule was extensively polished in 1 eye and was left unpolished in the other eye. Digital slitlamp photographs were taken 1 year postoperatively using a standardized photographic technique for fibrotic PCO. The intensity of PCO was subjectively graded (score 0 to 4) by 2 masked examiners. RESULTS: Subjective PCO scores correlated well between the 2 examiners (r = 0.88). In Group 1, the mean PCO score was 0.26 for the OptiEdge AR40e IOL and 0.90 for the AR40 IOL (P<.01). In Group 2, the mean PCO score was 0.24 in eyes with a polished capsule and 0.17 in eyes in which the capsule was not polished (P =.31). CONCLUSIONS: The sharp-edged OptiEdge AR40e IOL led to significantly less peripheral fibrotic PCO 1 year postoperatively than the round-edged AR40 IOL. In eyes with the sharp-edged silicone 911A IOL, anterior capsule polishing caused no significant difference in fibrotic PCO.

Acrylic Resins↗

PubMed2004

Effect of intraocular lens optic edge design and material on fibrotic capsule opacification and capsulorhexis contraction.

PURPOSE: To examine the influence of intraocular lens (IOL) optic edge design and optic material on fibrosis of the anterior and peripheral posterior capsules and on capsulorhexis contraction. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: This randomized controlled patient- and examiner-masked study comprised 210 eyes of 105 patients with bilateral age-related cataract. In Group 1 (n = 53), the Sensar OptiEdge AR40e hydrophobic acrylic IOL with a sharp posterior optic edge was compared with the AR40 acrylic IOL with a round edge. In Group 2 (n = 52), the ClariFlex OptiEdge silicone IOL with a sharp posterior optic edge was compared with the PhacoFlex SI-40 silicone IOL with a round edge All IOLs were manufactured by Advanced Medical Optics, Inc. Standardized digital slitlamp images of anterior capsule opacification (ACO) and fibrotic posterior capsule opacification (PCO) were taken 1 year postoperatively, and digital retroillumination images were taken at 1 week and 1 year. The intensity of fibrotic PCO was graded subjectively (score 0 to 4), ACO was graded objectively (score 0% to 100%), and the capsulorhexis area (mm(2)) was determined objectively. RESULTS: One year after surgery, the mean ACO score was 32% in eyes with the sharp-edged acrylic IOL and 29% in eyes with the round-edged acrylic IOL (P<.05). In the silicone group, the mean was 31% and 26%, respectively (P<.05). The mean fibrotic PCO score was lower in eyes with a sharp-edged acrylic IOL than in eyes with a round-edged acrylic IOL (0.26 and 0.93, respectively; P<.05) and in eyes with a sharp-edged silicone IOL than in eyes with a round-edged silicone IOL (0.24 and 0.82, respectively; P<.001). At 1 year, the mean capsulorhexis area was statistically significantly smaller in eyes with a sharp-edged silicone IOL than in eyes with a round-edged silicone IOL (P<.05). CONCLUSIONS: Acrylic and silicone IOLs with the sharp OptiEdge design led to significantly less fibrotic PCO but more ACO than round-edged acrylic and silicone IOLs. The sharp-edged silicone IOL caused significantly more capsulorhexis contraction than the round-edged silicone IOL and both acrylic IOLs.

Acrylic Resins↗

PubMed2004

Effect of a silicone intraocular lens with a sharp posterior optic edge on posterior capsule opacification.

PURPOSE: To compare the inhibiting effect on posterior capsule opacification (PCO) of a silicone intraocular lens (IOL) with a sharp posterior optic edge (ClariFlex OptiEdge, Advanced Medical Optics) and a silicone IOL with a round optic edge (PhacoFlex SI-40, Advanced Medical Optics). SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: This prospective randomized patient- and examiner-masked study comprised 104 eyes of 52 patients with bilateral age-related cataract. All patients had cataract surgery in both eyes and received a sharp-edged IOL in 1 eye and a round-edged IOL in the other eye. Postoperative examinations were at 1 week, 1 and 6 months, and 1 year. Digital slitlamp and retroillumination images were taken of each eye. The amount of PCO was assessed subjectively at the slitlamp and objectively using Automated Quantification of After-Cataract (AQUA) automated-image analysis software. RESULTS: The sharp-edged IOL group had significantly less regeneratory and fibrotic PCO 1 month, 6 months, and 1 year after surgery. The mean AQUA PCO score (scale 0 to 10) was 0.71 in the sharp-edged IOL group and 1.40 in the round-edged IOL group (P<.001). The sharp-edged IOL group had less peripheral fibrotic PCO. There was no significant difference between the 2 IOL groups in patient reports of edge glare. CONCLUSION: The sharp-edged design of the ClariFlex OptiEdge silicone IOL led to significantly less PCO than the round-edged PhacoFlex SI-40 IOL 1 year postoperatively.

Aged↗

PubMed2004

Effect of anterior capsule polishing on fibrotic capsule opacification: three-year results.

PURPOSE: To evaluate the long-term effect of anterior capsule polishing on anterior capsule opacification (ACO) and peripheral fibrotic posterior capsule opacification (PCO). SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: This randomized double-blind study comprised 104 eyes of 52 patients with bilateral age-related cataract. All patients received round-edged intraocular lenses (IOLs); 26 received an SI-40 IOL (Advanced Medical Optics Inc.) in both eyes, and 26 received a Silens6 IOL (Domilens) in both eyes. Both IOLs consist of different silicone material and have different haptic angulation. The SI-40 IOL has 13.0 mm open-loop poly(methyl methacrylate) (PMMA) haptics angulated by 10 degrees. The Silens6 IOL has 12.5 mm open-loop PMMA haptics with no angulation. In 1 eye, the anterior capsule was extensively polished. The anterior capsule was left unpolished in the contralateral eye, which acted as a control. Digital slitlamp photographs of the ACO and fibrotic PCO were taken with a standardized technique for 3 years postoperatively. The intensity of ACO was measured objectively (score 0% to 100%) using Adobe Photoshop software. Fibrotic PCO was graded subjectively (score 0 to 4). RESULTS: The mean ACO was 17% in the polished eyes and 26% in the control eyes (P = .0001). The mean fibrotic PCO score was 0.5 and 1.0, respectively (P = .0007). The mean ACO was 15% in the polished SI-40 eyes and 26% in the control SI-40 eyes (P = .01). It was 19% in the polished Silens6 eyes and 26% in the control Silens6 eyes (P = .003). The mean fibrotic PCO score was 0.4 in the polished SI-40 eyes and 1.1 in the control SI-40 eyes (P = .0006). It was 0.6 in the polished Silens6 eyes and 0.9 in the control Silens6 eyes (P = .08). CONCLUSIONS: Three years after surgery, eyes in which the anterior capsule was extensively polished had less ACO and fibrotic PCO with both round-edged silicone IOLs. In eyes with Silens6 IOLs, however, the reduction in fibrotic PCO was not significant.

Aged↗

PubMed2004

Laserinterferometric assessment of pilocarpine-induced movement of an accommodating intraocular lens: a randomized trial.

PURPOSE: To measure the axial movement of an accommodating intraocular lens (IOL) induced by ciliary muscle contraction after application of pilocarpine. DESIGN: Randomized, controlled, patient- and examiner-masked trial with intrapatient comparison. PARTICIPANTS AND CONTROLS: One hundred ten eyes of 55 patients with age-related bilateral cataract. METHODS: This study was divided into 3 parts. In the first, the accommodating IOL (1CU) was compared with a 3-piece open-loop acrylic IOL that served as the control. In the second, to assess the effect of capsule fibrosis on the potential accommodating performance of the accommodating IOL, extensive polishing of the anterior capsule with a slit cannula was compared with standard surgery. In the third, the effect of a posterior capsulorhexis was compared with that of standard surgery. Anterior chamber depth (ACD) was assessed with partial coherence interferometry, measured before and after topical application of pilocarpine 2%, and near visual acuity (VA) was evaluated 3 months after surgery. MAIN OUTCOME MEASURE: Pilocarpine-induced change in ACD. RESULTS: The accommodating IOL showed a forward movement under pilocarpine with a median amplitude of movement of -314 microm (95% confidence interval [CI]: -148 to -592), compared with the backward movement of 63 microm (95% CI: 161 to -41) for the open-loop control IOL (P = 0.001). Capsule polishing and a posterior capsulorhexis had no effect on IOL movement with the accommodating IOL. The median near VA with distance correction was 20/60. CONCLUSION: Pilocarpine induced a small but significant forward movement of the accommodating IOL. However, the amount of movement was calculated to result in a refractive change of <0.5 diopters (D) in most patients, reaching 1 D or slightly more in only single cases, with a large variability of movement. Neither polishing of the capsule bag nor a posterior capsulorhexis could enhance the accommodative ability.

Accommodation, Ocular↗

PubMed2004

Comparison of posterior capsule opacification between the 1-piece and 3-piece Acrysof intraocular lenses: two-year results of a randomized trial.

PURPOSE: To compare intensity of posterior capsule opacification (PCO) between the 1-piece and 3-piece haptic designs of an open-loop hydrophobic acrylic intraocular lens (IOL). DESIGN: A randomized, patient- and examiner-masked clinical trial with intraindividual comparison. PARTICIPANTS: Fifty-two patients with bilateral age-related cataract (104 eyes). METHODS: Each patient had cataract surgery in both eyes and received a 1-piece Acrysof IOL in one eye and a 3-piece Acrysof IOL in the fellow eye. Follow-up examinations were at 1 week, 1 month, 6 months, 1 year, and 2 years. Patients were examined at the slit lamp, visual acuity (VA) was determined, and standardized high-resolution digital retroillumination images of the posterior capsule were taken. The intensity of PCO was assessed subjectively at the slit lamp and objectively using automated image analysis software. MAIN OUTCOME MEASURE: Posterior capsule opacification score (scale, 0-10). RESULTS: There was no significant difference between IOL styles in best-corrected VA, rhexis/IOL overlap, capsular folds, and amount of anterior capsule opacification during the follow-up period. One year postoperatively, the amount of regeneratory PCO was higher for the 1-piece Acrysof eyes (image analysis software score: 1.3) than for the 3-piece Acrysof eyes (score: 0.9; P = 0.002). However, 2 years postoperatively, there was no significant difference between the 2 IOL styles (1-piece: 1.5; 3-piece: 1.3; P = 0.3). Neodymium:yttrium-aluminum-garnet capsulotomy was not performed in the study. CONCLUSION: One year postoperatively, the 1-piece Acrysof showed slightly more regeneratory PCO than the 3-piece Acrysof. However, 2 years postoperatively, the barrier effect of the 1-piece design was comparable to that of the 3-piece haptic design, with low PCO intensity.

Acrylic Resins↗

PubMed2004

Effect of haptic design on change in axial lens position after cataract surgery.

PURPOSE: To compare the postoperative changes in anterior chamber depth (ACD) between single-piece and multipiece AcrySof intraocular lenses (IOLs) (Alcon Laboratories, Inc.) and their effect on the postoperative refractive shift. SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: This prospective randomized bilateral study with intraindividual comparison comprised 104 eyes of 52 consecutive patients with age-related cataract. All patients had standardized cataract surgery with a temporal self-sealing incision, phacoemulsification, and IOL implantation in the capsular bag. The first 30 patients received a single-piece, 5.5 mm optic IOL (AcrySof SA30) in 1 eye and a multipiece IOL (AcrySof MA30) in the other eye. Another 22 patients received the corresponding 6.0 mm optic models (AcrySof SA60 and AcrySof MA60, respectively). Anterior chamber depth measurements and evaluation of the change in ACD during the first 6 postoperative months were performed using partial coherence laser interferometry. The amount of change in capsulorhexis size during the first 6 postoperative months was assessed using standardized retroillumination photographs. RESULTS: Single-piece IOLs shifted significantly less postoperatively than multipiece IOLs. The multipiece IOLs shifted forward, especially from 1 day to 1 month. The change in the capsulorhexis area was similar between IOL types. CONCLUSIONS: Single-piece AcrySof IOLs shifted minimally after the first postoperative day; therefore, the prescription for spectacles in eyes with this IOL can be obtained soon after surgery.

Anterior Chamber↗

PubMed2004

Ocular blood flow and systemic blood pressure in patients with primary open-angle glaucoma and ocular hypertension.

PURPOSE: There is evidence that altered optic nerve head (ONH) blood flow may play a role in the development and progression of glaucoma. In the present study, the baseline characteristics were examined in a study population participating in a clinical trial in which the ocular hemodynamic effects of timolol and dorzolamide were compared. METHODS: One hundred forty patients with primary open-angle glaucoma (POAG) or ocular hypertension (OHT) were included in this trial and their baseline parameters compared with those of a group of 102 age-matched control subjects. Scanning laser Doppler flowmetry was used to measure blood flow in the temporal neuroretinal rim and the cup of the ONH. Pulsatile choroidal blood flow was assessed by laser interferometric measurement of fundus pulsation amplitude. In addition, hemodynamic parameters and mean arterial pressure were calculated in both groups. RESULTS: All ocular hemodynamic parameters were significantly lower in the POAG/OHT group compared with the healthy control group (P < 0.001 each). In addition, a significant positive correlation between laser Doppler flowmetry readings and mean arterial pressure was observed in patients with glaucoma but not in healthy control subjects. Likewise, the correlation coefficient between fundus pulsation amplitude and mean arterial pressure was higher in patients with glaucoma than in healthy control subjects. CONCLUSIONS: The present study indicates reduced ONH and choroidal blood flow and an abnormal association between blood pressure and ocular perfusion in patients with primary open-angle glaucoma or ocular hypertension, independent of topical antiglaucoma medication. Hence, vascular dysregulation appears to be an early manifestation in glaucoma that is not caused by pharmacologic intervention.

Antihypertensive Agents↗

PubMed2003

Comparison of 4 methods for quantifying posterior capsule opacification.

PURPOSE: To compare the results of posterior capsule opacification (PCO) quantification and the repeatability of a fully automated analysis system (Automated Quantification of After-Cataract [AQUA]) with that of 2 other quantification methods and subjective grading of PCO. A test set of digital retroillumination images of 100 eyes with PCO of varying degrees was used. SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: One hundred digital retroillumination images of eyes (100 patients) with PCO were selected to attain an even distribution from mild to severe cases. The images were evaluated by 4 methods: subjective grading by 4 experienced and 4 inexperienced examiners, the subjective Evaluation of Posterior Capsular Opacification (EPCO) system, posterior capsule opacification (POCO) software, and the AQUA system. Ten images were presented twice to assess the reproducibility of the analysis systems. RESULTS: Subjective grading correlated best with the subjective EPCO system and the objective AQUA system (r = 0.94 and r = 0.93, respectively). The POCO system showed very early saturation and therefore a much weaker correlation (r = 0.73). The POCO scores reached the maximum of 100% in several minimal to mild PCO cases. The reproducibility of the AQUA software was perfect and that of the other analysis systems, comparably satisfactory. CONCLUSION: The objective AQUA score correlated well with subjective methods including the EPCO system. The POCO system, which assesses PCO area, did not adequately describe PCO intensity and includes a subjective step in the analysis process. The AQUA system could become an important tool for randomized masked trials of PCO inhibition.

Cataract↗

PubMed2003

Postoperative change in effective lens position of a 3-piece acrylic intraocular lens.

PURPOSE: To study the change in postoperative position of an angulated, 3-piece, foldable acrylic intraocular lenses (IOLs) and evaluate the effect of a sharp posterior optic edge compared with that of a round optic edge on the change in postoperative anterior chamber depth (ACD). SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: This randomized intraindividual-comparison study comprised 104 eyes of 52 patients with age-related cataract. Patient received a sharp-edged Sensar OptiEdge AR40e IOL (Allergan Surgical) in 1 eye and a round-edged Sensar AR40 IOL in the other eye. Postoperative follow-up included ACD measurement by partial coherence interferometry and evaluation of the capsulorhexis area by standardized retroillumination photography at 1 day, 1 week, and 1 and 6 months. RESULTS: A decrease in ACD during the first postoperative week was followed by a small increase in ACD during the first 6 months. There was no significant difference between the sharp-edged group and the round-edged group. CONCLUSIONS: The angulated 3-piece acrylic IOLs showed significant forward movement over the first postoperative 6 months. Although the change in refraction was small, there was variability among patients. The sharp posterior optic edge design did not affect the IOL's movement in the capsular bag.

Acrylic Resins↗

PubMed2003

Influence of intraocular lens material on regeneratory posterior capsule opacification after neodymium:YAG laser capsulotomy.

PURPOSE: To evaluate the influence of a neodymium:YAG (Nd:YAG) laser capsulotomy on the morphology and development of regeneratory opacification of the remaining surrounding posterior capsule. SETTING: Department of Ophthalmology, Medical School, University of Vienna, Vienna, Austria. METHODS: Standardized digital retroillumination photographs were taken immediately before and after Nd:YAG laser capsulotomy and at 1 week, 6 months, and 1 to 3 years in 38 eyes of consecutive patients. Changes in regeneratory posterior capsule opacification (PCO) and opacification around the capsulotomy opening were evaluated. The influence of the type of intraocular lens (IOL) material and design (acrylic, n = 8; hydrogel, n = 8; silicone open loop, n = 11; silicone plate haptic, n = 6; poly(methyl methacrylate) [PMMA], n = 5) was assessed. The state of the anterior vitreous surface was examined at the slitlamp in all eyes. RESULTS: In 8 of 17 eyes with a silicone IOL, reduced regeneratory PCO was observed. Massive pearl formation on the margin of the Nd:YAG capsulotomy was typical with silicone IOLs (8 eyes) but also occurred with PMMA IOLs. Eyes with acrylic IOLs had no change in regeneratory PCO after the capsulotomy. Three of 8 eyes with hydrogel IOLs had complete closure of the posterior capsulotomy opening. CONCLUSIONS: Neodymium:YAG laser capsulotomy induced changes in the development and morphology of regeneratory PCO. Silicone and PMMA IOLs led to significant pearl formation on the capsulotomy margin, often combined with a reduction of peripheral regeneratory PCO (silicone). Hydrogel IOLs led to a higher incidence of reclosure of the Nd:YAG capsulotomy opening.

Acrylic Resins↗

PubMed2003

Removal of reflections in the photographic assessment of PCO by fusion of digital retroillumination images.

PURPOSE: Automated image-analysis systems for objective assessment of posterior capsule opacification (PCO) depend on good image quality. One major drawback is the existence of light-reflection artifacts (Purkinje spots) in retroillumination images of the posterior capsule. Therefore, a software algorithm was developed that removes these artifacts by fusion of two or more digital images from the same eye, photographed in slightly different directions of gaze. METHODS: The image-fusion process comprises five steps: definition of a primary and a secondary image, automated segmentation of the region of interest and the Purkinje spots, manual selection of three pairs of corresponding points in both images, geometric registration and radiometric calibration of the regions to be inserted from the secondary image into the primary image. The program was tested with an image set of 30 eyes that had various degrees of PCO. A digital image acquisition system with a coaxial optical path was used to take retroillumination images from each eye in at least three different directions of gaze. RESULTS: In 28 cases all light-reflection artifacts within the capsulorrhexis rim could be removed entirely. In two cases, small parts of single Purkinje spots remained visible, because the reflections were located too closely in the primary and the secondary images. CONCLUSIONS: Fusion of digital retroillumination images provides high-quality, reflection-free PCO images. This allows objective PCO assessment systems to analyze 100% of the posterior capsule, leading to more accurate results.

Algorithms↗

PubMed2002

Reproducibility of standardized retroillumination photography for quantification of posterior capsule opacification.

PURPOSE: To determine the short-term reproducibility of standardized digital retroillumination images of regeneratory posterior capsule opacification (PCO) using the photographic setup at 1 institution. SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: In this prospective study, 60 retroillumination images of 30 eyes with varying degrees of PCO and different types of intraocular lenses were acquired with a standardized digital coaxial retroillumination system. Two images were taken per eye with a 1-minute interval between images. Ten other eyes were photographed in the same way but with a 5-day interval between the 2 images. All images were evaluated with a fully automated, objective PCO analysis software in which the PCO score was from 0 to 100. The 2 results (A, B) in each eye were compared, and the differences were calculated. RESULTS: There was a high correlation between the A and B results (r = 0.99). The mean absolute difference was 3.7%. The repeatability coefficient was 8.8%. CONCLUSION: Digital coaxial retroillumination photography provided quick acquisition of regeneratory PCO images. It provided excellent image quality and high reproducibility. The technique forms a good basis for automated quantification of PCO with new software systems.

Cataract↗

PubMed2002

Assessment of anterior capsule opacification: photographic technique and quantification.

PURPOSE: To develop and evaluate a standardized slitlamp photographic technique to document and quantify anterior capsule opacification (ACO) in the pseudophakic eye. SETTING: University of Vienna, Medical School, Department of Ophthalmology, Vienna, Austria. METHODS: In this prospective study, slitlamp photographs were taken in 29 eyes of 19 patients with ACO of varying degrees and intraocular lenses of different materials. Digital slitlamp photographs were taken by 2 examiners using a standardized protocol. The intensity of anterior fibrosis was evaluated using subjective grading by 2 masked examiners and by image analysis. RESULTS: A standardized protocol was developed for documentation of ACO. The intraexaminer (or short-term) reproducibility (r = 0.96, P < .01) and interexaminer reproducibility (r = 0.93, P < .01) were excellent. The results of image analysis used to objectively quantify ACO correlated with the subjective grading (r = 0.95, P < .01). CONCLUSION: This standardized technique of slitlamp photography and image analysis provided reproducible documentation and can therefore serve as a basis for the quantification of ACO.

Anterior Chamber↗

PubMed2002

Effect of an acrylic intraocular lens with a sharp posterior optic edge on posterior capsule opacification.

PURPOSE: To compare the posterior capsule opacification (PCO) inhibiting effect of the sharp posterior optic edge design of the Sensar OptiEdge AR40e intraocular lens (IOL) (Allergan Surgical) with that of the round-edged design of the Sensar AR40 IOL. Setting Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: This prospective randomized patient- and examiner-masked study comprised 106 eyes of 53 patients with bilateral age-related cataract. Each patient had cataract surgery in both eyes and received an AR40 IOL in 1 eye and an AR40e IOL in the other eye. Postoperative examinations were at 1 week, 2 and 6 months, and 1 year. Digital slitlamp and digital retroillumination images of each eye were taken. The amount of PCO was assessed subjectively at the slitlamp and objectively using automated image-analysis software. RESULTS: The AR40e group had significantly less regeneratory and fibrotic PCO 1 year after surgery. The mean automated image-analysis software PCO score (scale 0 to 10) was 2.19 in the AR40 group and 1.10 in the AR40e group (P <.001). The AR40e group had less peripheral fibrotic PCO. There was no significant difference in patient-reported edge glare between the 2 IOL groups. CONCLUSIONS: The sharp-edged design of the Sensar OptiEdge AR40e IOL led to significantly less PCO than the round-edged AR40 IOL 1 year postoperatively.

Acrylic Resins↗