Biomedical subjects

Jens Funk

Publications and source records attributed to Jens Funk.

12 recordsLinked to original sources

PubMed2006

Dynamic contour tonometry (DCT) versus Goldmann applanation tonometry (GAT) - a comparison of agreement and reproducibility.

BACKGROUND: The PASCAL dynamic contour tonometer (DCT) is a novel device designed for intraocular pressure (IOP) measurements. It is assumed to be largely independent of corneal properties. In a previous study we compared DCT with Goldmann applanation tonometry (GAT) in 100 right eyes with normal corneas. The aim of the present study is to evaluate whether differences DCT-GAT >or= 2.0 mmHg found in the previous study are reproducible and also present in the fellow eye. METHODS: Twenty-three of the 100 patients (M:F = 8:15, mean age: 36 +/- 11 SD, range 22-53 years) with a previous difference DCT-GAT >or= 2.0 mmHg were included in the present study. The minimum interval between the initial and the current examination was 3 weeks. The IOP-values of the fellow eyes in this subgroup were assessed in parallel. RESULTS: The difference DCT-GAT was 2.44 +/- 0.4 SEM mmHg in the subgroup of the 23 right eyes and 2.03 +/- 0.5 SEM mmHg for the fellow eyes, compared to 0.94 +/- 0.5 SEM mmHg in the initial sample of 100 eyes. CONCLUSIONS: In cases with higher difference between DCT-GAT, the difference is reproducible and even present in the fellow eye. We, therefore, assume that the differences are not caused by chance, but by differing biomechanical corneal properties.

Adult↗

PubMed2006

Diagnostic accuracy of the Retinal Thickness Analyser: differentiation between normal eyes and eyes with glaucoma or macular pathologies.

BACKGROUND: The Retinal Thickness Analyser (RTA) is intended to detect glaucomatous changes as well as macular pathologies at the posterior pole. We determined the diagnostic accuracy for eyes with manifest glaucoma or macular diseases. METHODS: We examined 71 eyes with long-term, established eye conditions. Included were 28 eyes with glaucoma, 21 with different macular diseases and 22 normal eyes. All examinations were evaluated in a blind-test by RTA experts without any clinical information on the patients. After comparison of the RTA interpretation with the clinical diagnosis, we determined sensitivity, specificity, positive and negative predictive values. RESULTS: Of 71 examinations, 15 (21%) were not interpretable. If these results are excluded, the following diagnostic accuracy values were calculated for glaucoma and macular disorders respectively: sensitivity 75 and 59%, specificity 55 and 97%, positive predictive value 48 and 90% and negative predictive value 80 and 84%. These values were not significantly different when both eyes of each patient were included in the final analysis (n=133). CONCLUSION: The diagnostic values of the RTA determined in this case control study were not satisfactory. However, no clinical information was used in the assessment. The extent to which additional clinical information increases the diagnostic value remains to be determined.

Aged↗

PubMed2006

Pattern ERG as an early glaucoma indicator in ocular hypertension: a long-term, prospective study.

PURPOSE: The conversion rate from untreated ocular hypertension (OHT) to glaucoma is only approximately 1% per year. Discrimination of nonconverters and potential converters would help reserve preventative treatment for those who need it and thus avoid unnecessary side effects and expenditure for those who do not. This prospective study was designed to assess the pattern electroretinogram (PERG) as an early indicator of dysfunction preceding glaucoma. METHODS: Ninety-five eyes of 54 patients with intraocular pressure > or =25 mm Hg (or > or =23 mm Hg with additional risk factors), normal visual fields, normal optic disc cupping, and visual acuity > or =0.8 were evaluated. Every 6 months during a median follow-up of 8.2 years, the PERG and visual fields were obtained besides other standard diagnostics. PERGs were recorded in steady state mode in response to checkerboard stimuli at 15 reversals/s, and the amplitudes in response to check sizes of 0.8 degrees and 16 degrees as well as the ratio of the amplitude of responses to 0.8 degrees over that to 16 degrees checks were determined. RESULTS: Glaucomatous visual field defects developed in eight eyes. For the PERG to 0.8 degrees checks and for the PERG ratio, analysis of the receiver-operating characteristic (ROC) yielded steadily increasing ROC areas before conversion (i.e., an increasing ability of the PERG to predict nonconversion or conversion). One year before conversion, the ROC area of the PERG ratio was 0.78; at a threshold of 1.06 this corresponded to a sensitivity of 80% and a specificity of 71%. CONCLUSIONS: The PERG can help to predict stability or progression to glaucoma in OHT at least 1 year ahead of conversion.

Adult↗

PubMed2005

Excimer laser trabeculotomy: a new, minimally invasive procedure for patients with glaucoma.

BACKGROUND: Excimer laser trabeculotomy (ELT) ab interno is a new surgical technique to reduce intraocular pressure (IOP) in patients with glaucoma or ocular hypertension. Our purpose was to examine IOP reduction and the use of antiglaucoma drugs (AGD) in patients treated with ELT and to evaluate the safety of this laser treatment. METHODS: To increase the outflow of aqueous humor, ten microperforations of the trabecular meshwork were performed by an endoscope-guided photoablative laser probe (Excimer laser, AIDA, TUI-Laser, Munich; pulse energy: 1.2 mJ at fiber tip, pulse duration: 60 ns, repetition rate: 20 Hz). Average operation time usually was about 2 min. In our pilot study, one group of patients without cataract underwent ELT, the other group with cataract underwent phacoemulsification (PHACO) plus ELT. IOP, visual acuity, and AGD were determined preoperatively (T0) and 2-4 months (T1), 5-7 months (T2), 11-13 months (T3), and 22-26 (T4) months after surgery. Treatment was defined to be successful if (1) postoperative IOP was < or =21 mmHg, and (2) IOP reduction was at least 20%. RESULTS: ELT reduced the IOP from 24.1+/-0.7 (n=69) mmHg preoperatively to 18.8+/-0.4 (T1, n=66), 20.0+/-0.5 (T2, n=51), 18.8+/-0.8 (T3, n= 37), and 16.8+/-1.0 (T4, n=15) mmHg, respectively. However, 28% of the eyes needed repeat surgery due to insufficient IOP reduction. According to Kaplan-Meier statistics, the success rate was 60% (T1), 49% (T2), and 46% (T3), respectively. The number of AGD was 1.9+/-0.1 (T0), 1.2+/-0.2 (T1), 1.3+/-0.2 (T2), 1.8+/-0.2 (T3), and 1.5+/-0.3 (T4). Combined phacoemulsification plus ELT reduced the IOP from 22.4 mmHg+/-0.6 (T0, n=57) to 16.5+/-0.4 (T1, n=52), 16.1+/-0.5 (T2, n= 40), 16.4+/-0.4 (T3, n= 35), and 12.8+/-1.5 (T4, n=4) mmHg, respectively; 7% of the eyes treated with the combined procedure needed repeat surgery due to insufficient IOP reduction. According to Kaplan-Meier statistics, the success rate was 85% (T1), 74% (T2), and 66% (T3), respectively. The number of AGD was 1.1+/-0.2 (T0), 0.9+/-0.2 (T1), 1.1+/-0.2 (T2), 1.2+/-0.2 (T3), and 1.8+/-0.9 (T4). CONCLUSIONS: ELT, especially in combination with phacoemulsification, is a new, promising, minimally invasive laser treatment to reduce IOP for at least 1-2 years. ELT alone is less effective in IOP reduction.

Aged↗

PubMed2005

Ten-year results: detection of long-term progressive optic disc changes with confocal laser tomography.

BACKGROUND: The detection of a slowly progressive loss of optic nerve fibres in patients with ocular hypertension is a very important task for confocal laser tomography. We compared changes of the parameters of the Heidelberg Retina Tomograph (HRT) with changes of static visual field measurements. METHODS: Since 1994, patients with ocular hypertension have been monitored prospectively every 6 months with visual field measurements (Octopus 123, dG1x) as well as examinations of the optic disc using the HRT. A progressive excavation of the optic nerve head was defined as a significant increase or decrease of the linear regression over time. We analysed the HRT parameters cup area (CA), cup volume (CV), cup shape measure (CSM), rim volume (RV), retinal nerve fibre thickness (RNFLT) and contour height variation (CHV) each circular and for six different sectors of 109 eyes (60 patients). A glaucomatous visual field defect and therewith the conversion from ocular hypertension (OHT) to open angle glaucoma (OAG) was defined as reproducible defect-cluster >20 dB of two or three single points at the same location. RESULTS: Nine of 109 eyes converted from OHT to OAG. A significant linear increase of the circular parameters occurred in two (CA), four (CSM), two (CV) and a decrease in three (CHV), two (RV) and four (RNFLT) eyes. The sectoral analysis increased the results of CA and CV in the temporal superior and temporal inferior sectors (ts/ti): five/four (CA), two/three (CV). Cup shape measure showed in the temporal superior, temporal inferior (ti) and nasal inferior (ni) sectors slightly increased hits [five (ts), five (ti), five (ni)]. CONCLUSIONS: The linear model for the progression of the optic disc parameters detected only a small amount of the converters. The hit rate could be increased with the sectoral based analysis. Cup shape measure showed the highest rate.

Diagnostic Techniques, Ophthalmological↗

PubMed2005

Treatment of ocular hypertension and open angle glaucoma: meta-analysis of randomised controlled trials.

OBJECTIVE: Open angle glaucoma is one of the most common causes of blindness in industrialised nations. Treatments to lower ocular pressure are widely used in glaucoma prevention and treatment, despite conflicting evidence. DESIGN: We performed meta-analyses to reassess the effectiveness of pressure lowering treatment to delay the development of glaucoma in ocular hypertension, as well as progression of manifest open angle glaucoma. DATA SOURCES: Medline, Embase, and the Cochrane Library. SELECTION OF STUDIES: Eligible studies were randomised controlled trials with a concurrent untreated control group and information on time to glaucomatous changes to visual field and optic disc. Trial reports were reviewed independently by two investigators in an unblinded standardised manner. RESULTS: Meta-analysis of trials in ocular hypertension showed a significant preventive effect of reducing intraocular pressure on progression to glaucoma (hazard ratio 0.56, 95% confidence interval 0.39 to 0.81, P = 0.01; number needed to treat 12). Pooled data of studies in manifest glaucoma showed a significant delay of visual field deterioration (0.65, 0.49 to 0.87, P = 0.003; NNT = 7), with subgroup analysis showing a larger effect in patients with raised pressure and a reduced effect in normal tension glaucoma (subgroup comparison: not significant). CONCLUSIONS: Lowering intraocular pressure in patients with ocular hypertension or manifest glaucoma is beneficial in reducing the risk of visual field loss in the long term.

Glaucoma, Open-Angle↗

PubMed2005

Dynamic contour tonometry versus Goldmann applanation tonometry: a comparative study.

BACKGROUND: Various sources of error, including central corneal thickness (CCT) and structural corneal rigidity, have been proposed for Goldmann applanation tonometry (GAT). The Pascal dynamic contour tonometer (DCT) is a novel device designed for intraocular pressure (IOP) measurements assumed to be largely independent of CCT and corneal curvature. We compared DCT with GAT in eyes with normal corneas of various thickness. METHODS: We prospectively measured IOP using DCT and GAT in random order in 100 eyes of 100 subjects (M:F=46:54; mean age 42+/-19, range 23-88 years). RESULTS: Mean DCT values were about 1 mm Hg higher than GAT readings (16+/-3 vs 15+/-3 mmHg, p=0.001). Bland-Altman analysis of individual pairs of DCT and GAT measurements revealed a bias of -1.0 mmHg [95% confidence interval (CI): +/-1.2]. Neither GAT nor DCT showed a significant correlation with CCT (533+/-48, range 399-641 microm). CONCLUSIONS: In eyes with normal corneas, DCT allows suitable and reliable IOP measurements which are in good concordance with GAT. Comparison of DCT with intracameral manometry is desirable in the future.

Adult↗

PubMed2005

Combined cataract and glaucoma surgery: endoscope-controlled erbium:YAG-laser goniotomy versus trabeculectomy.

BACKGROUND: To compare endoscopic infrared laser trabecular ablation and trabeculectomy (both combined with cataract surgery) regarding intraocular pressure (IOP), visual acuity, anti-glaucomatous drugs and complications. METHODS: Seventeen eyes of 14 patients [age 74.7+/-11.7 years (arithmetic mean +/- standard deviation)]-13 with primary open-angle glaucoma (POAG) and four with pseudoexfoliation glaucoma (PEXG)-underwent standard cataract surgery. After lens implantation, a probe (1.1 mm external diameter) with optic and laser fibres and an irrigation tube was introduced through the cataract incision. To perforate Schlemm's canal, 15-17 single pulses (16 mJ, 160 micros) were applied using a photo-ablative infrared laser (Er:YAG, lambda=2.94 microm). All eyes except one received antiglaucoma treatment. The control group treated with cataract surgery and trabeculectomy consisted of 17 eyes (13 POAG, four PEXG) of 15 patients (age 75.0+/-5.6 years), each eye received antiglaucoma treatment. RESULTS: Mean follow-up was 3 years. The eyes treated with the endoscopic laser showed a mean preoperative IOP of 23.3+/-4.3 mmHg, which was reduced to 15.0+/-2.1 mmHg (mean IOP lowering 33.7%) after 3 years. Five eyes needed no medication for IOP-control after the procedure. Two eyes needed further surgery for IOP-control. In the control group, mean IOP was 24.5+/-2.6 mmHg in the beginning and 17.3+/-6.2 mmHg after 3 years, corresponding to a 33.3% lowering of IOP. Six eyes needed no medication, four eyes needed further surgery to lower IOP. CONCLUSIONS: After 3 years follow-up of a small pilot group, combined endoscopic infrared laser surgery with cataract surgery seems to be a safe and effective way to lower IOP. It shows the same ability to lower IOP as combined cataract surgery with trabeculectomy. In addition, there are markedly less complications with the endoscope-controlled photo-ablative laser procedure.

Aged↗

PubMed2003

Comparison of long-term fluctuations: laser scanning tomography versus automated perimetry.

BACKGROUND: The aim of our study was to investigate the long-term variability of laser scanning tomography and to compare it with the long-term variability of automated perimetry. METHOD: We retrospectively reviewed the charts of 199 patients (394 eyes) who underwent both automated perimetry (Octopus) and laser scanning tomography (Heidelberg retina tomograph, HRT) in our hospital since 1994. All patients either had ocular hypertension (OHT) or early stage glaucoma. The mean follow-up time was 5.4 years; the average number of examinations was 7.7. The variability was described by the variance ratio VR. RESULTS: The HRT parameters showed very similar long-term fluctuations as the Octopus parameters. In detail: VR of HRT parameters ranged from 0.04 (cup area, cup volume, mean cup depth) to 0.35 (contour height variation), whereas VR of Octopus parameters ranged from 0.12 (mean sensitivity) to 0.15 (loss variance). CONCLUSIONS: The long-term variability of HRT parameters is in the same range as the long-term variability of visual field parameters. Since it is now widely accepted that visual field changes over time should be reproduced at least once or twice before clinical consequences can be drawn, the same should be postulated for HRT changes over time.

Adolescent↗

PubMed2003

Endoscopically controlled erbium:YAG goniopuncture versus trabeculectomy: effect on intraocular pressure in combination with cataract surgery.

PURPOSE: . To compare the efficacy of endoscopic erbium:YAG laser goniopuncture in glaucoma treatment to trabeculectomy, both methods as adjuncts to cataract surgery. METHODS: . Fifty-nine eyes of 59 glaucoma patients with coexistent cataract were treated by phacoemulsification and endoscopic Er:YAG goniopuncture in a combined fashion. The primary study endpoints were intraocular pressure (IOP), number of antiglaucomatous drugs, postoperative complications, hospitalisation time and visual acuity at 1 year after surgery. To date, 24 eyes have finished the 1-year follow-up. This prospective treatment arm was compared to a retrospective inclusion-matched control group treated by trabeculectomy and cataract surgery in a single procedure. RESULTS: . In the laser-treated group, the mean IOP dropped by 30% from 23.4+/-3.7 mmHg to 16.3+/-6 mmHg ( P<0.0001) after 12 months. Without reoperation, treatment was successful in 71% of these eyes. In the control group, the IOP decreased by 33.5% from 22.7+/-3.3 mmHg to 15.1+/-3.8 mmHg ( P<0.0001). The success rate without reoperation was 46%. The number of antiglaucomatous drugs needed decreased from 1.48+/-0.95 to 0.48+/-0.7 ( P<0.0001) in the laser-treated group and from 2.0+/-0.9 to 0.39+/-0.6 ( P<0.0001) in the control group. Postoperative complications were found more frequently in the control group ( P<0.0001). Hospitalisation was shorter in the laser group ( P<0.0001). Postoperative visual acuity was lower in the control group ( P=0.004). CONCLUSION: . Combined Er:YAG goniopuncture and cataract surgery lowers the IOP to an extent comparable to combined trabeculectomy and cataract surgery. Due to fewer postoperative complications, Er:YAG goniopuncture seems to be superior to standard fistulation surgery as the primary approach within the first year.

Aged↗

PubMed2003

Combined endoscopic erbium:YAG laser goniopuncture and cataract surgery.

PURPOSE: To study the safety and efficacy of endoscopic erbium:YAG (Er:YAG) laser goniopuncture combined with cataract surgery to treat glaucoma. SETTING: Department of Ophthalmology, Albert-Ludwigs-University Freiburg, Freiburg, Germany, and Institute of Applied Physics, University of Bern, Bern, Switzerland. METHODS: In this nonrandominized clinical trial, 20 eyes of 20 patients with cataract and glaucoma were treated by combined phacoemulsification and Er:YAG goniopuncture. The primary study endpoints were intraocular pressure (IOP), visual acuity, and number of antiglaucoma drugs 1 year after surgery. Two- and 3-year postoperative data were also measured. This prospective treatment arm was compared to a retrospective inclusion-matched control group treated by cataract surgery alone. RESULTS: The mean IOP dropped by 30% (23.5 mm Hg +/- 3.9 [SD] to 16.3 +/- 2.7 mm Hg) after 12 months in the laser-treated group (P<.0001) and by 9% (19.8 +/- 1.3 mm Hg to 18.1 +/- 1.8 mm Hg) in the control group (P =.12). After 3 years, the mean IOP in the laser group was 15.0 +/- 2.0 mm Hg. The mean number of antiglaucoma drugs needed decreased from 1.6 +/- 0.9 to 0.5 +/- 0.8 in the laser group (P<.0001) and from 1.0 +/- 0.9 to 0.8 +/- 0.9 in the control group (P =.21). Anterior chamber hemorrhage occurred in 12 eyes after laser treatment and resolved within 72 hours in all but 1 patient who was on warfarin sodium (Coumadin) therapy. There were no cases of hypotony in either group. CONCLUSIONS: Endoscopic Er:YAG laser goniopuncture was a successful adjunct to cataract surgery in glaucoma patients. Sustained IOP reduction was achieved with few postoperative complications.

Aged↗

PubMed2002

[Flicker comparison of optic disc photographs: sensitivity and specificity].

BACKGROUND: Examination and documentation of the optic nerve head are essential in monitoring glaucoma patients. Even minor changes in optic nerve head morphology can be visualised using the so-called flicker test: Two optic nerve head photographs, taken at consecutive examinations, are superimposed by projection. When occluding the pictures in a rapid alternating fashion, changes in optic nerve head morphology appear as motion. In this study, we evaluated sensitivity and specificity of the flicker test. METHOD: A set of 33 pairs of serial optic disc slides was used as gold standard. These 33 pairs had been classified earlier by 3 independent groups of experts. 23 had been classified as "no change over time", 10 had been classified as "change". All 33 pairs were now evaluated by flicker comparison in a masked fashion. RESULTS: Flicker comparison usually took 1 minute per pair of slides. Sensitivity was 90 %, specificity was 65 %. CONCLUSION: The sensitivity was reasonably high. The moderate specificity was due to some cases showing "change" with the flicker comparison which might have been overlooked by the expert groups. Flicker comparison is an easy, fast and reliable technique to evaluate pairs of consecutive optic disc photographs.

Disease Progression↗