Search PubMed⌕ Search

Biomedical subjects

Niels Ehlers

Publications and source records attributed to Niels Ehlers.

At least 19 recordsLinked to original sources
PubMed2006

Visual outcome, local tumour control, and eye preservation after 106Ru/Rh brachytherapy for choroidal melanoma.

To study the visual outcome, local tumour control, and eye preservation 5 years after ruthenium/rhodium 106 brachytherapy for choroidal melanoma. The study included 55 consecutive patients treated by 106Ru/Rh brachytherapy for a choroidal melanoma during the period 1988-2000 and followed through 2004. The 5-year probability for not losing at least 5 Snellen lines was 59% (n = 45), for retaining a visual acuity of 0.33 or better was 28% (n = 34), and for retaining better than 0.1 was 40% (n = 45). The 5-year probability for no local recurrence was 73% and for eye preservation 72% (n = 55). 106Ru/Rh brachytherapy for choroidal melanoma resulted in a clinically significant vision loss, no local recurrence, and eye preservation in most patients after 5 years. 106Ru/Rh brachytherapy can be regarded as a good treatment option for small and medium-sized tumours but not for large tumours.

Adult↗
PubMed2006

Simultaneous quantification of 17 immune mediators in aqueous humour from patients with corneal rejection.

PURPOSE: To simultaneously quantitate and compare the concentrations of 17 immune mediators: (1) the cytokines interleukin-1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-10, IL-12p70, IL-13, IL-17, tumour necrosis factor-alpha, interferon-gamma; (2) the growth factors granulocyte-monocyte colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF), and (3) the chemokines CXCL-8, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1beta in aqueous humour from patients with corneal rejection and patients with a non-inflammatory condition in the anterior chamber. METHODS: Aqueous humour was obtained by paracentesis of the anterior chamber in 14 patients with corneal rejection, three patients with cataract and six patients with Fuchs' endothelial dystrophy. Simultaneous quantitation of 17 mediators in 25 micro l aqueous humour from each patient was performed by employing a highly sensitive Luminex 100 multiplex array assay. RESULTS: All 17 immune mediators were detected in aqueous humour from rejection patients. The ranges of the immune mediators were determined. The immune mediators were significantly increased in aqueous humour from rejection patients compared with that from other patients. CONCLUSIONS: The Luminex 100 multiplex array assay is very efficient in simultaneous quantitation of multiple immune mediators in small volumes of aqueous humour. A total of 17 immune mediators were increased in aqueous humour from rejection patients. This underlines the complex immunological interactions of the rejection process.

Adult↗
PubMed2005

[Efficacy and safety of laser-assisted in situ keratomileusis for myopia].

INTRODUCTION: The aim of this study was to assess the efficacy, frequency of re-operation and type and frequency of complications after laser-assisted in situ keratomileusis (LASIK) treatment for moderate to high levels of myopia. MATERIALS AND METHODS: 357 eyes from 190 patients were reviewed. The mean of the preoperative correction was -8.38 D (-1.75; -16 D) sph. (spherical), -1.00 D (0; 4.5 D) astigmatism. 15% (55 eyes) were re-treated. The mean of the correction before re-treatment was -2.78 D (+2.25; -11.00 D) sph., -0.43 D (0; -2.00 D) astigmatism. RESULTS: The three-month follow-up rate was 96% for primarily treated eyes and 99% for re-treated eyes. Where full correction was intended, 53% of the primarily treated and 93% of the re-treated eyes achieved an uncorrected visual acuity of > or =0.5. The refractive error for myopia less than -8 D was -0.80 D +/- 0.83 D and -1.37 D +/- 1.33 D for myopia -8 D and above after one treatment and -0.47 +/- 0.66 D after re-treatment. 1.2% (4) of the primarily treated and 3.9% (2) of the retreated eyes lost more than two lines in best spectacle-corrected visual acuity (BCVA). CONCLUSION: LASIK treatment for moderate to high levels of myopia leads in all cases to a reduced degree of myopia. There is a significant degree of unreliability on the accuracy of the treatment with a tendency to under correction. Postoperatively, many patients still have to use correction for distance vision. Significant loss of visual acuity occurs infrequently.

Adult↗
PubMed2005

Proteome profiling of corneal epithelium and identification of marker proteins for keratoconus, a pilot study.

The purpose of this study is to identify corneal proteins differentially expressed between keratoconus and normal epithelial samples. Proteins from the corneal epithelium were isolated from 6 keratoconus and 6 myopia patients (controls) and separated by 2D-gel electrophoresis. Six % and 12% SDS-PAGE gels were used to separate low and high molecular weight proteins. Gels were silver stained and protein spots were defined by Melanie II software. The proteins that were most altered in expression comparing keratoconus and controls were extracted, trypsin-digested, and identified by mass spectroscopy. Approximately 200-500 protein spots were detected on each gel. Nineteen spots were identified as differentially expressed between keratoconus and reference epithelium including cytokeratin 3 (< 7.8 fold), gelsolin (1.6 fold), S100A4 (1.9 fold), and enolase 1 (0.72 fold). Another identified protein found at very high levels was cytokeratin 12. Gelsolin, cytokeratin 3, and cytokeratin 12 have previously been described to be involved in other corneal diseases. Three proteins, gelsolin, alpha enolase, and S100A4 were identified to be differentially expressed in keratoconus compared to reference epithelium and thus may be involved in the pathogenesis.

Biomarkers↗
PubMed2005

Corneal power, thickness, and stiffness: results of a prospective randomized controlled trial of PRK and LASIK for myopia.

PURPOSE: To compare the short-, medium-, and long-term changes in corneal optical power and corneal aberrations, central corneal thickness, and corneal "stiffness" assessed by pneumotonometry readings in patients having laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) for myopia. SETTING: Department of Ophthalmology, Arhus University Hospital, Arhus, Denmark. METHODS: One eye of each of 45 patients with myopia ranging from -6.00 to -8.00 diopters (D) (spherical equivalent spectacle refraction [SER]) was randomized to LASIK (n=25; mean SER -7.12 D +/- 0.57 [SD]) or PRK (n=20; mean SER -6.91 +/- 0.57 D). Data were collected prospectively before and 1, 3, 6, 12, and 36 months after surgery. Measurements included corneal topography (TMS-1, Tomey), corneal thickness (ultrasound pachymetry), and apparent intraocular pressure (IOP) (pneumotonometry). Retreatments were not performed during the first year, and retreated eyes were excluded from the 3-year follow-up. Changes in corneal power and aberrations, thickness, and apparent IOP were calculated in a pair-wise manner for 3 time periods: short term (preoperative to 1 month after surgery), medium term (1 to 12 months after surgery), and long term (1 to 3 years after surgery). RESULTS: In the short term, corneal power decreased equally in LASIK and PRK eyes. Spherical aberrations and coma-like aberrations increased equally, while corneal thickness decreased significantly less in LASIK eyes than in PRK eyes. The apparent IOP decreased more in LASIK eyes than in PRK eyes. In the medium term, corneal power increased significantly in both groups. Spherical aberrations decreased significantly in PRK eyes but not in LASIK eyes. From 1 to 12 months, corneal thickness increased more in PRK eyes than in LASIK eyes. During this period, the apparent IOP increased significantly in LASIK eyes. In the long term, corneal power and corneal aberrations did not change significantly in either group. Corneal thickness increased slightly but significantly in both groups. The apparent IOP increased significantly more in PRK eyes. CONCLUSIONS: Differences between LASIK and PRK related to time-dependent events affecting corneal shape and structural integrity were present. Peripheral changes in flap hydration in LASIK eyes and epithelial and/or stromal thickening in PRK eyes appeared to be the most important factors in optical power changes in the first year after treatment. The changes in apparent IOP suggest that some interlamellar healing occurred during the first year after LASIK. After LASIK and PRK, corneal bending stiffness seemed permanently decreased, although some restiffening may occur in PRK eyes in the long term.

Adult↗
PubMed2005

Altered expression of CLC, DSG3, EMP3, S100A2, and SLPI in corneal epithelium from keratoconus patients.

PURPOSE: This investigation was designed to determine whether the five genes, CLC, DSG3, EMP3, S100A2 and SLPI, are differentially expressed in keratoconus, as indicated from another study. METHODS: Gene expression was monitored using quantitative real-time PCR on 14 keratoconus samples and 16 controls, and normalized to GAPDH and B2M. The DSG3, S100A2, and SLPI proteins were quantified by Western blotting, and the cellular localization was determined by immunohistochemistry. One of the genes, CLC, was reduced in gene expression and its four exons were sequenced. RESULTS: The five genes were all differentially expressed in keratoconus (P < 0.04) and so were at least three of the encoded proteins (P = 0.009). DSG3 was expressed in association with the cell membrane of the basal and suprabasal epithelial cells, and S100A2 was expressed in the nucleus and cytoplasm, often as intracellular granules. Two SNPs (rs374185 and rs384138) were observed in the CLC gene, each with an allele frequency of 68%. No other mutations were detected. CONCLUSIONS: The five genes, and three of the encoded proteins, were shown differentially expressed between a group of keratoconus patients and a reference group using different techniques. These alterations, in combination with earlier findings, strongly demonstrate the genes to be involved in the corneal disease. We suggest the unambiguously expressed DSG3 protein to be used as a marker for keratoconus.

Biomarkers↗
PubMed2005

Proteomic analysis of aqueous humour from patients with acute corneal rejection.

PURPOSE: To compare the basic proteomic composition of aqueous humour (AH) from patients with corneal rejection (patients) with AH from patients with cataract (controls). METHODS: Aqueous humour was analysed for total protein concentration using Bradford's method and for protein composition using two-dimensional (2D) gel electrophoresis. Image analysis was used to detect protein spots in 2D gels that were increased by more than factor 2 in patients as compared with controls. Increased spots were identified by immunoblotting and mass spectrometry. RESULTS: Aqueous humour from patients contained significantly higher total protein concentration than did AH from controls. A total of 31 spots were significantly increased in 2D gels from patients. The spots were derived from albumin, alpha1-antitrypsin, apolipoprotein J, cytokeratin type II, serin proteinase inhibitor and transthyretin. After correction of spot volumes by total protein concentrations, 10 spots derived from albumin, cytokeratin type II and alpha1-antitrypsin remained significantly increased. CONCLUSION: The proteomic composition of AH differed significantly between patients and controls. The identified proteins suggest that the changes in AH are due to at least three different mechanisms: breakdown of the aqueous-blood barrier, enzymatic degradation, and liberation of locally synthesized proteins.

Aged↗
PubMed2005

Soluble CD163 and interleukin-6 are increased in aqueous humour from patients with endothelial rejection of corneal grafts.

PURPOSE: To evaluate soluble CD163 (sCD163) as a new marker of macrophage activity in aqueous humour from patients with corneal rejection and to investigate correlations between sCD163, the CD163 inducing interleukin-6 (IL-6), and albumin; to investigate whether increases in sCD163 and IL-6 levels in aqueous humour were results of intra- or extraocular production, and to investigate the impact of sCD163 and IL-6 levels on graft outcome. METHODS: Aqueous humour was obtained from 19 patients with endothelial rejection of corneal grafts, seven cataract patients and five cataract patients with uncomplicated corneal grafts. The presence of sCD163 was investigated by immunoprecipitation and immunoblotting. The concentrations of sCD163, IL-6 and albumin were measured by ELISA. RESULTS: Soluble CD163 was detected in aqueous humour from patients with corneal rejection. Soluble CD163, IL-6 and albumin were significantly increased in aqueous humour from patients with corneal rejection when compared with control patients. When normalizing sCD163 and IL-6 with albumin, the differences between rejection patients and control groups became insignificant for sCD163 but remained significant for IL-6. Neither IL-6 nor sCD163 were related to the outcome of the corneal rejection. CONCLUSIONS: Both sCD163 and IL-6 are present in high levels in aqueous humour from patients with rejection of corneal grafts. Our data suggest that IL-6 is produced locally, whereas sCD163 is at least partly derived from influx from plasma.

Adult↗
PubMed2005

Alpha-1--antitrypsin in aqueous humour from patients with corneal allograft rejection.

PURPOSE: To investigate the presence and concentration of alpha1-antitrypsin in aqueous humour at the time of corneal rejection and to compare results obtained from patients with reversible and irreversible rejection. METHODS: Samples of aqueous humour were obtained from 17 patients with acute corneal endothelial allograft rejection. The presence of alpha1-antitrypsin in aqueous humour was confirmed by immunoblotting and measured employing a sandwich ELISA. Total protein concentrations in aqueous humour were measured using Bradford's method. The outcome of corneal rejection episodes was determined 1 month after diagnosing corneal rejection and described as reversible or irreversible rejection. RESULTS: alpha1-antitrypsin was detected in aqueous humour. Patients with reversible rejection had significantly higher alpha1-antitrypsin concentration than patients with irreversible rejection (p = 0.044). There was no significant difference in total protein concentrations (p = 0.745), and no correlation was found between alpha1-antitrypsin and total protein concentrations (p = 0.368). CONCLUSIONS: alpha1-antitrypsin in aqueous humour seems to signal a favourable outcome of corneal rejection. The possible mechanism is discussed.

Acute Disease↗
PubMed2005

Central corneal thickness in high myopia.

PURPOSE: To examine if central corneal thickness (CCT) is different in emmetropia and high myopia. METHODS: 57 emmetropic subjects (0 to + 1.5 D) and 48 high myopes (all more than - 6 D in spherical equivalent refraction) were studied. CCT was measured by a Haag-Streit Optical Low-Coherence Reflectometry (OLCR) pachymeter, a recently developed high precision pachymeter with a standard deviation (SD) for repeated measurements of 1 microm. RESULTS: Mean CCT for the emmetropic group was 538.6 microm (SD = 32.1), and for the myopic group 527.7 microm (SD = 35.0). Neither the mean CCT nor the variance from the two groups showed a statistically significant different (p > 0.05). CONCLUSION: CCT is not systematically altered in myopia. The process by which the myopia progresses does not to a measurable degree influence the central cornea.

Adolescent↗
PubMed2004

Corneal thickness: measurement and implications.

The thickness of the cornea was reported in more than 100-year-old textbooks on physiological optics (Helmholtz, Gullstrand). Physiological interest was revived in the 1950s by David Maurice, and over the next 50 years, this 'simple' biological parameter has been studied extensively. Several techniques for its measurement have been described and physiological and clinical significance have been studied. In this review, the different methods and techniques of measurement are briefly presented (optical, ultrasound). While the corneal thickness of many animals are the same over a considerable part of the surface, in the human cornea anterior and posterior curvature are not concentric giving rise to a problem of definition. Based on this the precision and accuracy of determining the central corneal thickness are discussed. Changes in corneal thickness reflects changes in function of the boundary layers, in particular the endothelial barrier. The absolute value of thickness is of importance for the estimation of IOP but also in diagnosis of corneal and systemic disorders. Finally it is discussed to what extent the thickness is a biometric parameter of significance, e.g. in the progression of myopia or in the development of retinal detachment.

Cornea↗
PubMed2004

Pupil size and night vision disturbances after LASIK for myopia.

PURPOSE: To examine whether standardized, preoperative evaluation of pupil sizes can predict the risk of night vision visual disturbances after bilateral laser in situ keratomileusis (LASIK) for myopia. METHODS: A prospective study was carried out involving 46 patients who underwent bilateral LASIK for myopia. Pupil sizes were measured before surgery using an infrared pupillometer under standardized settings. Pre- and postoperative refraction and best spectacle-corrected visual acuity (BSCVA) were registered. At the 3-month follow-up visit, the patients completed a questionnaire regarding night vision pre- and postoperatively. RESULTS: The mean bilateral, spherical equivalent refraction (SE) was - 8.76 D (range 6.32 to - 12.0 D) preoperatively, and - 1.69 D (range 0 to - 4.38 D) postoperatively. The mean bilateral BSCVA was not changed by the operations. We found a significant correlation between large scotopic pupil sizes and the impression of worsened night vision (p < 0.01). A significant correlation between gender (males) and subjectively reduced night vision postoperatively was also found (p < 0.05). CONCLUSION: Large pupil size measured preoperatively is correlated with an increased frequency of subjectively experienced post-LASIK visual disturbances during scotopic conditions. We recommend preoperative evaluation of pupil size in all patients prior to LASIK surgery.

Adult↗
PubMed2004

Are cataract and iris atrophy toxic complications of medical treatment of acanthamoeba keratitis?

PURPOSE: Two cases of acanthamoeba keratitis with almost identical clinical courses developed mature cataract and iris atrophy after prolonged treatment with chlorhexidine 0.02% and propamidine isethionate 0.1%. It is suggested that these complications were caused by the chemicals, rather than resulting from the amoebae-induced inflammation. METHODS: Penetrating keratoplasty was performed in both cases when perforation from peripheral ulceration was threatening. RESULTS AND CONCLUSIONS: The immediate results were good. From these two cases it seems possible that there is a maximum level of intensity of the medical treatment and also that surgery should be considered at an earlier stage, before intraocular complications develop.

Acanthamoeba Keratitis↗
PubMed2004

Primary corneal myxoma.

PURPOSE: To present the clinical and histopathological characteristics of a corneal myxoma. METHODS: A 36-year-old, white woman presented with blurred vision and a whitish opacity on the left cornea. Clinical examination revealed a whitish, non-tender, 5 x 9 mm superficial tumour on the cornea. The tumour was excised and examined microscopically. RESULTS: The tumour was composed of spindle-shaped cells in a myxomatous ground substance. Immunohistochemically, the tumour cells were positive for vimentin, muscle-specific antigen and smooth muscle antigen. The tumour was classified as a myxoma of the cornea. The origin of the tumour is discussed. CONCLUSION: This is the second reported case of a corneal myxoma without prior corneal disease.

Adult↗