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Biomedical subjects

N Eter

Publications and source records attributed to N Eter.

At least 19 recordsLinked to original sources

[Intravitreal bevacizumab for neovascular age-related macular degeneration].

The efficacy and safety of the therapeutic anti-VEGF concept has already been demonstrated for pegaptanib and ranibizumab. Bevacizumab acts as an antibody against all VEGF-A isoforms and has been developed for oncological indications with intravenous application. Initial reports on intravitreal administration in patients with neovascular age-related macular disease (AMD) have shown beneficial morphological and functional effects. In the meantime, bevacizumab has been used off-label in thousands of patients with AMD. However, data from prospective, controlled, randomized trials on both safety and efficacy are lacking. Herein recent experiences with bevacizumab are summarized and discussed. Furthermore, a web-based platform for online data registration and pooled analyses is presented.

Angiogenesis Inhibitors↗

[Cataract surgery in cases of age-related macular degeneration].

It has been noted for some time that cataract surgery in the presence of retinal comorbidity such as diabetic macular edema may generate a progression of macular changes and result in a poor visual outcome. Recent findings show that adverse events may also occur in the presence of age-related macular degeneration (AMD). Therefore, when indicating cataract surgery the surgeon needs to consider the risks both for progression of early into late stages of AMD or further deterioration of late manifestations of AMD. Furthermore, in the presence of advanced atrophic or neovascular AMD the question arises whether or not the patient may benefit from cataract surgery in spite of an already existing central visual loss. Here we critically review results from recent studies.

Cataract Extraction↗

[Variations in intraocular pressure (IOP) and necessity for paracentesis following intravitreal triamcinolone injection].

BACKGROUND: Intravitreal triamcinolone injection (IVT) has become a treatment option for macular edema of heterogeneous etiology and neovascular retinal diseases including AMD. Besides the risk for a steroid-induced secondary open-angle glaucoma, the acute rise in intravitreal volume induces IOP elevations immediately after injection. To decrease the intravitreal volume a paracentesis is advocated by many surgeons. The aim of this study was to determine variations in IOP at different time points immediately after IVT in order to assess the necessity for routine paracentesis. METHODS: The IOP was recorded by Goldmann applanation tonometry preoperatively, 10 minutes, 1, 3 and 24 hours after intravitreal injection of 0.1 mL (4 mg) triamcinolone. A consecutive series of 32 eyes of 32 patients with diabetic macular edema, diffuse edema after central vein occlusion or occult subfoveal choroidal neovascularization due to age-related macular degeneration was included. Statistical analysis was performed with ANOVA test and Bonferroni correction. RESULTS: Compared to baseline (15.24 +/- 0.52 mm Hg) IOP was significantly elevated 10 min postoperatively (22.28 +/- 1.4 mmHg; p < 0.05). One hour after injection IOP decreased to 15.58 +/- 0.69 mmHg (p < 0.05). Three and 24 h after injection mean IOP was not significantly different from preoperative baseline levels. Immediately after IVT light perception was tested and retinal perfusion was evaluated by indirect ophthalmoscopy. In none of the patients was a paracentesis necessary. CONCLUSION: Intravitreal injection of 0.1 mL triamcinolone led to a moderate transient rise in IOP. Based on these results, a routinely performed paracentesis immediately before or after IVT is not required. As paracentesis bears an additional risk including endophthalmitis it should only be considered if functional testing following injection indicates a relevant impairment of retinal perfusion.

Aged↗

Lower limits of fluorescein and indocyanine green dye for digital cSLO fluorescence angiography.

BACKGROUND: With the advent of digital confocal scanning laser ophthalmoscopy it is possible to detect low levels of fluorescence. Here we used a novel confocal scanning laser ophthalmoscope (cSLO) to determine lower limits of dye required for fluorescein (FL) and indocyanine green (ICG) angiography. METHODS: A cSLO (Heidelberg retina angiograph 2, Heidelberg Engineering, Dossenheim, Germany) with an optically pumped solid state laser (488 nm) for FL and a diode laser (790 nm) for ICG angiography (FL/ICG-A) was used. 62 FL-As were performed in 53 patients and 45 ICG-As were performed in 39 patients with neovascular age related macular degeneration. The volume and overall dye content of bolus injections was gradually tapered (FL: 500 mg, 250 mg, 200 mg, 166 mg, 100 mg; ICG: 25 mg, 20 mg, 15 mg, 10 mg, 5 mg, 2.5 mg), while dye concentrations were kept constant at 100 mg/ml for FL and at 5 mg/ml for ICG. Images were obtained 1, 5, 15, and 30 minutes after dye injection. Image quality was evaluated by two independent readers using standardised criteria. RESULTS: For amounts down to 166 mg for FL and to 5 mg for ICG, sufficient image quality was achieved during all phases following injection. Only late phase images showed less contrast compared to typically used dye amounts, which was irrelevant for interpretation and clinical management. CONCLUSIONS: With the increased sensitivity of this novel cSLO system, amounts of injected dye during FL-A can be reduced to one third for FL and to one fifth for ICG without relevant loss of image quality or information compared to conventionally used dye levels. These amounts can be used for routine angiography and allow relevant savings for units performing FL-A.

Aged↗

[OCT in age-related macular degeneration. Findings, usage in clinical routine, and assessment of treatment outcome].

Optical coherence tomography (OCT) represents a fast and noninvasive examination technique that generates two-dimensional sections of the posterior pole in vivo. Although this method is now widely applied in the diagnosis of various heterogeneous macular diseases, its role in patients with age-related macular degeneration (AMD) is less well established. OCT allows for quantitative as well as qualitative assessment of various AMD phenotypes. Qualitative assessment comprises the evaluation of intra- or subretinal fluid, intraretinal cystoid spaces, and retinal pigment epithelial detachments. However, together with the clinical findings and fluorescence angiography, it can provide useful additional information including monitoring of treatment effects.

Aging↗

[Interval reduction of photodynamic therapy (PDT) in age-related macular degeneration (AMD) is not advantageous. A pilot project].

PURPOSE: To find out if carrying out PDT again 6 weeks after initial PDT will improve the results at 3 months. METHODS: A total of 22 eyes were treated according to the dose regimen proposed by the TAP study. RESULTS: After the first PDT, the CNV remained permanently closed in 14% of the eyes. Repeating the treatment 6 weeks later did not lead to permanent closure of more CNVs or a diminished size at 3 months. Short-term re-treatment had no substantial effect on the underlying choriocapillaries. Visual acuity did not profit or suffer from early re-treatment. CONCLUSION: Shortening of the treatment interval has no serious side-effects, but does not seem to improve the results reported in the TAP study.

Choroidal Neovascularization↗

Magnetic resonance imaging analysis of anterior and posterior eye segment displacement during ocular gaze shifts.

PURPOSE: To determine the relationship between movements of the posterior and anterior eye segments during arbitrary gaze shifts and to obtain information for monitoring fixation during radiotherapy for ocular diseases. METHODS: We examined eye movements of ten emmetropic volunteers in a 1.5 T magnetic resonance system. Using a T2-weighted ultrafast turbo-spin echo sequence (UTSE), the eyes were examined within 21 seconds. Sagittal and transversal eye slices were obtained in five passages in five gaze directions (straight ahead, 15 degrees above, 15 degrees below, 15 degrees right and 15 degrees left of the primary position). Displacement of the posterior eye segment was analyzed in relation to the movement of the anterior segment in all directions. RESULTS: The relationship between the movements of the anterior and posterior eye segment was 1:0.8 (+/- 0.06 SD) during horizontal gaze shifts and 1:1.16 (+/- 0.11 SD) during vertical gaze shifts. CONCLUSIONS: Magnetic resonance imaging showed that the relationship between anterior and posterior eye segments was different during horizontal and vertical eye movements, indicating the presence of more than one center of rotation. Compared to the anterior eye segment, there was less displacement of the posterior eye segment during horizontal eye movements and more displacement during vertical eye movements.

Adult↗

Short-term reaction of choroidal neovascularization and choriocapillaris to photodynamic therapy in age-related macular degeneration.

PURPOSE: To identify the number of primary angiographic nonresponders to photodynamic therapy (PDT) with verteporfin, to determine the rate and speed of reperfusion of choroidal neovascularization (CNV) within a short observation period of only 5 weeks, and to examine the reaction of the underlying choroidal vessels. METHODS: PDT according to the TAP regimen was carried out in 36 eyes with subfoveal classic CNV secondary to age-related macular degeneration. The response to PDT was examined 1 (T1) and 5 (T2) weeks following treatment. At all visits distant visual acuity was measured and both fluorescein and indocyanine green angiography was carried out. RESULTS: One week after treatment (T1), complete closure of classic CNV had not been achieved in 17% of eyes (primary angiographic nonresponders). At T2, 91% of eyes showed reperfusion of the CNV. In 83% of the primary angiographic nonresponders the CNV size was larger than before treatment. Choroidal shadowing was present in 82% at T1 and in 48% at T2. CONCLUSIONS: Primary angiographic PDT nonresponders are relatively rare; however, in contrast to former reports, they exist and can be identified by follow-up examination 1 week after PDT. Recurrence of leakage occurred earlier than expected and may require closer follow-up and earlier retreatment than recommended by the TAP trial.

Angiography↗

DMSO mimics inhibitory effect of thalidomide on choriocapillary endothelial cell proliferation in culture.

AIM: To evaluate the effect of thalidomide on bovine choriocapillary endothelial cell proliferation. METHODS: Posterior segments of bovine eyes were incubated with trypsin. After digestion of the tapetum, pieces of Bruch's membrane with the adherent choriocapillaris were scraped, digested again with a cocktail of enzymes, washed and cultured in MCDB 131 medium. Cells were incubated with 100 micro g/ml thalidomide (dissolved in DMSO as recommended). Control cultures were incubated with DMSO alone or without any supplement. Cell proliferation after 24 hours was determined in a counting chamber. Purity of the cultures was controlled by immunohistochemical staining and labelling with low density lipoprotein. RESULTS: Thalidomide dissolved in DMSO inhibited proliferation of choriocapillary endothelial cells compared to control cultures incubated without any supplement. However, DMSO alone suppressed cell proliferation equally well. CONCLUSION: In cultured bovine choriocapillary cells the inhibiting effect of thalidomide may at least in part be attributed to the solvent DMSO alone.

Angiogenesis Inhibitors↗

A new technique for tear film fluorophotometry.

AIM: To develop a reliable and objective non-touch technique for determination of tear volume and tear secretion by means of tear film fluorophotometry. METHODS: 10 defined concentrations of sodium fluorescein were given in an artificial chamber and measured by the Fluorotron Master (Coherent Radiation Inc). A calibration line was established and the calibration equation was programmed into the Fluorotron Master computer software. In 28 patients (56 eyes) with dry eye symptoms and 15 volunteers (30 eyes) tear volume and tear secretion were then measured directly without taking a tear sample, using the new technique. RESULTS: The values obtained by the Fluorotron Master measuring 10 defined fluorescein concentrations within an artificial chamber are approximately 100 times lower than the actual concentrations. The calibration line led to a calibration equation: y = 36 + 0.01 x X. The mean tear secretion in 56 eyes of patients with dry eye symptoms was 2.48 microl/min, compared to 3.4 microl/min in healthy volunteers. The difference was statistically significant. Average tear volume was 7.0 microl in patients and 7.2 microl in healthy volunteers with no statistically significant difference. CONCLUSION: The method developed is a simple and reliable non-touch technique without the need for taking a tear sample, which makes the examination faster and more comfortable for the patient.

Adult↗

External beam radiotherapy for age-related macular degeneration causes transient objective changes in tear-film function.

PURPOSE: Dry-eye symptoms have been described as possible radiation side effects after external beam radiotherapy for age-related macular degeneration. We therefore investigated tear-film function before and after treatment. METHODS: Thirty-nine patients with no apparent history of dry-eye symptoms were treated with a 6 MV linear accelerator using a 2x2 cm lateral field angled 10 degrees posteriorly. A total dose of 20 Gy, divided into 10 fractions of 2 Gy and administered 3 times a week, was delivered. Before and 1, 3, and 6 months after radiotherapy, tear secretion was measured by means of tear-film fluorophotometry. The fellow eyes served as controls. RESULTS: At baseline, mean tear secretion as measured by tear-film fluorophotometry was 7.15 microl/min in the eyes receiving radiation and 5.89 microl/min in the control eyes. No statistically significant differences were found between the two eyes at baseline (signed rank test). One month after treatment, again no significant differences could be found between the two eyes; 3 months after radiation, however, tear secretion was significantly lower in the irradiated eyes than in the fellow eyes (P=0.0017). Six months after treatment this effect could no longer be detected. CONCLUSION: External beam radiotherapy using 20 Gy in 10 fractions and a 2x2 cm lateral field causes a statistically significant difference in tear secretion 3 months after radiation. This effect seems to be transient, as it had disappeared in later follow-up examinations.

Dose Fractionation, Radiation↗

Typical ocular findings in a patient with multiple endocrine neoplasia type 2b syndrome.

BACKGROUND: Multiple endocrine neoplasia (MEN) type 2b syndrome is accompanied by typical ocular findings; however, the disease is often only diagnosed at an advanced stage by symptoms of C-cell carcinoma or pheochromocytoma and is then fatal in most cases. Therefore, the importance of ophthalmic assessment in making the diagnosis has to be stressed. METHODS: The history and ocular findings of a patient with MEN 2b syndrome are described, and a brief overview of the syndrome is given. RESULTS: Slit-lamp examination showed extremely thickened corneal nerves as well as multiple small plexiform and nodular subconjunctival tumors. Both eyes also displayed thickened upper and lower eyelids. A molecular genetic study of the RET proto-oncogene showed a heterozygous ATG to ACG mutation in codon 918 of exon 16. CONCLUSION: Greatly thickened corneal nerves and subconjunctival tumors may be the first hint of MEN 2b. Whenever greatly thickened corneal nerves are detected, MEN 2b must be ruled out.

Adrenal Gland Neoplasms↗

Radiotherapy for age-related macular degeneration: is there a benefit for classic CNV?

AIM: To evaluate the efficacy of radiotherapy in the treatment of subfoveal classic and occult choroidal neovascularization (CNV) in age-related macular degeneration (AMD) under strict fixation control. METHODS: Twenty-seven eyes of 27 patients with subfoveal CNV as a result of AMD were treated with a total dose of 20 Gy in 10 fractions (10 well-defined, 17 occult). Fixation monitoring was achieved by installing a TV camera with an attached fixation light 3 cm from the cornea of the eye being treated. Visual acuity and fluorescein angiography were obtained before and 6 months after treatment. Fifteen eyes of 15 patients served as controls (4 well-defined, 11 occult). RESULTS: After 6 months the treated group showed an average decrease in visual acuity of 27%; the control group experienced a decrease of 31%. Membrane size increased by 56% in the treated group and by 28% in the control group. There was no statistically significant difference. Within the subgroup analysis, however, patients with classic CNV suffered significantly less visual loss than in the control group. CONCLUSION: Radiation therapy under optimized treatment conditions by fixation monitoring failed to control further growth in membrane size in both classic and occult CNV. Regarding visual acuity, however, patients with classic CNV seem to benefit from radiation treatment compared to the natural course.

Adolescent↗

Long-term results of pneumatic retinopexy.

PURPOSE: To evaluate the long-term outcome (>6 years) of retinal reattachment by pneumatic retinopexy. METHODS: Seventy-eight eyes were examined retrospectively after treatment of a retinal detachment with pneumatic retinopexy. The average follow-up period was 6.35 years. The fundus was examined and visual acuity was documented and compared to that of the fellow eye. Any reoperations were evaluated. RESULTS: In 98.7% of cases permanent reattachment of the retina was achieved. In 85.9% the primary intervention had been successful. However, the retina redetached in 19.4% of these during the first 3 months and in a further 4.5% later during the observation period, requiring reoperation. The average number of operations necessary to obtain permanent reattachment of the retina in the 77 eyes was 1.39. One eye was lost due to phthisis bulbi and had to be enucleated. Six years after the first intervention visual acuity of the eyes without reoperation was 0.57 (+/-0.25 SD) with initially detached macula [fellow eye 0.67 (+/-0.27)] and 0.7 (+/-0.27) with attached macula [fellow eye 0.7 (+/-0.25)]. Visual acuity of the eyes with reoperation was 0.36 (+/-0.3) [fellow eye 0.51 (+/-0.29)] with initially detached macula and 0.64 (+/-0.26) [fellow eye 0.63 (+/-0.35)] with attached macula. CONCLUSION: Six years after initial pneumatic retinopexy the retina was found to be attached in 98.7% of eyes. In 65.4% this result had been achieved by minimally invasive primary surgery alone. The need for reoperation was evident during the first 3 months in 89% of the cases. The final visual outcome was satisfactory overall.

Adult↗

Radiotherapy for age related macular degeneration causes transient lens transparency changes.

AIM: Evaluation of potential side effects of photon radiotherapy on the transparency of the lens. METHODS: The anterior segments of 14 phakic eyes from patients suffering from subfoveal neovascularisation as a result of age related macular degeneration (AMD) were documented by Scheimpflug photography (Topcon SL-45, Kodak Tmax 400) before the start of radiotherapy as well as 6 and 12 months afterwards. All negatives were evaluated by microdensitometry, and peak heights for distinct layers of the lens were used for statistical comparison. External beam radiotherapy (6 MeV photons) consisted of a total dose of 20 Gy, delivered as 10 fractions of 2 Gy. RESULTS: Six and 12 months following irradiation statistical comparison of the ratios in density change of lenses from irradiated versus non-irradiated fellow eyes revealed statistically significant (p</=0.05) loss of transparency of layers 5 and 7 of the nuclear region. In layer 1 (capsuloepithelial complex) the changes were close to significance. At the 12 month examination, however, all of these significant changes had disappeared. CONCLUSION: Six months following radiotherapy for AMD, both the anterior capsuloepithelial region and the nuclear layers showed precataractous changes. As most of these significant differences had disappeared after 12 months, it is obvious that these findings reflect acute radiation damage to the lens epithelial cells and an ionising effect on the proteins of the lens nucleus. Long term studies will have to be carried out to demonstrate whether or not this acute radiation damage, which is expressed as a transient increase in light scattering of some layers of the lens, actually does lead to permanent transparency changes, thus reflecting radiation cataractogenesis, and if so, after what time interval and to what extent cataract occurs.

Aged↗

Fixation monitoring during radiation therapy for subfoveal neovascularization.

PURPOSE: The aim of the study was to determine movement of the fovea during each irradiation session by monitoring movement of the cornea. Knowing the extent of foveal deviation permits minimization of the field size. METHODS: (1) Eye movement was monitored in 10 patients during irradiation. A TV camera with an attached fixation light was installed 3 cm away from the cornea of the treated eye. The fixation light was positioned at a 10 degrees angle to the TV camera on the opposite side of the gantry, resulting in a 90 degrees angle between the optical axis of the eye and the irradiation beam. (2) The relationship between movement of the anterior and posterior eye segments of 10 volunteers was examined using a scanning laser ophthalmoscope (SLO). Volunteers were asked to fix their gaze on positioning lights installed in the SLO. Gaze movements of the anterior and posterior eye segments were recorded simultaneously. RESULTS: (1) The patients' ability to retain fixation differed interindividually. The median corneal deviation during 10 irradiation sessions was 1 mm mediolaterally and 0.7 mm craniocaudally. (2) Deviation of the fovea could be determined by monitoring deviation of the cornea. Measured by SLO, the correlation between movements of the anterior and posterior eye segments was 1:0.9 horizontally and 1:1.5 vertically. CONCLUSION: (1) Irradiation field size can be reduced, depending on the patient's fixation stability. (2) If monitoring reveals a foveal deviation beyond the 95% isodose, irradiation can be interrupted.

Choroidal Neovascularization↗