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Biomedical subjects

O Ehrt

Publications and source records attributed to O Ehrt.

15 recordsLinked to original sources

[The combination of eye muscle surgery with other interventions on or in the eye].

Strabismus and motility disorders of the eye can be linked in many different ways to intraocular diseases and disorders of the lid and orbit. Different functional aspects have to be considered before performing combined eye muscle and intraocular or adnexal surgery. This allows to avoid unnecessary operations, to choose the right dosage of the operation, to limit the risk of diplopia, and finally to achieve a satisfying result for the patient.

Combined Modality Therapy↗

A concept for the surgical treatment of trochlear palsy.

The outstanding clinical symptom of acquired uni- and bilateral trochlear palsy is excyclotropia which increases in down-gaze. Any surgical treatment must aim at reducing this deviation. To achieve this, we have routinely used a modification of the Harada-Ito operation over the last 20 years. The anterior part of the tendon is pulled anteriorly and laterally by a loop of unresorbable suture. This not only increases incyclotorsion but also depression in adduction and reduces the V-pattern. In cases with more than 5 degrees vertical deviation, we performed an additional tuck of the posterior part of the tendon. Our results are compared with those of either superior oblique tuck or combined operations on the oblique muscles published by other authors. They have also used the Harms' tangent screen for quantification of the effect of the operations. In down-gaze, similar results have been obtained but less postoperative Brown's syndrome was found with our modified Harada-Ito procedure. Thus, our modification of the Harada-Ito procedure is an effective and safe approach to the surgical treatment of trochlear palsy with less postoperative limitation of elevation and less torsional overcorrection in up-gaze.

Head Injuries, Closed↗

[Scanning laser ophthalmoscope multifocal electroretinography and microperimetry in patients with Stargardt's disease].

PURPOSE: We used a scanning laser ophthalmoscope (SLO) evoked multifocal electroretinography (mf-ERG) to evaluate retinal function in patients with Stargardt's disease. SLO microperimetry could demonstrate the size of central retinal scotoma very well in these patients. The aim of the examination was to correlate the results of SLO mf-ERG and SLO microperimetry. METHODS: In four patients with Stargardt's disease SLO mf-ERG and SLO microperimetry were performed. The area of measurement in the SLO mfERG had a 24 degrees diameter (12 degrees visual angle) at the posterior pole of the eye. Stimulation was done using a helium-neon laser (632.8 nm). Simultaneous control of fixation was made using a infrared laser (730 nm). SLO microperimetry was performed with stimuli having the size of Goldmann III stimuli and the intensities 0 dB, 12 dB and 20 dB. In this study the reduction of SLO mfERG amplitudes was correlated to graded stimulus intensities in the SLO microperimetry. RESULTS: The area of reduced retinal function in the SLO mf-ERG measurement could be well correlated to the size of the scotoma in the SLO microperimetry, using the stimulus Goldmann III with the intensity 20 dB. CONCLUSION: SLO mfERG and SLO microperimetry are sensitive methods for quantifying functional deficits and are therefore useful for performing a detailed examination of the retina.

Adult↗

[Echographic differential diagnosis of optic nerve widening].

INTRODUCTION: Standardized echography is a well-established examination technique in ophthalmology. Among other things one of the more important uses is the evaluation of the optic nerve and its abnormalities. One aspect is the use of the stretch-test (originally called the "30 degrees-test") for the differential diagnosis of optic nerve widening. Such widening can be caused by solid thickening of the optic nerve and/or its sheaths or by solid infiltration of the subarachnoidal space. More frequent is a widening of the optic nerve as a consequence of sheath distension by increased subarachnoidal fluid. PATIENTS AND METHODS: We present various cases of widened optic nerve patterns and explain the technique and diagnostic value of standardized echography, especially of the stretch-test. RESULTS: In widened optic nerve patterns due to fluid around the optic nerve parenchyma, a decreased optic nerve thickness will be found when performing the stretch-test (positive test result), whereas in solid lesions of the optic nerve no change of optic nerve thickness will be seen (negative test result). CONCLUSION: The stretch-test provides a reliable tool for the differential diagnosis of widened optic nerves.

Adult↗

[Preoperative scanning laser ophthalmoscopy: findings in idiopathic macular foramen].

BACKGROUND: The aim of our study was a detailed morphological and functional assessment of macular foramen stages II-IV by scanning laser ophthalmoscopy (SLO) and fundus perimetry including a correlation with clinical findings. METHODS AND MATERIALS: Included in this prospective study were 78 patients where SLO imaging and fundus perimetry were performed with the SLO-105 (Rodenstock) prior to pars plana vitrectomy for macular foramen on one eye. Both the size and shape the of macular foramen were assessed. Deep (0 dB) and relative (12 dB) scotomata were tested using the Goldmann II stimulus in the 20 degrees field of the SLO. Imaging was performed with the infrared laser and confocal aperture C2. RESULTS: The size of macular foramen ranged from 140 microns to 800 microns (median: 420 microns) and 20 (26%) had irregular, polycyclic borders. In 21 patients (27%) a bright sector could be seen just outside the hole. Deep scotomata were notably smaller than the visible macular hole in 4 patients (6%) and 18 deep scotomata (25%) extended beyond the hole. There was a weak inverse correlation between the size of deep, relative scotomata and the diameter of the macular holes with the visual acuity (r = -0.46; r = -0.39 or r = -0.53), but no correlation with the duration of symptoms could be demonstrated. CONCLUSION: Polycyclic borders were seen as a new feature of some idiopathic macular foramen. This may be due to asymmetric traction or adhesions on the macular area. Also, deep scotomata either smaller or larger than the visible macular hole were found.

Aged↗

[Electronic versus paper-based patient records: a cost-benefit analysis].

BACKGROUND: The aim of this study is to compare the costs and benefits of electronic, paperless patient records with the conventional paper-based charts. METHODS: Costs and benefits of planned electronic patient records are calculated for a University eye hospital with 140 beds. Benefit is determined by direct costs saved by electronic records. RESULTS: In the example shown, the additional benefits of electronic patient records, as far as they can be quantified total 192,000 DM per year. The costs of the necessary investments are 234,000 DM per year when using a linear depreciation over 4 years. In total, there are additional annual costs for electronic patient records of 42,000 DM. Different scenarios were analyzed. By increasing the time of depreciation to 6 years, the cost deficit reduces to only approximately 9,000 DM. Increased wages reduce the deficit further while the deficit increases with a loss of functions of the electronic patient record. However, several benefits of electronic records regarding research, teaching, quality control and better data access cannot be easily quantified and would greatly increase the benefit to cost ratio. CONCLUSION: Only part of the advantages of electronic patient records can easily be quantified in terms of directly saved costs. The small cost deficit calculated in this example is overcompensated by several benefits, which can only be enumerated qualitatively due to problems in quantification.

Cost-Benefit Analysis↗

Scanning laser ophthalmoscope fundus cyclometry in near-natural viewing conditions.

BACKGROUND: For a better understanding of motor and sensory adaptations in cyclodeviations, subjective and objective ocular torsion have to be measured under the same conditions. The search coil technique and videooculography allow natural viewing but only assess relative cycloduction, the dynamics of torsion over a short period of time. Cycloposition, on the other hand, can be measured by analysing the position of the foveola relative to the optic disc with fundus photographs but only in nonphysiological viewing. The aim of the study was to develop a technique that allows natural viewing conditions during fundus cyclometry. METHODS: The scanning laser beam of the SLO was deflected by 90 degrees with a semitransparent mirror in front of the patient's eyes. The patient was able to look through the semitransparent mirror with both eyes into the room, e.g. at Harms' tangent screen. The infrared SLO images the central retina via the mirror through the undilated pupil. Digital image analysis quantifies the cycloposition of the eye. Controlled head movements while fixating the centre of Harms' tangent screen allow measurements in reproducible gaze positions. RESULTS: The semitransparent mirror reduces SLO image brightness, but image quality is sufficient for cyclometry after contrast enhancement. The laser light can be vaguely perceived by the patient but does not interfere with natural viewing. Reproducibility of the measurement is within +/- 1 degree SD. CONCLUSION: Our modification of SLO fundus cyclometry allows direct measurements of cycloposition in natural viewing conditions. This opens a new field for investigations of cyclodeviations and their sensory and motor adaptations.

Accommodation, Ocular↗

Macular changes after peeling of the internal limiting membrane in macular hole surgery.

PURPOSE: To report the incidence of macular changes following pars plana vitrectomy with peeling of the internal limiting membrane (ILM) for idiopathic macular hole. DESIGN: Prospective consecutive series. METHODS: In a prospective study 105 eyes of 105 patients underwent vitrectomy for idiopathic macular holes. Surgery consisted of a standard three-port vitrectomy, induction of a posterior hyaloid detachment, removal of epiretinal membranes including the ILM, fluid-air exchange and intraocular gas tamponade (15% hexafluoroethane (C2F6) gas mixture) followed by head-down positioning for at least five days. No adjuvants were used during surgery. In addition to the clinical examination, static microperimetry using a Rodenstock scanning laser ophthalmoscope (SLO-105) was performed pre- and 6 or 12 weeks postoperatively. The stimulus size was 0.2 degrees (Goldmann II), intensities employed were 0 and 12 dB. For all tests, 20-degree fields were used. RESULTS: Anatomic closure of macular holes was achieved in 92 (87.6%) of 105 patients by one operation. Eight patients underwent a successful second procedure. The closure rate after two operations was 95.2%. Best corrected visual acuity increased from a median of 0.2 (range 0.05 to 0.5) preoperatively to a median of 0.5 (range 0.05 to 1.0) postoperatively. Anatomical macular changes were found in 8 (7.6%) patients: There were two cases of macular edema following secondary cataract extraction and six cases of retinal pigment epithelium changes. Formation of postoperative epiretinal membranes or late reopenings were not noted. Small, mostly asymptomatic paracentral scotomata were seen in 59 (56.2%) of 105 patients. CONCLUSION: Anatomical changes of the macula following vitrectomy with removal of the ILM are infrequent. However, paracentral scotomata observed in our series might be caused by a trauma to the nerve fibers during ILM peeling. To achieve reliable results a standardized procedure for microperimetry should be developed.

Aged↗

Paracentral scotomata: a new finding after vitrectomy for idiopathic macular hole.

AIMS: To report the occurrence of paracentral scotomata after pars plana vitrectomy for idiopathic macular holes. METHODS: In 15 patients static microperimetry using a Rodenstock scanning laser ophthalmoscope (SLO-105) was performed preoperatively and 6 or 12 weeks postoperatively (stimulus size 0.2 degrees (Goldmann II), employed intensity 0 and 12 dB, 20 degrees fields in all tests). Surgery consisted of standard three port vitrectomy including removal of epiretinal membranes and the inner limiting membrane. RESULTS: Postoperative paracentral scotomata were detected in areas that were tested normally before surgery. They were mostly located temporally and/or inferiorly and often appeared like nerve fibre bundle defects. The greatest dimension varied from 1.2 degrees to 4.0 degrees (360-1200 microm), smallest dimension from 0.25 degrees to 2.0 degrees (75-600 microm). In three patients more than one scotoma was observed. CONCLUSION: Small, mostly asymptomatic, paracentral scotomata as a complication after vitrectomy for idiopathic macular hole have not been reported in the literature so far. Whether they are caused by trauma to the nerve fibres during surgery or other factors remains unknown.

Aged↗

[Functional results after surgical extraction or photocoagulation of choroid neovascularization (CNV) in age-related macular degeneration].

BACKGROUND: SLO microperimetric examination after the extraction of choroidal neovascular membranes (CNV) in age-related macular degeneration (AMD) shows absolute scotoma in the area of pigment epithelial loss. Laser treatment also causes complete functional loss. The functional results of these two methods should be compared before the surgical procedure is expanded. METHODS AND PATIENTS: Five eyes of five patients with large subfoveal well-defined CNV were treated by photocoagulation following the MPS criteria. Functional results were compared with similar phenotypes from a group of 78 patients operated upon. Before and after the treatment visual acuity was tested following the ETDRS criteria. The need for magnification for reading was tested using the ZEISS charts. Fundus-controlled microperimetry was performed using the scanning laser ophthalmoscope (Rodenstock) to detect deep and relative scotomata. RESULTS: The recurrence rate (OP 2/5; ALK 1/5) was normal regarding the small number of patients. Visual results are slightly better in patients operated on (mean: pre 0.08; 6 weeks 0.09; 3 month 0.13; last 0.13) than in laser-treated patients (mean: pre 0.06; 6 weeks 0.07; 3 months 0.08; last 0.12). Deep scotoma can be reduced with surgical extraction of the CNV (mean factor: 6 weeks 0.6; last control 0.8) while laser treatment of the margins enlarges the scotoma (mean factor: 6 weeks 2.3; last control 2.2). CONCLUSIONS: Because of the minimal functional advantages of the surgical procedure we do not think it is the method of first choice. For both methods the treatment of well-defined CNV increases the possibility of low-vision rehabilitation.

Age Factors↗

[Microperimetry and reading saccades in retinopathia solaris. Follow-up with the scanning laser ophthalmoscope].

UNLABELLED: Patients with solar retinopathy often complain of minute central scotomas and are handicapped when reading. The purpose of this study was to verify scotomas that are too small to be detected by standard perimeters and to analyze patients' reading patterns. METHODS: Nineteen patients (12 female, 7 male, aged 5-46 years) with acute solar retinopathy after watching a solar eclipse on 12 October 1996 underwent scanning laser ophthalmoscope (SLO) microperimetry within 10 days after exposure using stimulus size Goldmann I (0.11 degree) with the 20 degrees field. Size and depth of scotomas were measured. Eye movements during reading were recorded on videotape. Follow-up was at 1 and 6 months. RESULTS: Thirty-one eyes (7 patients unilateral, 12 bilateral) showed scotomas. Four eyes showed anatomic changes in the retinal pigment epithelium but no functional loss. VA was 0.16 to 0.5 in 5 eyes, 26 had VA of 0.8-1.2. Scotomas could be detected in all eyes with subjective impairment. Scotoma size varied from 0.3 to 1.7 degrees (1 patient 6 degrees). Forty-four percent were deep scotomas (0 dB). All defects improved at 1 and at 6 months; 25% were no longer detectable. Reading speed was reduced in 75% of eyes (42% at 6 months): 200-560 signs/min, median: 510, normal > or = 660 (at 6 months: 350-920 signs/min, median 670). This was especially due to increased number of regressions (in 81% of eyes, 21% at 6 months). The frequency and width of saccades were no different from normal subjects. CONCLUSION: Minute scotomas (diameter = 0.3 degree) can be detected with the SLO. All patients showed objective improvement of their field defect up to 6 months, even when this was not noted by the patient or thought to be due to habituation. Small scotomas can dramatically reduce reading performance.

Adolescent↗

[Surgical removal of subfoveal choroid neovascularization in senile macular degeneration].

UNLABELLED: The follow-up of central scotomas and fixation--next to visual acuity--are important parameters for the evaluation of new therapies in AMD. PATIENTS AND METHODS: Twenty-three patients (age 67 to 91 years) with subfoveal CNV had SLO fundus-controlled perimetry before and 6-8 weeks after surgical removal of the CNV. The size and location of deep (0 dB) and relative (12 dB) scotomas were measured. Stability and location of fixation were analyzed. RESULTS: Fifty-six percent of patients gained (10% lost) more than 2 lines of VA; 52% of deep scotomas decreased in size (26% increased). No relative scotoma increased, but 63% decreased, some remarkably. Most scotomas had steeper borders postoperatively. Five of 7 patients were able to fixate again. Fixation moved slightly more peripheral in 4 patients and was otherwise unchanged. None of 7 patients whose fixation was close to their fovea preoperatively lost that fixation. CONCLUSION: Subfoveal surgery may stabilize the course of subfoveal CNV in AMD at 6 weeks follow-up. In some patients the major benefit can be a reduction of relative scotoma due to reattachment of the retina. As the location of fixation changes little with surgery and is typically located within the area of relative scotoma, visual function can improve.

Aged↗

[North Carolina macular dystrophy. Hereditary macular disease with good functional prognosis].

BACKGROUND: North Carolina macular dystrophy (NCMD) is a rare autosomal dominant maculopathy with highly variable expressivity. Genetic analysis of an American family consisting of 247 members out of which 96 were affected with NCMD allowed chromosomal assignment of the NCMD locus to 6q14-q16.2. Few families with NCMD are known in Europe, one of these is living in Germany. By routine investigation, a second family affected with NCMD was detected in Germany. As some authors still doubt the good prognosis of this disease, our results should be added to the experience of others. PATIENTS AND METHODS: In a total of 18 family members from three generations between the age of 2 and 65 years, clinical investigations and genetic analysis was carried out. Some individuals had additional examinations such as colour contrast sensitivity, EOG, ERG, and microperimetry. RESULTS: Ten of 18 family members turned out to be affected. All grades of NCMD were present with great variability. Visual acuity ranged from 0.32 to 1.0 and did not correlate to the grade of the disease or to the age of the person. In those patients who underwent microperimetry, central fixation was confirmed. Genetic linkage analysis further narrowed the region harbouring the NCMD locus and supported the assumption that the central areolar pigment epithelial dystrophy (CAPED) is an allelic disorder. CONCLUSION: Similar visual acuity in three generations of NCMD patients supports the observation that NCMD is not a progressive disorder. If geographic atrophy is found in a patient with good visual acuity, NCMD should be considered and genetic analysis should be carried out.

Adolescent↗

[Computer program for improved diagnostic coding in ophthalmology based on the expanded ICD 10].

BACKGROUND: The coding of ophthalmological diagnoses is a long-standing problem that has recently been highlighted by the planned introduction of ICD 10. METHODS: Using an alphanumerical classification system for the first time, ICD 10 offers the space needed for necessary expansion without leading once again to dislocations in the numbering system. The FoxPro 2.5 database system was used to create a program based on an expanded ICD 10 that can be applied from DOS and Windows. RESULTS: ICD 10 was expanded by the addition of a numerical fifth digit, thus increasing the number of classifiable ophthalmological disorders by a factor of 4.2 from 390 to 1635. The new program greatly facilitates the handling of this substantial amount of data. CONCLUSIONS: The enhanced diagnosis coding achieved with the expanded ICD 10 permits nosologically exact statistics to be kept for use as a basis for further scientific work.

Data Display↗