[Quality demands on the assessment of colour vision]. / Qualitätsanforderungen an die Untersuchung des Farbsinns.

Assessing colour vision comprises a wide spectrum of methods, many of which are practical and highly informative. Given this methodological variety this review aims to help select the most appropriate test and how to correctly execute it, thus achieving the highest quality.Some aspects of the physiology of colour vision are covered as far as is necessary for a basic understanding of colour testing methodology and possible pitfalls. For congenital colour anomalies most pertinent are questions of occupational aptitude. For acquired colour deficiencies assessing colour vision supplements diagnostics of the retina and the visual pathway, allowing both early diagnosis and/or monitoring. For both these fields colour tests provide different kinds of evidence and need to be adequately selected. Methodical artefacts due to both equipment design properties and testing procedures are highlighted so they can be avoided. A form is presented for recording colour examination results commensurate with quality objectives. Finally, a tabular overview of 19 common colour vision tests is provided.

[Photopic contrast sensitivity. Local contrast perception]. / Photopisches Kontrastsehen. Ortliche Kontrastempfindlichkeit.

Contrast perception is an important visual function. Contrast sensitivity (CS) is affected by to optical reasons (aberrations, scatter, diffraction) or neural dysfunction (e.g., glaucoma, optic nerve diseases). In clinical practice the measurement of CS is relevant for disease monitoring, expert opinions, roadworthiness assessment, and recruitment screening. Furthermore, CS testing is often required in studies assessing optical quality, e.g., cataract or refractive surgery. Adding an appropriate glare source allows measurement of the glare-induced loss of CS (disability glare). Compared to high-contrast acuity, CS is more variable and strongly depends on the type of test, illumination, test strategy, and contrast definition; ceiling effects are quite common among many tests. Maximal standardization is important, especially for follow-up exams. In summary, CS testing cannot be regarded as a routine test. The present report by the DOG commission for quality management of psychophysical assessment covers the physiological background, testing principles, and strategies and presents a tabular overview of common tests.

[Determination of visual function in legal assessment]. / Objektivierung der Sehfunktionen bei Begutachtungen.

For the determination of visual function an objective assessment is essential. Basic ophthalmologic examinations such as measurement of visual acuity and perimetry are dependent on patient statements. If the patient is not being able to provide adequate answers, as is the case for small children or mentally retarded patients, or also if the accuracy of the patient's statements is doubtful or simulation or aggravation is suspected, the denoted function in the evaluation of visual acuity has to be checked on consistency using different examination methods, and the results of objective functional tests, such as electrophysiology and morphological features, have to be taken into account.

[Severe course and contingent risk factors in optic neuropathy and myelopathy after tuberculostatics]. / Schwerwiegender Verlauf und belastende Faktoren bei Optikusneuropathie und Myelopathie durch Tuberkulostatika.

A male patient with tuberculous lymphadenopathy was treated with a four-fold therapy of ethambutol, isoniacide, rifampicin and pyracinamide. After 10 weeks the patient suffered from photophobia. Although ethambutol was discontinued vision decreased and visual field defects occurred as well as signs of myelopathy. Isoniacide was then discontinued and in the subsequent phase the vision was slowly restored over a period of 36 months. The combined toxicity of ethambutol and isoniacide seems to have been the main cause of the severe and protracted optic neuropathy.

Multifocal ERG recording with simultaneous fundus monitoring using a confocal scanning laser ophthalmoscope.

PURPOSE: To assess the general feasibility of recording multifocal electroretinograms (mfERGs) with simultaneous fundus monitoring in a clinical setting. METHODS: An mfERG system (RETIscan) and a confocal scanning laser ophthalmoscope (Heidelberg Retina Angiograph) were connected to record mfERGs elicited by a pseudorandom binary m-sequence stimulus generated by a 514 nm laser source. Recordings were compared to a conventional mfERG system using monitor stimulation. A total of five subjects (two normal subjects and three patients) were examined. RESULTS: In normal volunteers records obtained by the fundus-monitored mfERG showed highest response densities in the central fundus area and a decrease of response amplitudes towards the periphery paralleling cone receptor density. However, compared to the monitor stimulation, the drop-off of amplitudes as a function of eccentricity was not as clearly defined. The responses obtained from patients with retinal diseases were diminished in the areas of retinal dysfunction. CONCLUSIONS: These preliminary findings indicate that the technique of laser stimulation in principle allows for topographic retinal recording. This method might be useful, for example if the retinal position of the stimulus array is not centred onto the fovea but deviates due to fixation problems. However, further improvement of the technique appears necessary before considering routine clinical application.

[Diagnosis of retinal diseases. Comparison between multifocal ERG and fundus perimetry - a case study]. / Diagnostik bei Netzhauterkrankungen Vergleich von multifokalem ERG und funduskontrollierter Perimetrie - Fallstudie.

BACKGROUND: There are new methods available for function testing of the macula, i.e. multifocal Electroretinography (mfERG) as well as fundus perimetry with the scanning laser ophthalmoscope (SLO). The value and clinical impact of these methods have still to be evaluated. We wanted to compare the results from patients having undergone both examinations. PATIENTS AND METHODS: A total of 33 eyes from 25 patients (visual acuity 0.03-0.8) aged 14-79 years were examined using fundus perimetry with the SLO. In addition, multifocal ERG was performed in all eyes, where 61 local ERGs inside the 30 degrees visual field were recorded. We compared the depth of the scotoma with the reduction of the amplitudes during mfERG taking the fixation status into consideration. RESULTS: Examination time was comparable for both examination techniques. There was good concordance for eyes with retinitis pigmentosa with only central response. In contrast, patients with juvenile macular dystrophy demonstrated different results with comparable size of the defect while sometimes an enlarged pathology during mfERG was observed. Correlation between pathology findings observed in mfERG and fundus changes was difficult due to the change of the point of fixation caused by central scotoma. In age-related macular degeneration correlation of the findings was less obvious. DISCUSSION: The different setting with supra-threshold stimuli during ERG in contrast to near-threshold stimulus presentation during perimetry, might be the reason for differences even in the beginning of retinal diseases. In addition, reduced stability of fixation leads to artifacts during mfERG while it may be compensated for in fundus perimetry. Both methods are of additional value and demonstrate different results depending on the disease.

[Multifocal ERG with confocal scanning laser ophthalmoscope. Comparison with monitor simulation]. / Multifokales ERG mittels konfokalem Scanning Laser Ophthalmoskop. Vergleich mit Monitorsimulation.

BACKGROUND: Multifocal electroretinograms (mfERG) were recorded using a confocal scanning laser ophthalmoscope (cSLO) and compared to the results from conventional monitor stimulation. METHODS: Single and repeated measurements were recorded from 23 normal subjects using the cSLO (Heidelberg Retina Angiograph, Heidelberg Engineering, Heidelberg) as well as a conventional monitor as stimulation devices. Laser power output was modified by various optical filters. The reliability of the method and agreement with the conventional monitor stimulation were determined. RESULTS: CSLO recordings showed a high degree of variability. Reduction of laser power output improved the retinal response topography and characteristically modified response variations with each filter. Differences in amplitude size between cSLO and monitor recordings decreased with increasing amplitude levels. The results of repeated measurements showed considerable variation. CONCLUSION: It is possible to use a cSLO as a stimulator for mfERG recordings. However, a relatively high degree of variability represents a significant limitation of this method. Appropriate reduction of laser power decreases variations and serves to obtain photopic response topographies.

Immune-mediated retinopathy in a patient with stiff-man syndrome.

BACKGROUND: Stiff-man syndrome is a rare neurological disorder characterised by rigidity and violent spasms of the body musculature. In the majority of patients, presence of antibodies against glutamic acid decarboxylase (GAD), the enzyme synthesizing gamma-aminobutyric acid (GABA), suggests an autoimmune attack against GABA-ergic inhibitory neurons. We report a 32-year-old patient with stiff-man syndrome and anti-GAD antibodies who developed subacute progressive loss of vision in the right eye, and in the left eye 18 months thereafter. METHODS: Ophthalmological work-up included electro-retinogram (ERG), visual evoked potentials (VEP) and fluorescein angiography. Antiretinal antibodies were investigated using an indirect immunofluorescence technique on frozen sections of macaque retina with patients serum and FITC-conjugated goat antihuman immunoglobulin. Staining with monoclonal anti-GAD65 antibodies and with serum from three healthy normals served as controls. RESULTS: Visual acuity of both eyes decreased to 0.16 within a span of 6 weeks. Perimetry revealed a central scotoma in the visual field of both eyes. VEP and flash ERG were progressively disturbed on the right eye. On the left eye, initially only pattern ERG and photopic responses were abnormal. Follow-up recordings revealed widespread pathology of photopic single and flicker responses. Immunofluorescence revealed strong reactivity of the inner plexiform layer and to a lesser extent staining of the outer plexiform layer at dilutions of 1:1000 with patients serum. The same retinal staining pattern was obtained with monoclonal anti-GAD65 antibodies. CONCLUSIONS: These findings suggest autoimmune retinopathy, mediated by anti-GAD65 autoantibodies as the underlying cause of visual loss.

[Standardized evaluation of red, green and blue perception. Comparison between color arrangement and computer-assisted test procedures]. / Standardisierte Prüfung des Rot-, Grün- und Blausinns. Vergleich zwischen Farbfleck- und computergestütztem Testverfahren.

BACKGROUND: Computerized colortests offer the possibility of determining quantitative color contrast thresholds under standardized conditions. Arrangement tests allow semi-quantitative evaluation of the red, green and blue color sense. To validate the results of a new computerized test, its results are compared to those of arrangement tests. PATIENTS AND METHODS: Thirty-five patients with retinitis pigmentosa (RP, mean age 38.51, +/- 15.14) as well as 30 normal observers (mean age 36.52, +/- 14.33) were evaluated. The computerized color test COLDEF was used, which is a calibrated screen that presents color optotypes on a colored background. All colors are chosen from three-color confusion axes of the CIE-Lu'v' color chart (protan, deutan and tritan axis). By a staircase procedure, the colors of the optotype and background were varied until the observers minimal color contrast threshold is detected. To compare the results of COLDEF with a routine diagnostic tool, the Farnsworth panel D-15 and Lanthony désaturé test were chosen. The results of the arrangement tests were scored by a categorization scheme. RESULTS: Normal observers showed no elevated thresholds either in COLDEF nor in the panel tests. In the RP group increased thresholds along the blue confusion axis could be detected in most cases. Furthermore, COLDEF showed increased thresholds along the red and green axes in some patients. With the computerized test it is always possible to identify the color axis concerned. The new test allows a fast and quantitative assessment of acquired color vision deficiencies.

[Complicated cataracts in various forms of retinitis pigmentosa. Type and incidence]. / Cataracta complicata bei verschiedenen Formen der Retinitis pigmentosa. Art und Häufigkeit.

PURPOSE: To study the incidence and types of cataract in retinitis pigmentosa (RP) and their variations among different forms of RP. PATIENTS AND METHODS: This analysis was based on data from 473 patients with RP (autosomal dominant, n = 87; autosomal recessive, n = 79; x chromosomal recessive, n = 23; simplex RP, n = 215; Usher's syndrome n = 80; M. Refsum and others, n = 9) that were retrieved from the literature and patient charts in our clinic. RESULTS: Posterior subcapsular cataract (PSC) developed with the following frequencies for the different genetic types of RP: autosomal dominant, 45.3%; autosomal recessive, 44.0%; x chromosomal recessive, 40.7%; simplex RP, 46.1%; Usher's syndrome, 52.9%. PSC was the only type of lens opacity in patients with Usher's syndrome and autosomal recessive RP.PSC development correlated with early onset of RP symptoms. Nuclear cataracts showed a statistically significant higher frequency in patients with simplex RP (14.8%) than in other genetic types (0-5.9%) (P < 0.01). In addition, nuclear cataracts developed in simplex RP at a significantly later age (69.6 +/- 12.4 years) than PSC (44.4 +/- 12.3 years) (P < 0.001). Patients with cataracts showed significantly worse visual fields than patients with clear lenses (P = 0.00067). CONCLUSIONS: The typical RP cataract (PSC) was found in similar frequencies among all genetic types of RP.PSC was the only type of lens opacity in patients with Usher's syndrome and autosomal recessive RP. Nuclear cataracts developed on average 20 years later than PSC and had their highest incidence in patients with simplex RP. Patients with cataracts showed significantly worse visual field results, indicating a more pronounced retinal pathology.

[Development of a standardized evaluation system for cataracta complicata in retinitis pigmentosa]. / Entwicklung eines standardisierten Bewertungsschemas der Cataracta complicata bei Retinitis pigmentosa.

INTRODUCTION: Retinitis pigmentosa (RP) is associated with the formation of a posterior subcapsular cataract (PSC). As only a small part of the crystalline lens is usually affected, it is sometimes difficult to determine to what extent the visual loss is caused by the PSC alone. PATIENTS AND METHODS: The methodology was developed in analogy to a scoring system for posterior capsule opacification by Tetz et al. Following dilation of the pupil, standardized photographs of the anterior segments were obtained utilizing a Zeiss photoslitlamp model 40 SL/P. The PSC was scored by evaluating retroillumination photographs. The individual PSC index was calculated by multiplying the density of the opacification (graded from 0 to 4) by the area involved in the central 4 mm zone of the pupil (calculated between 0 and 1). For testing the reliability of the evaluation system in part 1 of this study, 11 RP patients with different grades of PSC were examined by three independent observers. In part 2 of this study 37 eyes of 24 RP patients, aged 47.2 +/- 11.8 years, were evaluated and the PSC index was correlated with different parameters (visual acuity, age, visual fields, eletroretinography). RESULTS PART 1: The cataract-density grades were between 1 and 4 in the 11 patients. In relation to the central 4-mm pupillary zone between 13 and 100% of the area were opacified. Cataract indices (density x area) were between 0.13 and 4.0 (Mean values: Examiner 1:1.41 +/- 1.49; Examiner 2:1.28 +/- 1.46; Examiner 3:1.22 +/- 1.44; differences not significant: P = 0.77). PART 2: After an average duration of RP of 23 years, the average cataract index of the 24 patients was 1.72 +/- 1.35. There was no correlation between cataract index and ERG or visual fields (r < 0.2; P > 0.4); however, there was a good correlation to visual acuity (r = -0.72; P = 0.0001). Patients with early onset of RP (before 20th year of life) presented on average with an higher cataract index (2.06 +/- 1.67) compared to patients with late manifestation (0.61 +/- 0.44), but equivalent duration of RP. CONCLUSIONS: The evaluation system offers a reliable and reproducible method for measuring PSC density and extension in RP patients. The method can serve as a useful tool for documenting PSC development and help to define the indications for cataract surgery in RP.

[Carcinoma-associated retinopathy in breast carcinoma and carcinoid tumor]. / Karzinomassoziierte Retinopathie (CAR) bei Mammakarzinom und Karzinoid.

BACKGROUND: Carcinoma-associated retinopathy (CAR) is a rare paraneoplastic syndrome characterized by diffuse retinal photoreceptor degeneration in the presence of an epithelial tumor. We report on three patients, who developed paraneoplastic retinopathy in the presence of breast carcinoma and a cervical carcinoid tumor. MATERIALS AND METHODS: In addition to biomicroscopic, psychophysical, electrophysiological and angiographic examinations, serum samples were obtained for immunohistochemical staining of human retina. RESULTS: Ring-shaped visual field defects with statokinetic dissociation and abnormal rod and cone responses were found. Immunohistochemical findings included reactions at the level of the inner segments of the photoreceptors, the outer nuclear layer and the outer plexiform layer in absence of anti-recoverin antibodies. CONCLUSIONS: CAR should be considered in the differential diagnosis of visual loss in presence of tumors other than small-cell carcinoma of the lung. The presence of antiretinal antibodies is compatible with a tumor-induced immune response to epitopes shared by both the tumor and retinal tissue. Apparently, various retinal proteins may function as autoantigens.

[Paraneoplastic retinopathy in 2 patients with breast carcinoma]. / Paraneoplastische Retinopathie bei zwei Patientinnen mit Mammakarzinom.

Paraneoplastic retinopathies are rare paraneoplastic phenomena resulting in retinal degeneration. They occur in association with different tumor types, yet most frequently encountered in small cell carcinoma of the lung. Clinical symptoms may be present before the diagnosis of the underlying malignancy. They are characterized clinically by progressive visual loss with ring scotomas, photopsia and night-blindness. An autoimmune disorder is suggested. In the sera of patients antiretinal antibodies may be detected that are sometimes reactive with the 23 kD retinal antigen recoverin, a photoreceptorprotein. We report on two patients with breast cancer who developed paraneoplastic retinopathy during the course of disease. Immunologic tests showed antiretinal antibodies that were not reactive with the 23 kD retinal antigen recoverin.

[Increased cataract rate and characteristics of Nd:YAG laser capsulotomy in retinitis pigmentosa]. / Erhöhte Nachstarrate und Besonderheiten der ND:YAG-Laserkapsulotomie bei Retinitis pigmentosa.

BACKGROUND: Retinitis pigmentosa (RP) is associated with the development of a posterior subcapsular cataract (PSC). The development of posterior capsule opacification (PCO) after cataract surgery and a decrease of central visual acuity is sometimes misinterpreted by the patients as natural course of RP. Therefore, therapeutic intervention is often delayed. PATIENTS AND METHODS: In a retrospective study (part 1) the incidence of PCO was evaluated in a group of 26 RP patients who underwent cataract surgery and IOL implantation. In a prospective analyse (part 2) PCO was quantified in 13 RP patients using the standardized photographic technique and image analysis system introduced by Tetz et al. Matched pairs were formed with a control group of 13 patients without retinal disease who matched the RP group in terms of age distribution and postoperative follow-up time. In part 3 the parameters of Nd:YAG laser capsulotomy in 12 RP patients and 14 controls were evaluated. RESULTS: Part 1: The cumulative PCO rate in RP at the end of the first postoperative year was 14.6%, 26.8% in the second, 53.7% in the third and 70.7% after the third year. Nd:YAG laser capsulotomy was performed in 70% of eyes (after 18.4 +/- 14.7 months). In eyes with significant PCO development 70% had PSC preoperatively, while in eyes without PCO formation only 41.7% showed PSC. Part 2: The matched pairs analysis showed a significantly higher PCO value for RP patients (2.11 +/- 1.42) than for the control group (0.89 +/- 0.72) (P = 0.038). Part 3: Average Nd:YAG laser energy levels were 12.8 +/- 11.2 MJ (RP) and 7.6 +/- 6.7 MJ (control). Some 25% of RP patients required further laser treatment of regrown secondary cataract. CONCLUSIONS: Patients with RP showed a significantly higher incidence and density of PCO. Whether RP-specific pathomechanisms are responsible for this needs further investigation.

[Skin electrodes for electroretinography in unsedated children]. / Hautelektroden-ERG bei unsedierten Kindern.

Contact lens electrode ERG is not well tolerated by children. So far, skin electrode ERG has suffered from a weakly defined geometrical relationship to the sources of ERG potentials. Because of the cuplike electric ocular field distribution, skin electrodes were placed: (1) in the middle of the lower eyelid (in order to be positioned in close proximity to the anterior apex of the cornea, which belongs to the electropositive inner surface of the cup); (2) 20 mm laterally to the temporal canthus (in proximity to the cup's electronegative outer surface). (3) Grounding was achieved by attaching a third skin electrode in the forehead midline. Instead of complete dark adaptation, adaptive illumination of 0.1 cd.m-2 was used to avoid frightening the children. After 10 min of adaptation, the examination started. Feeling safe on mother's lap, the little patient looked into a frosted glass screen (about 75 degrees of visual angle, depicting Mickey Mouse) on which a series of strobe flashes was delivered along the lines of the ISCEV ERG Standard: (1) blue flashes: filter no. 625 (Röhm and Haas); repetition rate 0.1 Hz; stimulus strength of white flashes 1.5 cd.m-2 s; (2) red flashes: filter no. S502 (Röhm and Haas); repetition rate 1 Hz; stimulus strength of white flashes 21.75 cd.m-2.s; (3) weak white flashes: stimulus strength 1.5 cd.m-2.s; repetition rate 0.3 Hz; (4) strong white flashes: stimulus strength 11.25 cd.m-2.s; repetition rate 0.3 Hz; (5) white flicker flashes: stimulus strength 1.5 cd.m-2.s; frequency 10, 30, 60 Hz. Recording of single stimulus responses turned out to be feasible; however, to achieve the best results, between 8 and 32 ERG responses were averaged. To illustrate the benefits of skin electrode ERGs in practice, the results of some cases are presented and discussed with respect to clinical findings.