Following prevalence of myopia in a large Swiss military cohort over the last decade: where is the European "myopia boom"?

PURPOSE: Myopia prevalence is increasing globally, with the highest rates found in Asia. Data from European countries is scarce. We aimed to investigate whether the prevalence of myopia is rising in our meridians. METHODS: Data from male military conscripts for the recruitment period of 2008-2017 were retrospectively analyzed. Year of recruitment, conscripts' birth year, visual acuity, refractive status (spherical equivalent), and spectacle wear (yes/no) were available. RESULTS: The dataset contained data of a total of 355,657 male conscripts, who had been recruited in the years 2008 to 2017. The mean number of conscripts per year was 35,566 (MD = 35,440, SD = 1249), reaching a minimum number of 33,998 conscripts in 2017 and a maximum of 37,594 in 2011. Mean age at recruitment was 19.7 years (MD = 19.0 years, SD = 1.1 years). Overall, the number of conscripts wearing spectacles remained stable over the observation time; on average 29.6% (n = 10,540; MD = 10,472; SD = 492) of conscripts wore glasses at recruitment. Of 21.8% (n = 77,698) of conscripts, data on the refractive status was available: The mean spherical equivalent for both right and left eyes was -2.3D (MD = -2 D, SD = 2.4 D). No decrease in mean spherical equivalent per recruitment year was noted over the observation period. Estimated myopia prevalence reached an average of 27.5% (SD = 0.8%) and did not increase during the observation period. CONCLUSION: In summary, no change in spherical equivalent refractive errors of male Swiss army conscripts was found for the years 2008-2017. Equally, the percentage of spectacle wearers (MN = 29.6%) and estimated myopia prevalence (MN = 27.5%) did not significantly increase during the observation time. TRIAL REGISTRATION:  BASEC 2019-00060 (18/01/2019).

Analysis of Suspected Achromatopsia by Multimodal Diagnostic Testing.

BACKGROUND: Achromatopsia (ACHM) as a hereditary cone disease might manifest in a stationary and progressive manner. The proper clinical and genetic diagnosis may allow an individual prognosis, accurate genetic counselling, and the optimal choice of low vision aids. The primary aim of the study was to determine the spectrum of clinical and genetic diagnostics required to characterize the ACHM. METHODS: A retrospective analysis was performed in 8 patients from non-related families (5 ♀,3 ♂); age at diagnosis: 3 - 56 y, mean 18.13 (SD ± 18.22). Clinical phenotyping, supported by colour vision test, fundus photography-, autofluorescence- (FAF), infra-red- (IR), OCT imaging and electroretinography provided information on the current status and the course of the disease over the years. In addition, genetic examinations were performed with ACHM relevant testing (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H and the transcription factor ATF6). RESULTS: All patients suffered photophobia and reduced visual acuity (mean: 0.16 [SD ± 0.08]). Nystagmus was identified in 7 from 8 subjects and in one patient a head-turn right helped to reduce the nystagmus amplitude. Colour vision testing confirmed complete achromatopsia in 7 out of 8 patients. Electrophysiology found severely reduced photopic- but also scotopic responses. Thinning and interruption of the inner segment ellipsoid (ISe) line within the macula but also FAF- and IR abnormalities in the fovea and/or parafovea were characteristic in all ACHM patients. Identification of pathogenic mutations in 7 patients helped to confirm the diagnosis of ACHM (3 adults, 4 children; 3 ♀ and 4 ♂). Achromatopsia was linked to CNGA3 (2 ♀, 1 ♂) and CNGB3 variants (2 ♀, 3 ♂). The youngest patient (♀, 10 y) had 3 different CNGB3 variants on different alleles. In a patient (♂, 29 y) carrying 2 pathogenic digenic-triallelic CNGA3- and CNGB3-mutations, a severe progression of ISe discontinuity to coloboma-like macular atrophy was observed during the 12-year follow-up. The oldest female (67 y) showed a compound homozygous CNGA3- and heterozygous CNGB3-, as well as a heterozygous GUCY2D variants. The destruction of her ISe line was significantly enlarged and represented a progressive cone-rod phenotype in comparison to other ACHM patients. In a patient (♂, 45 y) carrying a pathogenic CNGB3 and USH2 mutation, a severe macular oedema and a rod-cone phenotype was observed. In addition, two variants in C2ORF71 considered as VOS were found. One patient showed the rare ATF6 mutation, where a severe coloboma-like macular atrophy was observed on the left eye as early as at the age of three years. CONCLUSION: Combining multimodal ophthalmological diagnostics and molecular genetics when evaluating patients with ACHM helps in characterizing the disease and associated modifiers, and is therefore strongly recommended for such patients.

Myopia Management in Daily Routine - A Survey of European Pediatric Ophthalmologists.

PURPOSE: Assessment of diagnostic and therapeutic strategies currently used in routine practice for myopia management in Europe. METHODS: Online survey study including 11 main questions. The questionnaire was sent to members of the European Paediatric Ophthalmology Society (EPOS). The following items and questions were surveyed: I. Profession and workplace of the survey participants. II. Preventive measures and recommendations for myopia management, a) regarding reading distance and near work, b) optical tools, i.e., application of Defocus Incorporated Multiple Segments (DIMS) glasses, near additions, or contact lenses, and c) the application of atropine eye drops. III. Application of additional diagnostic tools. RESULTS: Forty-eight individuals completed the survey. Of the respondents, 88% (n = 42) affirmed that they generally gave advice on strategies for myopia prevention and management strategies. Almost all study participants (n = 41; 85%) recommend outdoor time as a preventive measure. The recommendation on near distance is given less frequently, with 28 (58%) participants confirming that they do recommend a "safe" reading distance, and 15 (31%) negating this. Eight (17%) survey participants recommend using near addition glasses, while 36 (75%) do not. Similarly, 35 (73%) respondents do not apply DIMS glasses and 8 (17%) apply them. Fourteen (29%) participants recommend myopia-reducing contact lenses while 30 (63%) do not, and 29 (60%) confirmed that they applied atropine eye drops to slow myopia progression while 14 (29%) do not prescribe these eye drops. The majority of respondents (n = 25; 86%) who prescribe atropine eye drops use atropine 0.01% eye drops. CONCLUSIONS: Prevention and therapeutic management of childhood myopia is an essential part in the daily routine of pediatric ophthalmologists. Substantial agreement was found for the protective role of outdoor time (85%). The only common therapeutic approach is the administration of atropine eye drops (60%).

Pediatric reference values of anterior visual pathway structures measured with axis-correction on high-resolution 3D T2 fast spin echo sequences.

BACKGROUND: The size of the anterior visual pathway (AVP) structures is affected by patient age and pathology. Normative data is useful when determining whether pathology is present. AVP structures do not respect the standard planes of magnetic resonance (MR) imaging. The aim of this study was to produce normative age-related and axis-corrected data of the AVP structures using multiplanar reformation (MPR) of high-resolution 3D T2-weighted fast spin echo (3D T2w FSE) images. METHODS: For each patient 32 measurements of AVP structures were obtained in 145 children (2 months - 18 years) with normal brain MR studies on high-resolution 3D T2w FSE images adjusted to the axis of each AVP structure. Descriptive statistics were calculated for different age classes and growth models were fitted to the data and assessed for their performance to create a formal statistical model that allows inference beyond the sample. RESULTS: Descriptive statistics were compiled in a reference table and prediction plots in relation to age, height, and body surface area (BSA) were obtained from the best overall performing statistical model, also taking field strength (1.5 vs. 3 T) into account. Intraclass correlation coefficient values were calculated for all variables ranging from 0.474 to 0.967, the most reliable being the transverse diameter of the globe, the maximum diameter of the retrobulbar nerve sheath, the intracranial segment of the optic nerve and the transverse diameter of the chiasm. The maximum retrobulbar diameter of the optic nerve sheath and the lateral superoinferior diameter of the chiasm showed no statistically significant change with age. CONCLUSION: Detailed charts of reference values for AVP structures as well as prediction plots in relation to age, height and BSA were established using axis-corrected measurements from the MPR of high-resolution 3D T2w FSE images. Furthermore, an Excel spreadsheet that allows users to calculate normative values for the 9 AVP structures of key interest is provided as supplementary material.

Central Retinal Artery Occlusion: Current Practice, Awareness and Prehospital Delays in Switzerland.

Background and Purpose: Central retinal artery occlusion (CRAO) often leads to permanent monocular blindness. Hence, early recognition and rapid re-perfusion is of paramount importance. This study aims to describe prehospital pathways in CRAO compared to stroke and study the knowledge about CRAO. Methods: (1) Description of baseline characteristics, prehospital pathways/delays, and acute treatment (thrombolysis/thrombectomy vs. standard of care) of patients with CRAO and ischemic stroke registered in the Swiss Stroke Registry. (2) Online survey about CRAO knowledge amongst population, general practitioners (GPs) and ophthalmologists in Eastern Switzerland. Results: Three hundred and ninety seven CRAO and 32,816 ischemic stroke cases were registered from 2014 until 2019 in 20 Stroke Centers/Units in Switzerland. In CRAO, 25.6% arrived at the hospital within 4 h of symptom onset and had a lower rate of emergency referrals. Hence, the symptom-to-door time was significantly longer in CRAO compared to stroke (852 min. vs. 300 min). The thrombolysis/thrombectomy rate was 13.2% in CRAO and 30.9% in stroke. 28.6% of the surveyed population recognized CRAO-symptoms, 55.4% of which would present directly to the emergency department in contrast to 90.0% with stroke symptoms. Almost 100% of the ophthalmologist and general practitioners recognized CRAO as a medical emergency and 1/3 of them considered IV thrombolysis a potentially beneficial therapy. Conclusions: CRAO awareness of the general population and physician awareness about the treatment options as well as the non-standardized prehospital organization, seems to be the main reason for the prehospital delays and impedes treating CRAO patients. Educational efforts should be undertaken to improve awareness about CRAO.

The "Eyelet Sign" as an MRI Clue for Inflammatory Brown Syndrome.

BACKGROUND: Brown syndrome is characterized by a restrictive elevation deficit of the affected eye in adduction. Besides the well-known congenital form, different acquired etiologies including inflammation, trauma, and surgery may prevent the superior oblique (SO) tendon from gliding freely through the trochlea on attempted upgaze. We present MRI findings in pediatric and adult patients with inflammatory acquired Brown syndrome. METHODS: Retrospective review of clinical and MRI findings of 6 patients (4 children: median age 8.4 years [range 6.1-8.7]; 2 adults: age 46.4 and 51.1 years). Median follow-up was 23 months (range 1-52). RESULTS: In all 6 patients, orbital MRI demonstrated inflammatory changes of the SO tendon-trochlea complex. A striking feature was circumferential contrast enhancement of the trochlea with central sparing where the tendon passes, reminiscent of an eyelet. In all cases, the motility restriction improved either spontaneously or with systemic anti-inflammatory treatment. Although both adult patients had a history of known seronegative spondyloarthritis, there was no associated systemic condition in the children in our series. CONCLUSIONS: Both in children and in adults, MRI can provide evidence of inflammatory changes located at the trochlea-tendon complex in acquired Brown syndrome here referred to as the "eyelet sign," which may be helpful in confirming the clinical diagnosis and guide appropriate treatment.

Combined hamartoma of the retina and retinal pigment epithelium - MRI features of a rare paediatric intraocular tumour.

Combined hamartoma of the retina and retinal pigment epithelium is a rare benign ocular tumour in children, composed of glial cells, vascular tissue, and sheets of pigmented epithelial cells. Although generally thought to be congenital, acquired cases are known to exist. It usually presents with reduced visual acuity and/or strabismus and it can be associated with several syndromes, including Neurofibromatosis Type 2. There is no consensus on the management of combined hamartoma of the retina and retinal pigment epithelium. We present a case, including MRI features, of a 4,5-years-old girl with a combined hamartoma of the retina and retinal pigment epithelium.

[Nishida Extraocular Muscle Transposition Surgery for Abducens Nerve Palsy]. / Augenmuskeltransposition nach Nishida bei Abduzensparese.

BACKGROUND: Surgical treatment of abducens nerve palsy depends on the remaining function of the lateral rectus muscle. Vertical rectus transposition surgery is indicated if the attempted maximal abduction effort does not rotate the eye beyond the midline. After the first description more than 100 years ago, a variety of muscle transposition modifications have been suggested. Nishida's minimally-invasive adaptation has attracted a great deal of attention in recent years. PATIENTS AND METHODS: Retrospective case series of four patients with abducens nerve palsy who were treated with Nishida muscle transposition surgery. Patients' characteristics with special emphasis on comparison between pre- and postoperative angle of deviation and ocular motility are reported. RESULTS: Four patients (2 females, 2 males) were included in this study. Unilateral transposition surgery was performed in a 7-year-old girl and a 37-year-old woman with a left abducens nerve palsy. In a 56-year-old male with a left sixth nerve palsy and in an 82-year-old male with a right sixth nerve palsy the transposition maneuver was combined with a recession of the medial rectus muscle in the same eye. In all patients, ocular motility was improved and the angle of deviation was reduced. CONCLUSIONS: Transposition of vertical rectus muscles is well established in the surgical treatment of abducens nerve palsy. Nishida's adaptation is a safe, effective and minimally-invasive treatment option. This vessel-sparing technique also allows for equilateral weakening of the medial rectus muscle.

[Prism-Induced Gaze Shift and Strabismus Treatment for Ocular Motility Disorders and Anomalous Head Posture]. / Prismen zur Blickverlagerung und Schielkorrektur bei Augenmotilitätsstörungen und Kopfzwangshaltung.

BACKGROUND: The therapeutic treatment of ocular motility disorders and anomalous head postures (AHP) is often challenging. We report our experience with prism use in these patients. PATIENTS AND METHODS: Retrospective case series of three patients with ocular motility disorders and associated AHP who were treated with prism correction. RESULTS: A 37-year-old male with a traumatic left oculomotor nerve palsy suffered from a residual minor depression deficit and a severe elevation palsy. With OS: 10^ base-up he was corrected for left hypotropia only in down gaze. Ten yoked prisms base-up shifted the field of binocular single vision in primary position. A 45-year-old male with traumatic Parinaud syndrome and upward gaze palsy suffered from neck pain due to his pronounced chin elevation. He also had a right amaurosis with secondary exotropia. With OS: 8^ base-up, his AHP was corrected and his neck pain was alleviated. A 69-year-old woman with a left abducens nerve palsy adopted a left turn of 20° to compensate for her deviation in extreme right gaze. With OS: 20^ base-out, her AHP was corrected and she experienced no double vision in primary position. CONCLUSIONS: Prisms are used to correct strabismic deviations but also can successfully shift images towards another gaze in different clinical scenarios. Reduction of AHP, therefore, can be obtained by a prism-induced gaze shift in the direction of the motility restriction.

Optic Disc Features in Familial Retinal Arteriolar Tortuosity.

PURPOSE: Describing optic disc appearance in familial retinal arteriolar tortuosity (fRAT) using multimodal imaging and raising awareness of peripapillary arterial changes due to this disorder. METHODS: A cross-sectional study was performed in four consecutive patients of two non-related families. Detailed ophthalmological examination was performed and supported by medical and family history and multimodal imaging. RESULTS: In all subjects, increased tortuosity of second- and third-order retinal arteries in superior and deeper vascular plexus was documented. Furthermore, tortuosity in the peripapillary circle of Zinn-Haller was found. In addition, retinal vessel oximetry confirmed tortuosity only of the arterial vessels. CONCLUSION: The present data suggests that a blurry bordered, hyperemic optic disc in the presence of abnormally tortuous arteriolar vessels and asymptomatically or oligosymptomatically spontaneously resolved hemorrhages could be associated with a fRAT. This finding could be linked to peripapillary arterial vessel tortuosity.

Yokoyama procedure for esotropia associated with high myopia: real-world data from a large-scale multicentre analysis.

PURPOSE: High myopic patients may develop strabismus due to globe dislocation out of the normal extraocular muscle cone. Surgical correction of this strabismus type is possible by joining the superior and lateral rectus muscles without the need for a scleral suture called the Yokoyama procedure. Data from large patient samples and the evaluation of a potential effect of an additional medial rectus recession (MRR) have been lacking so far. METHODS: We pooled retrospective patient data of 14 departments of ophthalmology in Germany and Switzerland and analysed determinants of postoperative results using multivariable regression models. RESULTS: We included 133 patients (mean age: 59.7 ± 13.4 years, surgery between 2008 and 2017) with a mean preoperative esotropia (both Yokoyama with and without MRR) of 23.8°±4.6°. The angle of preoperative esotropia increased with age. The postoperative esotropia was 8.7° ± 9.9°, and six patients were overcorrected. While preoperative esotropia was highly associated with postoperative results, we found no association of additional MRR with any of our postoperative outcome measures. The Yokoyama procedure had a higher absolute effect in patients with higher preoperative esotropia. CONCLUSION: Our study confirms the positive effect of the Yokoyama procedure on strabismus due to high myopia in large-scale real-world data. In some cases, MRR may be needed because of muscle contracture, although additional MRR statistically did not affect the postoperative outcome. In patients with bilateral high myopic strabismus, correction of both eyes seems beneficial. The effect size of the Yokoyama procedure appears to be mainly driven by preoperative esotropia.

The Role of Time Exposed to Outdoor Light for Myopia Prevalence and Progression: A Literature Review.

PURPOSE: The development of myopia as a refractive disorder seems to hold multifactorial causes. Among others, increased time exposed to natural light outdoors is regarded as possible effective preventive measure against myopia development. The objective of this review is to analyse and summarize the evidence investigating the association between time outdoors and myopia prevalence and progression. METHODS: A review, restricted to articles published in the last ten years, was conducted. The literature search for the included articles was performed in the following databases: PubMed, the Cochrane Library, Web of Science and Scopus. If predefined inclusion criteria were met, the studies were further categorized and data were summarized and individually evaluated. RESULTS: Two cross-sectional studies, 7 prospective cohort studies and 3 intervention studies were reported in this review, representing the data of a total of 32,381 participants. The majority of the studies found an inverse association between myopia incidence/prevalence and increased time outdoors. The association between time outdoors and myopia progression on the other hand remains debatable; one recent randomized controlled trial indicating a protective value of increased time outdoors for further progression in myopic children. CONCLUSION: In summary, increasing time exposed to outdoor light seems to be a simple and effective preventive measure to decrease myopia prevalence. Also, contrasting previous review work, it may represent a potential strategy for myopia progression control. Future investigation is necessary to better define and quantify outdoor time and its effects on myopia.

[Ocular Motor Nerve Palsies Caused by Paragliding Accidents]. / Augenmuskelparesen nach Gleitschirmunfällen.

BACKGROUND: Paragliding is a risk-taking adventure sport. It can be performed either individually or accompanied by a pilot in tandem formation. Paragliding, as well as other types of "extreme" sport, have gained popularity over the past few years. Injuries predominantly involve the lower extremities and the spinal column. Head injuries occur only rarely. PATIENTS AND METHODS: Retrospective case series of three patients with ocular motor nerve palsies caused by paragliding accidents. Patients' characteristics with special emphasis on treatment strategies are reported. RESULTS: Two men (41 and 56 years of age) suffered from open head injuries and one 56-year-old male from a closed head injury as part of polytrauma caused by paragliding accidents. All patients complained of double vision. The first patient showed a right abducens nerve palsy and elevation deficit due to a complex orbital fracture. Patient 2 had a traumatic right six nerve palsy. The third patient had a complex motility disorder with a bilateral abducens and trochlear nerve palsy. In all three cases, eye muscle surgery improved ocular motility. Two patients regained binocular single vision. CONCLUSIONS: Characteristics of injuries caused by paragliding accidents depend on the trauma scenario. Injury pattern might differ widely. Ocular motor nerve palsies often accompany head trauma. Treatment is guided by common strategies for incomitant strabismus. These ocular motility disorders are often complex and require an individually tailored approach.

First Clinical Experience with Anti-myelin Oligodendrocyte Glycoprotein Antibody-Positive Optic Neuritis.

BACKGROUND: Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) have been consistently found in a range of demyelinating disorders. In this context, MOG-IgG-associated optic neuritis (ON) has been suggested as a new subset of optic neuropathy. However, clinical manifestations and distinctive characteristics have only rarely been described. PATIENTS AND METHODS: A retrospective case series of three patients with MOG-IgG-associated ON. Clinical morphological features using imaging techniques are presented. RESULTS: Three patients (8-year-old boy, 28-year-old female, 48-year-old male) were included. An 8-year-old boy suffered from a bilateral ON with severe visual loss. The best-corrected visual acuity (BCVA) was 0.05 in the right eye and finger counting in the left eye. The patient had a previous episode of acute disseminated encephalomyelitis (ADEM) with a right abducens nerve palsy. Visual acuity recovered after repeated cycles of intravenous methylprednisolone pulse therapy and 10 cycles of plasma exchange. During the last follow-up, BCVA was 0.9 in the right eye and 0.8 in the left eye. A 28-year-old female presented with a bilateral ON. Her BCVA was 0.5 in the right eye and 0.8 in the left eye. She fully recovered with pulse methylprednisolone therapy (1000 mg/d) with tapering after the second cycle and had a BCVA of 1.0 during the last follow-up visit. A 48-year-old male suffered from a relapsing bilateral ON. At first presentation, BCVA was 0.1 in the right eye and finger counting in the left eye. BCVA fully recovered after each pulse therapy with intravenous methylprednisolone (two cycles). Since the first relapse, the patient has been receiving long-term immunosuppression with rituximab. Despite rituximab and low-dose oral prednisone, the patient had another relapse with a left ON. After a third cycle with intravenous methylprednisolone, he partially recovered. BCVA at last follow-up was 1.0 in the right and 0.8 in the left eye. CONCLUSIONS: MOG-IgG antibodies have been identified in different acquired demyelinating syndromes. The patients reported had an ADEM followed by bilateral ON, an isolated bilateral ON, and a relapsing bilateral ON. Individual treatment strategies led to substantial visual recovery in all patients. We recommend inclusion of MOG-IgG antibodies in the diagnostic workup at least after the first recurrence of ON since they can serve as a diagnostic and potential prognostic tool and might lead to specific therapeutic recommendations.

Combined pars plana vitrectomy with phacoemulsification for rhegmatogenous retinal detachment repair.

PURPOSE: To investigate the outcome after combined phaco-vitrectomy in rhegmatogenous retinal detachment (RRD) repair. PATIENTS AND METHODS: In this retrospective study, we included all patients who underwent pars plana vitrectomy (PPV) for RRD between January 2013 and December 2017. The main outcome measure was the retinal re-detachment rate after combined phaco-vitrectomy. RESULTS: Overall, 1017 eyes with RRD were included. All eyes received PPV, while in 516 eyes additional phacoemulsification was performed. A retinal re-detachment occurred in 103 patients (10.1%). No significant difference in the rate of re-detachment was found if additional phacoemulsification was performed (p=0.641). Subgroup calculations showed a significant higher rate of re-detachment in patients with a PVR (p=0.0003) and in patients where silicone oil was used as primary tamponade (p=0.0001) as well as in macula off RRDs (p=0.034). CONCLUSION: Additional phacoemulsification during vitrectomy for RRD is not associated with higher rate of retinal re-detachment.

[Acute Macular Neuroretinopathy]. / Akute makuläre Neuroretinopathie.

BACKGROUND: Acute macular neuroretinopathy (AMNR) is a rare unilateral or bilateral macular disorder. It typically occurs in young women presenting with sudden onset of central scotomas. They correspond to sharp reddish-brown areas in the macular region. The lesions often can only be observed with infrared reflectance imaging. These flat oval or wedge-shaped lesions are often grouped as a flower around the fovea. PATIENTS AND METHODS: Retrospective case series of 4 patients with AMNR. Clinical morphological features using different imaging techniques are presented. RESULTS: Four young women (26, 27, 28, 29 years of age) complained of seeing dark spots in the central visual field. In 3 patients, the scotomas occurred bilaterally. Three patients reported a history of preceding flu-like illness. In all 4 cases, visual acuity in both eyes was 1.0 with normal anterior and posterior segments. The corresponding retinal lesions were only noted in the infrared image of the optical coherence tomography (OCT). OCT images showed focal abnormalities in the photoreceptor outer segments. Follow-up periods varied between 9 and 36 months. In all patients, symptoms improved with at least partial recovery of the retinal architecture. CONCLUSIONS: Patients with AMNR suffer from acute onset of unilateral or bilateral central scotomas. Visual acuity is often only mildly affected. AMNR has a variable prognosis. In some cases, a self-limiting course with retinal recovery is observed while some patients have persistent reduction in visual acuity. Because there is no causative treatment for AMNR, an observational treatment approach is generally recommended.

Vision Screening in Children in the Canton of St. Gallen.

BACKGROUND: Pediatric vision screening has been shown to reduce the prevalence of amblyopia. To assess the current local situation in the Canton of St. Gallen, a survey study was performed. METHODS: A standardized questionnaire was sent to 191 general practitioners and school doctors to obtain information on the currently applied vision screening protocols for children. The questionnaire included 17 questions with multiple answers possible. RESULTS: Sixty-seven participants (35%) answered the survey. Overall, 61 (91%) of the repliers confirmed that some sort of vision screening exists. According to 45 (67%) repliers, a mandatory examination exists. As to the question about the person performing the examination, multiple answers were given; 39 (44%) answered that the secretary or the medical practical assistant performs the vision tests, 15 (17%) indicated the school doctor, and 25 (28%) indicated the general practitioner or the pediatrician. Most screening tests are performed in a general practitioner's practice (32; 40%), some are done in the kindergartens (17; 21%), and others are done in a pediatrician's practice (17; 21%). The majority of children are tested at the age of 5 - 6 years (58, 87%). Sixty-one (91%) of the repliers indicated that at least the children's visual acuity is measured. Acuity is assessed with different methods, mainly, with pictures (20; 30%), numbers (23; 34%), and Snellen optotypes (33; 49%). CONCLUSIONS: There are no consistent regulations regarding vision screening in the Canton of St. Gallen. Actually, rather different screening scenarios exist. Tests are performed by a variety of people in different locations with diverse testing procedures. A standardization of the applied screening procedures at cantonal and national levels seems reasonable.

[Assessment of Cyclofusion Capabilities of Normal Subjects with 3D Dynamic Random-Dot Stereograms]. / Messung der Zyklofusionskompetenz bei Normalprobanden mittels dynamischer 3-D-"Random-Dot"-Stereogramme.

BACKGROUND: Evaluation of a new method for cyclofusion measurement. PATIENTS AND METHODS: The maximal incyclofusion and excyclofusion tolerated of 20 normal subjects (15 females, mean age 36 ± 9.9 years) were measured by computer-generated dynamic random-dot stereograms (DRDS). Subjects had to detect the orientation of only binocularly visible Landolt C stimuli randomly presented with a 3-D monitor. Both eyes were separately stimulated with shutter glasses. The DRDS-pattern projected to the left and right eye were rotated in the opposite direction in 0.5° steps. In 10 subjects, cyclofusion measurements were repeated. RESULTS: Incylofusional amplitudes were between 2.5° and 6°, excyclofusional amplitudes measured between 3° and 5.5°. Mean incyclofusion was 3.71° (SD 0.82) and mean excyclofusion measured 4.24° (SD 0.73). Repeated measurements of incyclofusion and excyclofusion in the same subject demonstrated a difference of about 0.5° (0.55° for incyclofusion, 0.45° for excyclofusion). CONCLUSIONS: The DRDS Landolt C method provided a reliable assessment with good reproducibility of cyclofusion in healthy subjects with only binocularly perceivable objects. Our cyclofusional capabilities were slightly higher than those received with dissociating 2D measurements.