Effectiveness of Strabismus Surgery in Intermittent Exotropia and Factors Influencing Outcome.

Intermittent exotropia (IXT) is known to relapse after surgery. No factors to predict or prevent recurrence are known with certainty. This study investigated surgical outcome, potential influencing factors, and reoperation rate in patients with IXT. Medical records of 537 patients who underwent surgery for IXT from 2000 to 2022 with preoperative angles of exodeviation of 6 to 50 prism diopters (PD) were retrospectively studied. Multivariate regression analyses of factors influencing surgical outcome on postoperative day 1 (POD1) and reoperation rate were performed. A Kaplan-Meier analysis was performed to illustrate the reoperation rate. After the first surgery, 83.8% of patients had a successful surgical outcome on POD1 (esodeviation ≤ 5 PD or exodeviation ≤ 10 PD). Logistic regression analysis revealed that small preoperative angles of exodeviation increased the probability for surgical success. Follow-up data at different times (4 days-20 years) after surgery were available for 176 patients: 40 patients were still in the range of surgical success, 133 patients had exotropia > 10 PD. Of the follow-up patients, 65 (12.1%) underwent reoperation. A total of 8.5% had their reoperation within one year after the first surgery, 52.9% within five years. Cox regression analysis revealed that large preoperative angles of exodeviation, far/near incomitance and alphabet pattern strabismus increased the risk of reoperation. Most patients achieved surgical success on POD1, yet the squint angles often increased after surgery, resulting in reoperation in some patients. Prospective studies are needed for a better assessment of pre-, peri- and postoperative factors for surgical success in IXT.

[Brown's atavistic superior oblique syndrome: etiology of different types of motility disorders in congenital Brown's syndrome]. / Atavistischer Obliquus-superior-Brown-Syndrom: Ätiologie der verschiedenen Arten von Motilitätsstörungen beim kongenitalen Brown-Syndrom.

CLINICAL FEATURES: The congenital Brown syndrome is characterized by a mechanical limitation of elevation in adduction, with an orthophoria in down gaze. Brown postulated a shortened superior oblique tendon sheath as the cause of the limitation but this was disproved by Parks et al. in 1975 and the origin of Brown syndrome remains unclear. In recent years, a congenital dysinnervation has been discussed; however, this does not explain the full spectrum of abnormalities and especially contradicts the unlimited depression in adduction seen in Brown syndrome. ORIGIN: Surgical exploration in Brown true typical cases reveals a fibrotic strand, typically located at the posterior margin of the superior oblique tendon. This strand originates from the trochlear area and has a common insertion with the superior oblique tendon posterior to the equator into the globe. It may represent an atavistic superior oblique muscle as described by Fink in various animals. They do not have a trochlea but a superior oblique muscle originating in the anterior superior nasal orbit. ATYPICAL BROWN SYNDROME: A fibrotic strand was also surgically revealed in two cases of atypical Brown syndrome. In the first case an elevation deficit-as in Brown true atypical cases-also present in abduction could be explained by an unusual insertion of the fibrotic strand anterior to the equator. The second case showed a fibrotic strand which was completely separated from the superior oblique tendon and inserted far posterior to the equator nasal to the superior rectus muscle. This finding had not been previously described and explained the total elevation restriction which was suddenly in > 30° adduction and the Y­pattern exotropia which increased in adduction and decreased in abduction. TREATMENT AND FOLLOW-UP: A 10 mm excision of the fibrotic strand from the insertion gives the best results from all procedures. The residual limitation of active elevation in adduction improved with gaze exercises mostly after more than 1 year. CONCLUSION: The fibrotic strand, an atavistic superior oblique muscle, not only explains the typical Brown syndrome but also-by its variable insertion-different patterns of elevation deficits seen in atypical Brown syndrome. A 10 mm excision of the strand gives good functional results of abnormal head position (immediate in most cases) and even elevation in adduction (after 1 year in most cases).

Extraocular muscles involved in convergence are innervated by an additional set of palisade endings that may differ in their excitability: A human study.

Palisade endings are located at the myotendinous junction of extraocular muscles in most mammals. Irrespective of their unclarified function as motor or sensory nerve endings, a specialized role in convergence is proposed, based on their high number in the medial rectus muscle (MR). Further support comes from a study in monkey demonstrating that only the MR and inferior rectus muscle (IR) contain an additional population of palisade endings that express the calcium-binding protein calretinin (CR) in addition to choline acetyltransferase (ChAT). Here we studied, whether CR-positive palisade endings are present in human as well and confined to extraocular muscles most active during convergence. The systematic analysis of all eye muscles of 17 human specimen revealed that only the MR and IR contain an additional population of CR-positive palisade endings and multiple en-grappe endings, which target non-twitch muscle fibers along their whole length. Approximately 80% of all palisade endings in the MR expressed CR. Furthermore, the intrafusal muscle fibers of some muscle spindles in the MR were innervated by CR-positive annulospiral nerve endings that transmit the signals of muscle length changes to the brain. All extraocular muscles contained few thin CR-positive, but ChAT-negative nerve fibers, possibly representing free sensory or autonomic endings arising from the trigeminal ganglion. As in monkey, in the medial periphery of the human oculomotor nucleus ChAT-positive neurons were found to co-express CR. Therefore these neurons most likely represent the cell bodies of CR-positive palisade endings in the MR. Unlike in monkey, these neurons do not lie within a compact cell group, but are more scattered. In conclusion, the MR and IR in human contain two histochemically different populations of palisade and multiple endings that may contribute to ocular alignment and convergence in a different way.

Reversible benign intracranial hypertension in a child with hyperthyroidism.

Endocrine dysfunction is a rare but known cause of benign intracranial hypertensio (BIH) in adults. Here we describe a rare case of BIH in the pediatric age group associated with autoimmune hyperthyroidism. A 12-year-old girl presented with a 3-month history of headaches. Ophthalmic examination revealed bilateral papilledema. The ocular findings were otherwise normal, with no exophthalmos. Cranial and orbital magnetic resonance imaging was unremarkable. Lumbar CSF opening pressure in recumbent and relaxed position was elevated (31 cm water). Thyroid hormones fT3 and fT4 were elevated while TSH was completely suppressed. As TSH receptor stimulating antibodies (TSHR-Ab) were elevated Graves' disease was diagnosed. Thyroid suppressive therapy with carbimazole was initiated and supplemented by propranolol. As hyperthyroidism improved over two weeks the headaches subsided and the papilledema slowly resolved over the next 2 months. This case illustrates that hyperthyroidism should be considered as a cause of BIH in children.

Comparing Alternative Ranibizumab Dosages for Safety and Efficacy in Retinopathy of Prematurity: A Randomized Clinical Trial.

Importance: Anti-vascular endothelial growth factor (VEGF) therapies are a novel treatment option in retinopathy of prematurity (ROP). Data on dosing, efficacy, and safety are insufficient. Objective: To investigate lower doses of anti-VEGF therapy with ranibizumab, a substance with a significantly shorter systemic half-life than the standard treatment, bevacizumab. Design, Setting, and Participants: This randomized, multicenter, double-blind, investigator-initiated trial at 9 academic medical centers in Germany compared ranibizumab doses of 0.12 mg vs 0.20 mg in infants with bilateral aggressive posterior ROP; ROP stage 1 with plus disease, 2 with plus disease, or 3 with or without plus disease in zone I; or ROP stage 3 with plus disease in posterior zone II. Patients were recruited between September 2014 and August 2016. Twenty infants were screened and 19 were randomized. Interventions: All infants received 1 baseline ranibizumab injection per eye. Reinjections were allowed in case of ROP recurrence after at least 28 days. Main Outcomes and Measures: The primary end point was the number of infants who did not require rescue therapy at 24 weeks. Key secondary end points included time-to-event analyses, progression of physiologic vascularization, and plasma VEGF levels. Stages of ROP were photodocumented and reviewed by an expert committee. Results: Nineteen infants with ROP were enrolled (9 [47.4%] female; median [range] postmenstrual age at first treatment, 36.4 [34.7-39.7] weeks), 3 of whom died during the study (1 in the 0.12-mg group and 2 in the 0.20-mg group). Of the surviving infants, 8 (88.9%) (17 eyes [94.4%]) in the 0.12-mg group and 6 (85.7%) (13 eyes [92.9%]) in the 0.20-mg group did not require rescue therapy. Both ranibizumab doses were equally successful in controlling acute ROP (Cochran-Mantel-Haenszel analysis; odds ratio, 1.88; 95% CI, 0.26-13.49; P = .53). Physiologic intraretinal vascularization was superior in the 0.12-mg group. The VEGF plasma levels were not systematically altered in either group. Conclusions and Relevance: This pilot study demonstrates that ranibizumab is effective in controlling acute ROP and that 24% of the standard adult dose (0.12 mg) appears equally effective as 40% (0.20 mg). Superior vascularization of the peripheral retina with 0.12 mg of ranibizumab indicates that the lower dose may be favorable. Unchanged plasma VEGF levels point toward a limited systemic drug exposure after ranibizumab. Trial Registration: clinicaltrials.gov Identifier: NCT02134457 and clinicaltrialsregister.eu Identifier: 2013-002539-13.

Screening for refractive errors in preschool children with the vision screener.

BACKGROUND: The Vision Screener is a new, commercial version of the Power Refractor, an off-axis, hand-held video refractor to screen for amblyogenic refractive errors. The aim of our study was to determine the reproducibility of the measurements, compare them to cycloplegic refraction, and evaluate the sensitivity and specificity for the detection of amblyogenic refractive errors. PATIENTS AND METHODS: Included in the study were 161 preschool children, age 0.5-7.2 years without manifest strabismus > 10 degrees , who attended the outpatient clinic. After three measurements with the Vision Screener (version 4.3.15) and one measurement with +3 dpt glasses, the child underwent cycloplegic refraction. RESULTS: The reproducibility of the three non-cycloplegic measurements was +/- 0.5 dpt in 85% and +/- 1 dpt in more than 95% of the children. Accommodation reduced the manifest hyperopia that could be measured with the Vision Screener by up to 3 dpt in some children. Compliance with the +3 dpt glasses increased from 20% in those under one year of age to > 75 % in those over three. The glasses did increase the sensitivity from 70% to 80% but decreased the specificity from 80% to 65%. CONCLUSION: The Vision Screener is easy to handle and gives reproducible results. The sensitivity and specificity are between 70 and 80%. The +3 dpt glasses are only helpful in a few patients. The latest software version with a new algorithm is now under evaluation.

Pediatric idiopathic intracranial hypertension - Is the fixed threshold value of elevated LP opening pressure set too high?

BACKGROUND: Idiopathic intracranial hypertension (IIH) in children is a rare condition of unknown etiology and various clinical presentations. The primary aim of this study was to evaluate if our pediatric IIH study group fulfilled the revised diagnostic criteria for IIH published in 2013, particularly with regard to clinical presentation and threshold value of an elevated lumbar puncture opening pressure. Additionally we investigated the potential utilization of MR-based and fundoscopic methods of estimating intracranial pressure for improved diagnosis. PATIENTS AND METHODS: Clinical data were collected retrospectively from twelve pediatric patients diagnosed with IIH between 2008 and 2012 and revised diagnostic criteria were applied. Comparison with non-invasive methods for measuring intracranial pressure, MRI-based measurement (MR-ICP) and venous ophthalmodynamometry was performed. RESULTS: Only four of the twelve children (33%) fulfilled the revised diagnostic criteria for a definite diagnosis of IIH. Regarding noninvasive methods, MR-ICP (n = 6) showed a significantly higher mean of intracranial pressure compared to a healthy age- and sex-matched control group (p = 0.0043). Venous ophthalmodynamometry (n = 4) showed comparable results to invasive lumbar puncture. CONCLUSION: The revised diagnostic criteria for IIH may be too strict especially in children without papilledema. MR-ICP and venous ophthalmodynamometry are promising complementary procedures for monitoring disease progression and response to treatment.

Integration of orientation information in amblyopia.

A recent report suggests that amblyopes are deficient in processing local orientation at supra-threshold contrasts. To determine whether amblyopes are also poor at integrating local orientation signals, we assessed performance for an orientation integration task in which the orientations of static signals are integrated across space. Our results show that amblyopic visual systems can integrate local static oriented signals with the same level of efficiency as normal visual systems. Although internal noise was slightly elevated, there was no indication that fewer samples were used to achieve optimal performance. This finding suggests normal integration of local orientation signals in amblyopia.

Effect of inferior oblique recession in strabismus sursoadductorius.

UNLABELLED: The aim of this retrospective study was a quantitative analysis of the effect of graded inferior oblique recessions (8 mm, 10 mm or maximal) in strabismus sursoadductorius. METHOD: 234 patients (2-81 years of age) with unilateral strabismus sursoadductorius and stereopsis were operated between 1990 and 1999. Maximal recession (14.6 mm) included an anteroposition to the lateral aspect of the insertion of the inferior rectus. Before and three months after the operation, horizontal and vertical deviations (VD) were assessed by cover testing in five positions of gaze. In 121 patients, additional subjective quantitative assessment, including cyclodeviation measurement, was carried out with Harms' tangent screen. RESULTS: The mean effect of the operation on VD in 25 degrees adduction increased from 6 degrees with 8 mm recession to 10 degrees with maximal recession. It was related more to the amount of preoperative VD in adduction than to the amount of recession. One patient had a limitation of elevation with a hypotropia of >4 degrees, 7% needed further surgery because of undercorrection. DISCUSSION: Maximal recession of the inferior oblique muscle is a suitable procedure even in patients with marked strabismus sursoadductorius. The rate of functional undercorrection is low and there is no risk from general anesthesia or significant postoperative limitation of elevation.

Infantile and acquired nystagmus in childhood.

Nystagmus is an involuntary, periodic eye movement caused by a slow drift of fixation which is followed by a fast refixation saccade (jerk nystagmus) or a slow movement back to fixation (pendular nystagmus). In childhood most cases are benign forms of nystagmus: idiopathic infantile, ocular or latent nystagmus. They arise at the age of 3 months, without oscillopsia and show the absence of the physiologic opto-kinetic nystagmus. A full ophthalmologic evaluation is all that is needed in most cases: albinism, macular or optic nerve hypoplasia and congenital retinal dystrophies are the most common forms of ocular nystagmus. Idiopathic infantile nystagmus can be hereditary, the most common and best analyzed form being a mutation of the FRMD7 gene on chromosome Xq26.2. The mutation shows a mild genotype-phenotype correlation. In all female carriers the opto-kinetic nystagmus is absent and half had mild nystagmus. Latent nystagmus is part of the infantile esotropia syndrome and shows the unique feature of change of direction when the fixing eye changes: it is always beating to the side of the fixing eye. There is no cure for infantile nystagmus but therapeutic options include magnifying visual aids or eye muscle surgery at the age of 6-8 y in patients with head turn. Less than 20% of childhood nystagmus are acquired and need further neurological and imaging work-up. Alarming signs and symptoms are: onset after the age of 4 months, oscillopsia, dissociated (asymmetric) nystagmus, preserved opto-kinetic nystagmus, afferent pupillary defect, papilloedema and neurological symptoms like vertigo and nausea. The most common cause is due to pathology of the anterior optic pathway (e.g. optic nerve gliomas). It shows the same clinical feature of dissociated nystagmus as spasmus nutans but has a higher frequency as in INO. Other forms of acquired nystagmus are due to brainstem, cerebellar or metabolic diseases.

Foveal contour interaction: detection and discrimination.

Contour interaction, the detrimental effect of flanking features on the discrimination of optotypes, has been studied mainly close to the visual acuity limit. We were interested to know how these results compare with those for the detection of targets. According to the simplest model of contour interaction, comparable detection effects would be expected. The case for low-level masking would be further strengthened if the form and nature of the dependence on flank separation and flank polarity followed that typically found in studies of lateral spatial masking [Vision Res. 33, 993 (1993)]. Landolt Cs subtending a visual angle of 0.25 degrees, 0.5 degrees, and 1.0 degrees were presented and contrast thresholds for detecting the presence of the Landolt C and discriminating its orientation were measured in five normal subjects as a function of flank separation and flank polarity. The results obtained for the relationship between detection and discrimination depend on the size of the target used. For small letters, discrimination but not detection was significantly affected by flanking bars. For large letters, detection and discrimination were affected to the same extent. However, in this case the effectiveness of opposite-polarity flanks and the finding that facilitation occurred at close, not far, flank separations suggests that the simplest explanation in terms of masking may not be applicable.

[Application of the new coding standards for introducing diagnosis related groups (DRGs) in ophthalmology]. / Anwendung der neuen Kodierrichtlinien für die Einführung von Diagnosis Related Groups (DRGs) in der Augenheilkunde.

For all in-patients a fundamental change of hospital financing based only on diagnosis related groups (DRGs) is planned in Germany for 2004. Patients are grouped into different DRGs according to their coded diagnoses, operations and procedures. Hence, the quality of coding is essential for adequate reimbursement of cases and thus for hospital financing. The legal framework of coding is supplied by the so-called "general and special coding guidelines for coding diseases and procedures", presented jointly by the associations representing hospitals and public and private health insurance companies in early 2002. These German coding standards regulate how coding must be performed in daily practice and therefore have a major influence on the grouping of patients into DRGs. Because of their importance this paper describes the practical application of current coding standards. Specifically in Ophthalmology the problem exists that for many procedures adequate coding numbers are still missing, thus impairing further development of the DRG system.

Foveal contrast thresholds exhibit spatial-frequency- and polarity-specific contour interactions.

Traditionally, contour interaction has been investigated at the visual acuity limit using a Landolt C and flanking bars, performance being quantified in terms of a percent correct measure. More recently, it has been shown that the properties of the contour interaction are different when larger stimuli are used: Contour interaction is not polarity specific, and spatial frequency tuning for an unflanked C is broader. Here we quantify contour interaction for stimuli 5x larger than the resolution limit in terms of contrast thresholds. We show that polarity of bars has little effect on unfiltered stimuli but does show very different effects on the spatial-frequency-tuning curves for discrimination of the Landolt C. This explains the polarity dependence of crowding at the visual acuity limit and its independence for larger unfiltered targets. Thus the underlying filtering function is composed of more than one mechanism, affected differently depending on the relative polarity of the test and flank contours.

Orbital rhabdomyosarcoma in Noonan syndrome.

The incidence of various benign and malignant tumors is increased in patients with Noonan syndrome compared with the general population. We present a 9-year-old boy with the typical features of Noonan syndrome and an acute nonaxial proptosis of the right eye. An ultrasound scan, a computed tomography scan, and magnetic resonance imaging raised suspicion of rhabdomyosarcoma. Biopsy confirmed the diagnosis. The tumor was consequently treated with combined chemotherapy and radiotherapy. Rhabdomyosarcoma is a rare but important differential diagnosis of tumor formation in children with Noonan syndrome and may arise in the orbit.