Binocular vision & strabismus quarterly最新文献

Introduction: Historical systems of measuring the amount of surgical recession of the medial rectus muscles appropriate to be performed for a given size of angle of infantile esotropia, based upon relative recession measurement from the limbus might have proven to be better than relative recession measurement from the insertion--if a positive correlation were found between the size of the angle of the esodeviation and the distance between the insertion of the medial rectus and the nasal limbus. A search of the scientific literature since 1966 as listed in PubMed (National Library of Medicine, formerly Index Medicus) did not reveal any additional confirmatory study of this type in PubMed. We therefore undertook to perform such a study.

Methods: Using standard strabismus calipers, at surgery for esotropia, intraoperative measurements were made of the insertional distance (in mm between the most nasal point of the clear cornea and, following standard surgical excision of the muscle from the globe, the anterior insertional ridge of the medial rectus muscle of the eye) in a series of 104 consecutive infantile esotropes operated by the author between 1987 and 1991. These data were then graphically plotted as the ordinate with the abscissa defined as the size of the angle of the esotropia measured with the prism alternate cover test the day prior to surgery.

Results: No correlation was found between the medial rectus muscle insertional distance and the size of the preoperative esodeviation in prism diopters, correlation coefficient r=0.14, p=0.078. DISCUSSION OF RESULTS: In this large series, the lack of a correlation has credibility as it fails to achieve conventional limits of a "statistical significance" of the difference.

Conclusion: The lack of correlation between the size of the deviation and the insertional distance offers support for the widespread acceptance and use of the alternative, the dose-response curves based on the mm of recession measured from the anterior ridge of the medial rectus muscle insertion.

Introduction: Strabismus has been previously reported as a rare presenting feature of the Type 1 Chiari malformation.

Case reports: We report a case series of twelve patients with Chiari 1 malformations with either strabismus or diplopia as part of their initial presentation. Ten patients had diplopia at the time of presentation, while 2 young children (ages 2 and 6) presented with esotropia without complaints of diplopia. Of the 10 patients with diplopia, 7 were constantly or frequently tropic while 3 had symptomatic phorias. One or more unusual features of the strabismus led to further investigations and the diagnosis of Chiari in these patients. The most common oculomotor disturbance was a comitant esotropia. Most patients were managed with prism glasses. One patient had strabismus surgery as primary treatment with early orthotropia. Three patients underwent neurosurgical decompression, with minimal improvement of their strabismus; one of these underwent subsequent successful strabismus surgery.

Conclusions: Chiari 1 malformation may present with strabismus or diplopia as the major finding. Associated neurological features may be nonspecific (e.g., headache), subtle (e.g., gaze-evoked nystagmus), or delayed. Although neurosurgery may be required in some cases, primary strabismus management (surgical or prismatic correction) can be successful, particularly when strabismus is the lone (or sole specific) finding.

Purpose: To establish the utility of a video-oculography system (3D-VOG) in the diagnosis of a patient with difficult idiopathic vertical diplopia.

Case report: We present a clinical case of an 87 year old female who was operated for glaucoma and cataract with the intracapsular technique in both eyes. She reported vertical diplopia with the use of contact lenses but not while using her aphakia spectacles. A complete ophthalmological study was carried out with special interest in the ocular motility study with 3D-VOG.

Results: Besides the hypertropia in lateroversion of the non-fixing eye, the video-oculography showed an incyclotorsion of the hypertropic eye, a fundamental factor for the differential diagnosis between bilateral superior oblique overaction and DVD or dissociated vertical divergence. Such a torsional strabismic deviation is very difficult to detail by other methods and is the important clue for diagnosis. The 3D-VOG made this diagnosis possible.

Conclusions: The occurrence of a vertical diplopia with use of contact lenses, and not with spectacles, is explained by the limitation of ocular gaze movements with the aphakia spectacles which limitation is not found with the use of contact lenses, with diplopia appearing in the more extreme lateroversion possible with the contact lenses. The 3D-VOG system enabled us to analyze torsional movements in lateroversion that allowed the diagnosis of bilateral superior oblique overaction to be made.

Background: Microtropia is under diagnosed in treated esotropia and in primary microtropia cases, where patients are young and uncooperative.

Method: Video Vision Development Assessment (VVDA) testing, which we have developed and previously described, captures multiple video frames images (30 per second) of the Breuckner red reflection (from the ocular fundus, a test for strabismus and ocular media abnormalities) combined with eccentric photorefraction. This method allows the highly critical discrimination of minimally off axis fixation (abnormal) to be differentiated from true on axis fixation (normal foveation) by the brightness difference in the images. We have examined with this method, VVDA, 533 consecutive strabismus patients ages six months to six years.

Results: 47% of esotropes and 23.8% of exotropes had microtropia.

Conclusion: VVDA is helpful in documenting microtropia in young uncooperative patients where the diagnosis may otherwise be missed, even when suspected to be present, due to lack of subjective test cooperation. Multiple video frames of the same patient (VVDA) allow dynamic detection of true fixation (normal foveation) versus slightly off axis fixation (abnormal, consistent with microtropia). VVDA is therefore superior to single photorefraction imaging in the diagnosis of microtropia.

Background: Double Elevator Palsy (DEP) was originally given its name because the assumption was, that because the affected eye could not elevate in adduction or in abduction, there must be a paresis of both the Superior Rectus (SR) and the Inferior Oblique (IO). Later, it was thought that DEP was due to a paresis of the ipsilateral SR, since the SR is the main elevator of the eye in both adduction and abduction. Gradually, a group of observations accumulated that indicated that the SR was not paretic at all in DEP, leading to the concept that DEP is due to a unilateral deficit in a nucleus that functions to elevate one eye only, a unilateral center for upgaze. The purpose of this paper is to report a clinical case with findings that further support this last hypothesis.

Case report: A 15 month old girl presenting with classical signs of DEP of the left eye received a 6 mm recession of the left Inferior Rectus (IR). This was insufficient to eliminate a large chin elevation and a 9 prism diopter left hypotropia in the primary position. At the beginning of the second surgery, at which a vertical transposition of the horizontal muscles of the left eye after the technique of Knapp was planned, it was noticed during anesthesia induction that, as the child passed through stage II of the general anesthesia, both eyes briefly elevated, the DEP affected left eye (post 6 mm IR recession) more than the right. A photograph was taken to record this phenomenon.

Discussion and conclusion: As of this report, there are now at least 4 distinct circumstances under which distinct elevation of eyes diagnosed with DEP have been observed. These 4 include Bell's phenomenon, Dissociated Vertical Deviation of the affected DEP eye, normal upgaze saccades recorded moving from the downgaze position into the primary position, and now elevation during Stage II of a general anesthetic induction. Further, there is no abnormal head posture (head tilt) in patients with DEP, no Bielschowsky phenomenon. All of these pieces of clinical evidence confirm that DEP is not a palsy at all. Instead, they strongly suggest that it is absence of function of a unilateral center for supraduction.

Purpose: To investigate the final surgical outcome in horizontal strabismus correction, measured in primary position of gaze, in two situations: 1. When surgery was performed only on the horizontal rectus muscles; and 2. When inferior or superior oblique muscle weakening procedures were simultaneously performed.

Methods: Two hundred thirty cases were analyzed retrospectively: 172 esotropias (110 without oblique overaction; 23 with inferior oblique overaction; and 39 with superior oblique overaction), and 58 exotropias (25 without oblique overaction; 19 with inferior oblique overaction; and 14 with superior oblique overaction). Initial and final deviations, as well as the amount of correction achieved, was compared in six groups.

Results: No differences in outcomes and final results were found between any of the major or minor groups of patients.

Conclusions: Oblique muscle weakening, in combination with horizontal muscle strabismus surgery did not affect the final results of the horizonal surgery in primary position. This study did suggest that there might not be a need for increasing or decreasing amounts of surgery on the horizontal rectus muscles to correct eso- or exotropia when oblique weakening procedures are included.

Introduction and purpose: To describe a new operation to treat unilateral chronic sixth nerve paresis based on Sherrington's innervational law. A recession of the medial rectus (MR) in the good eye, yoke to the paretic lateral rectus (LR), will have the reciprocal innervational effect of relaxing the contracture of the contralateral MR and by doing so will enhance the effect of a weakening procedure performed on this muscle. The goal of this study was to eliminate diplopia in primary position by improving the function of the paretic LR and reducing the contracture of its antagonist MR.

Methods: The records of 14 consecutive patients with unilateral chronic sixth nerve paresis so treated were reviewed. Nine had bilateral medial rectus muscle retroplacement and postop' adjustable sutures. A non-adjustable resection of the paretic lateral rectus muscle was added to the other five. Average time from onset to surgery was 60 months (minimum 9 months). Average post-surgical followup was 22 months.

Results: The function of the paretic LR and the contracture of the ipsilateral MR were improved in all 14 cases. Patients with bilateral medial rectus recessions and postop' adjustable sutures had an average correction of 32 prism diopters in primary position. Patients with the added resection of the paretic LR had an average correction in primary position of 46 prism diopters. Two of the 14 patients failed our goals; one had residual diplopia in primary position and the other one had diplopia within 30 degrees on gaze to one side; for an 86% success rate.

Conclusions: The 86% success rate in this study (ultimately we also achieved a 100% satisfaction rate) indicates that innervational surgery in the form of a recession of the MR in the good eye added to that of the MR in the involved eye in patients with unilateral chronic sixth nerve paresis is a safe and effective surgical procedure.