Advancement of medial rectus muscle to the original insertion for consecutive exotropia

Twenty-four patients who underwent surgery to correct consecutive exotropia that developed iatrogenically after surgical overcorrection were studied retrospectively. All patients underwent single or bilateral advancement of the medial rectus muscle to the original muscle insertion. The mean preoperative exodeviation was 26.7 prism diopters at distance and 35.2 delta at near. Postoperatively, in cases receiving advancement of a single medial rectus, the mean amount of correction was 23.2 delta at distance and 29.6 delta at near. In cases receiving bilateral medial rectus advancement, the mean amount of postoperative correction was 26.3 delta at distance and 39.8 delta at near. Adduction deficiency was normalized in five patients (71%), while convergence insufficiency was improved in only nine patients (45%) after surgery. Twelve (50%) patients had binocular single vision at distance on a normal or abnormal basis as determined by the Bagolini lens test.

Critical period for restoration of normal stereoacuity in acute-onset comitant esotropia

We conducted a retrospective study of 25 patients with acute-onset comitant esotropia to evaluate whether the timing of the start of treatment is a critical factor in the development of normal stereopsis. The mean age at onset was 12 years 4 months, and mean age at the start of treatment was 17 years 9 months. Bifixation was defined as a stereoacuity threshold score that was numerically lower than 60 seconds of arc on stereotesting. An operation was performed on the nonfixating eye for the prism-adapted angle. At the final examination, bifixation was observed in four patients (16%) with the Randot test and in 15 patients (60%) with the Titmus test. No relationship was found between the time of the start of treatment and the postoperative development of stereopsis, nor was there a significant (P > .10) difference between the two groups with early and delayed start of treatment in the proportion of patients with bifixation.

Extraocular muscle surgery in a rabbit model: site of reattachment following hang-back and conventional recession

To determine the precise site of reattachment of recessed muscles, 4-mm conventional and hang-back recessions of the inferior rectus muscle were performed in 18 albino rabbits. Six weeks later, the distance from the anterior border of the reattached muscle to the insertion was measured both grossly and microscopically. In all cases the operated muscles had advanced minimally from the site of surgical placement. Gross observation showed that the mean forward creep was significantly greater for those rabbits which underwent hang-back recession (1.81 +/- 0.67 mm) than for those that were submitted to the conventional technique (0.83 +/- 0.38 mm). Measurements done on histological sections revealed that the mean distance of the anterior border of the muscle fiber from the reference suture was larger for conventional recession (2.73 +/- 0.75 mm) than for hang-back recession (1.91 +/- 0.72 mm).

Clinical studies of ocular motility disturbances: Part 2. Risk factors for ischemic ocular motor nerve palsy [corrected]

A case-control study of 46 Japanese patients who were diagnosed by exclusion as having ischemic ocular motor nerve palsy and who exhibited spontaneous recovery within 4 months was done to evaluate the risk factors involved. We also evaluated the association between the number of risk factors and the spontaneous recovery or recurrence periods. Ischemic ocular motor nerve palsy is closely related to diabetes mellitus and coronary artery disease. Patients tended to be obese; many had two or more risk factors. Aging, in combination with two or more risk factors, seems to increase the likelihood of developing this disease. Diabetes mellitus is a particularly significant risk factor for this type of palsy, especially in combination with hypertension.

Brain Pericytes Acquire Stemness via the Nrf2-Dependent Antioxidant System

Pericytes (PCs) are a mural support cell population elongated at intervals along the walls of capillaries. Recent studies reported that PCs are multipotent cells that are activated in response to tissue injury and contribute to the regenerative process. Using a C.B-17 mouse model of ischemic stroke, it has been proposed that normal brain pericytes (nPCs) are converted to ischemic pericytes (iPCs), some of which function as multipotent stem cells. Furthermore, oxygen-glucose deprivation (OGD) promoted mesenchymal-epithelial transition in nPCs; however, nestin was not induced under OGD conditions. Therefore, further studies are needed to elucidate the PC reprogramming phenomenon. We herein isolated nPCs from the cortex of C.B-17 mice, and compared the traits of iPCs and nPCs. The results obtained showed that nPCs and iPCs shared common pericytic markers. Furthermore, intercellular levels of reactive oxygen species and the nuclear accumulation of nuclear factor erythroid-2-related factor 2 (Nrf2), a key player in antioxidant defenses, were higher in iPCs than in nPCs. OGD/reoxygenation and a treatment with tBHQ, an Nrf2 inducer, increased nestin levels in nPCs. Moreover, epithelial marker levels, including nestin, Sox2, and CDH1 (E-cadherin) mRNAs, were elevated in Nrf2-overexpressing PCs, which formed neurosphere-like cell clusters that differentiated into Tuj1-positive neurons. The present results demonstrate that oxidative stress and Nrf2 are required for the generation of stem cells after stroke and will contribute to the development of novel therapeutic strategies for ischemic stroke.

Intraoperative suspension-recession technique for treatment of vertical strabismus in thyroid myopathy

Ten patients underwent extraocular muscle surgery with an intraoperative suspension-recession technique for diplopia induced by vertical strabismus in thyroid myopathy. The average ratio of the reduction of vertical deviation to the amount of surgery was 1.8 degrees/mm (range, 1.0 degrees/mm-2.8 degrees/mm). Eight (80%) patients had single binocular vision restored in the primary position without prism or compensatory torticollis after surgery. One patient who showed evidence of abnormal thyroid function at surgery developed an overcorrection postoperatively.

[Motor adaptation in the Bielschowsky head-tilt test in cases of superior oblique palsy]

To elucidate a motor adaptation phenomenon in the Bielschowsky head-tilt test in cases of superior oblique palsy, a gain of the otolith-ocular reflex was studied. The amplitude of ocular counter-rolling (OCR) of the non-paretic eye was measured with a photographic method, using limbal conjunctival marks as landmarks which were marked with indigo carmine. The average preoperative OCR of the non-paretic eye was 10.49 degrees at 30 degrees of head tilt to both sides, but after corrective surgery in the paretic eye the OCR of the non-paretic eye decreased to 8.43 degrees. To clarify the relation between OCR, duration of palsy and vertical deviation of the Bielschowsky head-tilt test (BHP), which was the difference of vertical deviation measured with the head tilted to the left and right shoulders at an angle of 30 degrees, the BHP/OCR ratio was calculated. We found no relation between BHP and OCR, but the BHP/OCR ratio increased proportionally in cases of long-standing palsy, From these results an increased BHP/OCR ratio could be an adaptive phenomenon caused by secondary innervational changes or muscle contracture to minimizing the contralateral head tilt to maintain binocular single vision.

Clinical studies of ocular motility disturbances. Part 1. Ocular motility disturbances: causes and incidence

Between January 1985 and December 1994, 500 cases of ocular motility disturbances were encountered in our department; we analyzed these statistically. There were 48 cases of supranuclear palsy (10%), 281 of ocular motor nerve palsies (56%), 19 with myasthenia gravis (4%), 29 with myogenic palsy (6%), 57 with abnormal innervation (11%), and 63 instances of mechanical disturbances (13%). There were more men than women in all groups except myasthenia gravis. Eighty-four ocular motor nerve palsy and 15 blowout fracture patients recovered spontaneously. Spontaneous recovery occurred within 6 months in 80 (93%) patients with ocular motor nerve palsy. The abnormality detection rate, using diagnostic imaging, was high for supranuclear and myogenic palsy and the mechanical disturbance groups, but very low for the ocular motor nerve palsy groups. In 3 supranuclear palsy patients, small infarctions of the brainstem were discovered by magnetic resonance imaging (MRI) but were not found with computed tomography (CT). MRI thus proved useful in detecting abnormalities of brainstem lesions.