Rescue of exotropia subsequent to pulled-in-two syndrome of the medial rectus muscle occurring during surgery for high myopic strabismus fixus: A case report

Rationale: Pulled-in-two syndrome is one of the significant complications of strabismus surgery. This study aimed to report a case of pulled-in-two syndrome of the contractured medial rectus muscle (MR) that occurred during strabismus surgery for strabismus fixus due to high myopia, and to describe a rescue of this complication. Patient concerns: A woman in her 60s presented to our Ophthalmology Department with the main complaint of unilateral high myopia and severe myopic strabismus fixus. Esotropia exceeded 45° and hypotropia exceeded 15° in her right eye in the Hirschberg test. Right eye duction was markedly limited in every gaze direction. Orbital magnetic resonance images showed rupture of the superior rectus to lateral rectus band ligament and lengthening of the distance between the SR and LR muscles in the right eye. Diagnosis: Due to the patient's ophthalmic examination and imaging results, she was diagnosed with high myopic strabismus fixus. Interventions: We performed MR recession and Yokoyama surgery to correct right eye hypoesotropia. In the MR recession procedure, pulled-in-two syndrome (MR muscle tear) occurred. Thus, no additional procedure was performed on the MR. After the surgery, she presented 45 prism diopter exotropia and 18 prism diopter residual right hypotropia in a Krimsky test. We performed a second surgery, combining MR muscle advancement and inferior rectus (IR) muscle recession, 3 months after the first surgery. Outcomes: One and a half years after the second surgery, she presented exotropia of 14 prism diopters without hypotropia in the Krimsky test and was satisfied with her ocular position and improved motility. Lessons: We experienced pulled-in-two syndrome in a case with severe myopic strabismus fixus and achieved a good outcome by performing additional surgery 3 months later, in which the lost MR muscle was advanced. This case underscores that, if the lost muscle cannot be found during surgery, one should maintain composure and perform a reoperation a few months after the initial surgery, if necessary. This case report can aid in making rescue treatment decisions when pulled-in-two syndrome occurs

Relationship between Soil Chemical and Physical Properties and Vegetation in the Latest Decade of Alpine Grasslands of Southern Qinghai, China

The Tibetan Plateau is one of the most important ecosystems in the world (Yang et al. 2009), particularly because of the global importance of its climate (Tian et al. 2008; Wang et al. 2008). Grassland ecosystems on the plateau are sensitive to global change, because the plateau is located in marginal land areas where the growth and distribution of plants depend heavily on local climatic conditions (Zhang et al. 1996). The alpine grassland of Qinghai Province in China has been traditionally used for extensive grazing by sheep and yak (Bos grunniens), but is now degraded from overgrazing. This study investigated the relationship between soil chemical and physical properties and vegetation of alpine grasslands of southern Qinghai, China

ELKS/Voltage-Dependent Ca²⁺ Channel-beta Subunit Module Regulates Polarized Ca²⁺ Influx in Pancreatic beta Cells

Pancreatic β cells secrete insulin by Ca²⁺-triggered exocytosis. However, there is no apparent secretory site similar to the neuronal active zones, and the cellular and molecular localization mechanism underlying polarized exocytosis remains elusive. Here, we report that ELKS, a vertebrate active zone protein, is used in β cells to regulate Ca²⁺ influx for insulin secretion. β cell-specific ELKS-knockout (KO) mice showed impaired glucose-stimulated first-phase insulin secretion and reduced L-type voltage-dependent Ca²⁺ channel (VDCC) current density. In situ Ca²⁺ imaging of β cells within islets expressing a membrane-bound G-CaMP8b Ca²⁺ sensor demonstrated initial local Ca²⁺ signals at the ELKS-localized vascular side of the β cell plasma membrane, which were markedly decreased in ELKS-KO β cells. Mechanistically, ELKS directly interacted with the VDCC-β subunit via the GK domain. These findings suggest that ELKS and VDCCs form a potent insulin secretion complex at the vascular side of the β cell plasma membrane for polarized Ca²⁺ influx and first-phase insulin secretion from pancreatic islets