Modified inferior oblique anterior transposition for dissociated vertical deviation combined with superior oblique palsy:A case report

BACKGROUND Inferior oblique anterior transposition(IOAT)has emerged as an effective surgery in the management of dissociated vertical deviation(DVD)combined with superior oblique palsy(SOP).Traditional IOAT usually provides satisfactory primary position alignment and simultaneously restricts the superior floating phenomenon.However,it also increases the risk of the anti-elevation syndrome and narrowing of the palpebral fissure in straight-ahead gaze,especially after the unilateral operation.CASE SUMMARY We report the outcomes of the modified unilateral IOAT in two patients with unilateral DVD combined with SOP.The anterior-nasal fibers of the inferior oblique muscle were attached at 9 mm posterior to the corneal limbus along the temporal board of the inferior rectus muscle,the other fibers were attached a further 5 mm temporal to the anterior-nasal fibers.Postoperatively,both hypertropia and floating were improved,and no obvious complications occurred.CONCLUSION In these cases,the modified unilateral IOAT was an effective and safe surgical method for treating DVD with SOP.

Vertical deviation and A pattern of type Ⅲ Duane retraction syndrome

Background Researches in ocular electromyography （EMG） and Magnetic resonance imaging （MRI） of patients with Duane retraction syndrome （DRS） suggest that there may be additional abnormalities such as paradoxical innervation between horizontal rectus muscles and vertical rectus muscles, hypoplasia of vertical rectus muscle and that oblique muscles may also contribute to the heterogeneity of the clinical manifestation of DRS. This paper reports the results of superior rectus recession for vertical deviation and A pattern in DRS Type III and discusses the pathogenesis of the disease. Methods Superior and lateral rectus recession were performed in 5 cases of Huber type III DRS to treat vertical deviation and A pattern strabismus. Before operation, MRI of the brain, brainstem, cavernous sinus, and orbits were performed. Results All subjects had unilateral limitation of both abduction and adduction, with palpebral fissure narrowing and globe retraction in adduction. Three cases had A pattern of strabismus, three cases had hypertropia. The abducens nerves （CN6） were either absent or hypoplasitic in the brainstem in all patients. Two eyes had larger oculomotor foramen. Two eyes had hypoplasia of the superior rectus and the inferior rectus. There was presumably a branch of the third cranial nerve （CN3） innervating the lateral rectus （LR） in one eye. While in another eye, two branches of CN3 sent into medial rectus were revealed. After surgery, vertical deviation in the primary position was reduced in all patients and A pattern was eliminated in 3 patients. One patient developed 10A consecutive esotropia postoperatively. Conclusion The results suggest that structural abnormalities of vertical muscle and abnormal orbital innervation may be related to vertical deviation and the presence of A pattern in DRS type Ⅲ. Recession of the superior rectus muscle seems to be a safe and effective treatment for vertical deviation and A pattern strabismus in DRS Type Ⅲ.

Vertical deformation of the fault-crossing network around Baotou,observed by GPS

GPS data and precise leveling data of seismic network profiles across the fault in Baotou in 2006, 2009 and 2011 were processed and analyzed to test the feasibility of using GPS technology for fault-crossing vertical deformation monitoring. The results showed that high precision cross-fauh vertical deformation measurements can be obtained using appropriate GPS data processing strategies.

Surgical outcomes for unilateral superior oblique palsy in Chinese population: a retrospective study

AIM: To evaluate the outcome after surgery for unilateral superior oblique(SO) palsy in Chinese.METHODS: The medical records of 39 patients that underwent surgery for unilateral SO palsy between January 2003 and December 2012 at Caritas Medical Centre, Hong Kong, were retrospectively reviewed. All surgeries were performed by a single surgeon. Pre-operative assessments for vertical deviation, cyclo-deviation, and Knapp’s classification were obtained to determine the nature and degree of surgical correction.Vertical deviation was measured at 1wk; 1, 6mo and on last follow-up day post-operatively. Cyclo-deviation was measured on last follow-up day post-operatively.RESULTS: During the 10 y period, 39 subjects were recruited. The most common etiology was congenital(94.9%). Knapp’s Type III(66.7%) and Type I(12.8%)classifications were the most common subtypes. To treat SO palsy, the most common surgical procedures were:isolated inferior oblique(IO) anteriorization(41.0%),isolated IO myectomy(10.3%), and isolated IO recession(10.3%). At 3.5 ±2.1y post-operatively, the vertical deviation was significantly reduced(15.1 ±6.2 PD versus0.5±1.4 PD, P 【0.0001) without significant improvement in cyclo-deviation(P =0.5). Initial vertical deviation was correlated with cyclo-torsion(r =0.4, P =0.007). Those with over-correction had greater initial vertical deviation(19.4±7.2 PD versus 13.2±4.3 PD, P =0.003). After a single operation, 84.6% of subjects achieved a vertical deviation within ±3 PD.· CONCLUSION: The majority of subjects achieved corrected vertical deviation after a single surgery although there was no improvement in cyclo-deviation.Those with over-correction of primary position deviation had greater preoperative vertical deviation and it may be related to simultaneous multiple muscle surgery.