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Jeong-min Hwang - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Slow-Releasing All-Trans-Retinoic Acid in Bioabsorbable Polymer on Delayed Adjustable Strabismus Surgery in a Rabbit Model
    American journal of ophthalmology, 2009
    Co-Authors: Min Joung Lee, Su-eon Jin, Chong-kook Kim, Ho-kyung Choung, Hwa Jung Kim, Jeong-min Hwang
    Abstract:

    Purpose To determine the usefulness of slow-releasing all- trans -retinoic acid (ATRA) in polytetrafluoroethylene (PTFE)/polylactide-co-glycolide (PLGA) for delayed adjustable strabismus surgery. Design Animal study. Methods A prospective, masked-observer, controlled study was performed in 25 rabbits. Fifty rabbit eyes were divided randomly into three groups. After a recession of the Superior Rectus Muscle, a PTFE/PLGA laminate containing ATRA, PTFE alone, or balanced salt solution was applied beneath and over the Superior Rectus Muscle in the PTFE/PLGA/all- trans -retinoic acid group (ATRA group), the polytetrafluoroethylene group (PTFE group), and the control group, respectively. Delayed adjustment was performed once on each Superior Rectus Muscle at 3 or 5 weeks after surgery by a masked observer. Results In the control group, adjustment was possible in 2 of 5 eyes at 3 weeks after surgery and impossible in any eye at 5 weeks after surgery. In the PTFE and ATRA groups, adjustment was possible in all 10 eyes at 3 and 5 weeks after surgery. On comparing adjustability, a significant difference was observed between the PTFE group and the control group or between the ATRA group and the control group 5 weeks after surgery ( P = .0003 and P = .0003, respectively). A significant difference was observed between the ATRA group and the control group in terms of adhesion between Superior Rectus Muscles and sclerae at 5 weeks after surgery ( P = .006). Conclusions Slow-releasing ATRA in PTFE/PLGA was found to reduce adhesion and to allow delayed adjustment in most eyes for up to 5 weeks after surgery.

  • Imaging of the Superior Rectus in Superior Rectus Overaction after Retrobulbar Anesthesia
    Ophthalmology, 2006
    Co-Authors: Jae Hyoung Kim, Jeong-min Hwang
    Abstract:

    Objective Vertical diplopia after cataract surgery caused by an overaction of an extraocular Muscle is more common when the Superior Rectus Muscle is involved, whereas contracture is more common when the inferior Rectus Muscle is involved. However, no documented imaging has been presented. The aim of this report was to study the Superior Rectus in such a patient with magnetic resonance imaging (MRI). Design Observational case report. Methods Ophthalmologic examination and thin-sectioned MRI across the Superior Rectus Muscle were performed in a patient with Superior Rectus overaction after cataract surgery. Main Outcome Measures Ocular alignment, ocular movement, and the Superior Rectus Muscle on MRI. Results Magnetic resonance imaging disclosed focal thickening of the Superior Rectus Muscle near the orbital apex in a patient who showed Superior Rectus overaction after retrobulbar anesthesia for cataract extraction. Conclusions The focal thickening of the Superior Rectus Muscle in this patient is consistent with the theory that segmental contracture leads to overactive Muscles after retrobulbar anesthesia.

  • Combined effect of polytetrafluoroethylene and 5-fluorouracil on delayed adjustable strabismus surgery.
    Journal of pediatric ophthalmology and strabismus, 2000
    Co-Authors: Jeong-min Hwang, Bong Leen Chang
    Abstract:

    PURPOSE To determine a more reliable method for performing delayed suture adjustment to prevent the formation of postoperative adhesions and delay the time of adjustment. METHODS Thirty-two rabbit eyes were divided into three groups. After recession of the Superior Rectus Muscle, 5-fluorouracil (5-FU) was administered beneath and over the Superior Rectus Muscle in group 5-FU (12 eyes); polytetrafluoroethylene (PTFE) and 5-FU were administered in group P-f (10 eyes); and PTFE, 5-FU, and Viscoat (chondroitin sulfate, sodium hyaluronate, Alcon Laboratories Inc, Fort Worth, Tex) were administered in group P-fv (10 eyes). Delayed adjustment was performed once on each Superior Rectus Muscle at 1, 2, and 3 weeks postoperatively in group 5-FU and at 2 and 4 weeks postoperatively in groups P-f and P-fv. The length and force for the adjustment and the degree of adhesions were recorded. RESULTS The use of fluorouracil allowed adjustment to be delayed up to 1 week after surgery in three of four eyes. The combined use of PTFE and 5-FU or addition of Viscoat allowed adjustment to be delayed for up to 4 weeks after surgery in four of five eyes. CONCLUSION The combined use of PTFE, 5-FU and Viscoat is useful for delaying suture adjustment in rabbit eyes.

R A Harrad - One of the best experts on this subject based on the ideXlab platform.

  • Unilateral congenital ptosis with ipsilateral Superior Rectus Muscle overaction.
    American journal of ophthalmology, 1996
    Co-Authors: David H. W. Steel, R A Harrad
    Abstract:

    Purpose Congenital ptosis may be accompanied by weakness of the ipsilateral Superior Rectus Muscle. We report the finding of a hypertropia of the ipsilateral eye in patients with isolated unilateral congenital ptosis that became manifest only in upgaze. Methods Seventy consecutive patients with congenital ptosis were recalled and 58 reexamined. Examination included assessment of visual acuities, palpebral apertures, levator Muscle function, and an orthoptic examination. Particular attention was paid to the assessment of upgaze. Results Thirty-eight patients had an isolated unilateral congenital ptosis. Four patients had bilateral ptosis, six had upgaze deficits, and ten others had a variety of other syndromes associated with ptosis. Seventeen of the 38 patients with isolated unilateral congenital ptosis were found to have an ipsilateral hypertropia on upgaze. The size of the vertical deviation varied from 5 to 30 prism diopters and, in the more severe cases, produced a cosmetic problem that became more noticeable after successful ptosis surgery. In one of these patients, a Superior Rectus Muscle posterior fixation suture was effective in reducing the hypertropia. Conclusion Of a number of possible causes for the ipsilateral hypertropia in upgaze in patients with unilateral congenital ptosis that we observed, either a misdirection syndrome within the Superior division of the oculomotor nerve or an exaggerated Bell's reflex is the most likely.

Scott R. Lambert - One of the best experts on this subject based on the ideXlab platform.

  • Superior Rectus Muscle Overaction After Cataract Extraction
    American journal of ophthalmology, 1992
    Co-Authors: Michael R. Grimmett, Scott R. Lambert
    Abstract:

    Four patients with an ipsilateral hypertropia after cataract extraction consistent with Superior Rectus Muscle overaction were identified between March 1990 and April 1992. Operative trauma was the most likely causative factor, as other likely conditions were excluded. The proposed pathogenesis for all cases is similar to that of botulinum type-A toxin therapy: a transient postoperative weakness of the ipsilateral inferior Rectus Muscle leads to a contracture or strengthening of the ipsilateral antagonist (the Superior Rectus Muscle). Possible mechanisms of injury that would result in a transient inferior Rectus Muscle palsy would include anesthetic myotoxicity or direct trauma to the Muscle and related structures from the retrobulbar injection (or subconjunctival injection). Surgical intervention consisting of an ipsilateral Superior Rectus Muscle recession and posterior fixation sutures (when the vertical incomitance was large) yielded excellent results in restoring single binocular vision. Possible preventive measures would include using a minimal volume of anesthetic along with careful needle placement.

María Cristina Ugrin - One of the best experts on this subject based on the ideXlab platform.

  • frequency of the Superior Rectus Muscle overaction contracture syndrome in unilateral fourth nerve palsy
    Journal of Aapos, 2009
    Co-Authors: Andrea Molinari, María Cristina Ugrin
    Abstract:

    Introduction Superior oblique palsy is accompanied in most cases by overaction of the Muscle's ipsilateral antagonist, the inferior oblique Muscle. Overaction and contracture of the ipsilateral Superior Rectus Muscle in patients with unilateral fourth (trochlear) nerve palsy is seldom discussed in the literature. The purpose of this study is to evaluate the frequency of Superior Rectus Muscle overaction/contracture syndrome in patients with unilateral trochlear nerve palsy. Subjects and Methods The records of 198 patients with unilateral trochlear nerve palsy examined by the authors between July 1987 and July 2008 were reviewed retrospectively. All patients underwent complete eye examination with measurement of the deviation in the 9 positions of gaze and with the head tilted to both sides in all cooperative patients. Selection criteria for Superior Rectus Muscle overaction/contracture syndrome in these patients were as follows: vertical deviation of 15Δ or larger in primary position, equal or larger hypertropia with the ipsilateral forced tilt test than with the eyes looking straight ahead, more than 5Δ hypertropia of the affected eye in horizontal gaze to the same side, hypertropia in all upgazes, and overaction of the contralateral Superior oblique Muscle. Results Of 198 patients, 33 (16.6%) met the selection criteria for Superior Rectus Muscle overaction/contracture syndrome. Conclusions Superior Rectus Muscle overaction/contracture syndrome frequently occurs in unilateral Superior oblique palsy.

  • Frequency of the Superior Rectus Muscle overaction/contracture syndrome in unilateral fourth nerve palsy
    Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus, 2009
    Co-Authors: Andrea Molinari, María Cristina Ugrin
    Abstract:

    Introduction Superior oblique palsy is accompanied in most cases by overaction of the Muscle's ipsilateral antagonist, the inferior oblique Muscle. Overaction and contracture of the ipsilateral Superior Rectus Muscle in patients with unilateral fourth (trochlear) nerve palsy is seldom discussed in the literature. The purpose of this study is to evaluate the frequency of Superior Rectus Muscle overaction/contracture syndrome in patients with unilateral trochlear nerve palsy. Subjects and Methods The records of 198 patients with unilateral trochlear nerve palsy examined by the authors between July 1987 and July 2008 were reviewed retrospectively. All patients underwent complete eye examination with measurement of the deviation in the 9 positions of gaze and with the head tilted to both sides in all cooperative patients. Selection criteria for Superior Rectus Muscle overaction/contracture syndrome in these patients were as follows: vertical deviation of 15Δ or larger in primary position, equal or larger hypertropia with the ipsilateral forced tilt test than with the eyes looking straight ahead, more than 5Δ hypertropia of the affected eye in horizontal gaze to the same side, hypertropia in all upgazes, and overaction of the contralateral Superior oblique Muscle. Results Of 198 patients, 33 (16.6%) met the selection criteria for Superior Rectus Muscle overaction/contracture syndrome. Conclusions Superior Rectus Muscle overaction/contracture syndrome frequently occurs in unilateral Superior oblique palsy.

Fumio Shiraga - One of the best experts on this subject based on the ideXlab platform.

  • Large Bielschowsky head-tilt phenomenon and inconspicuous vertical deviation in the diagnostic positions in congenital Superior oblique palsy.
    American journal of ophthalmology, 2000
    Co-Authors: Hiroshi Ohtsuki, Satoshi Hasebe, Reika Kono, Takashi Yamane, Hirotake Fujiwara, Fumio Shiraga
    Abstract:

    Abstract PURPOSE: To report a case of congenital Superior oblique palsy with an unusually large Bielschowsky head-tilt phenomenon (BHP) and disproportional inconspicuous vertical deviation. METHODS: Case report. RESULTS: An 18-year-old woman presented with slight compensatory head tilting and a Bielschowsky head-tilt phenomenon of 50 Δ on left tilting. Magnetic resonance imaging revealed atrophy of the left Superior oblique Muscle. A Hess screen test showed a slight underaction of the left Superior oblique Muscle, but neither an obvious overaction of the ipsilateral inferior oblique Muscle nor inhibitory palsy of the contralateral Superior Rectus Muscle was found. With a 3-mm recession of the ipsilateral Superior Rectus Muscle, Bielschowsky head-tilt phenomenon decreased to 25 Δ. CONCLUSION: A large Bielschowsky head-tilt phenomenon was possibly caused by an increased gain of the otolith-ocular reflex affecting the vertical Rectus Muscle.