In this study, we explored the neural mechanism underlying impaired stereopsis and possible functional plasticity after strabismus surgery. We enrolled 18 stereo-deficient patients with intermittent exotropia before and after surgery, along with 18 healthy controls. Functional magnetic resonance imaging data were collected when participants viewed three-dimensional stimuli. Compared with controls, preoperative patients showed hypoactivation in higher-level dorsal (visual and parietal) areas and ventral visual areas. Pre- and postoperative activation did not significantly differ in patients overall; patients with improved stereopsis showed stronger postoperative activation than preoperative activation in the right V3A and left intraparietal sulcus. Worse stereopsis and fusional control were correlated with preoperative hypoactivation, suggesting that cortical deficits along the two streams might reflect impaired stereopsis in intermittent exotropia. The correlation between improved stereopsis and activation in the right V3A after surgery indicates that functional plasticity may underlie the improvement of stereopsis. Thus, additional postoperative strategies are needed to promote functional plasticity and enhance the recovery of stereopsis.
Humans ; Exotropia/surgery* ; Depth Perception/physiology* ; Strabismus/surgery* ; Oculomotor Muscles/surgery*

PURPOSE: To evaluate differences in self-identity in patients diagnosed with strabismus, patients who underwent strabismus surgery, and healthy control individuals. METHODS: Self-identity testing was done during a military service physical examination. There were three subject groups: subjects with strabismus (group 1), subjects who had undergone corrective strabismus surgery (group 2), and subjects free of strabismus (group 3). The self-identity test was comprised of six sub-sections (subjectivity, self-acceptance, future confidence, goal orientation, initiative, and familiarity). Statistical significance of the sub-sections was compared across the three groups. Correlations in age at the time of surgery and across the six sub-sections were investigated in group 2. RESULTS: A total of 351 subjects were enrolled in the study; 96 subjects were in group 1, 108 subjects were in group 2, and 147 subjects were in group 3. Significant differences were evident in subjectivity, self-acceptance, initiative and familiarity between groups 1 and 3. No significant differences were found between groups 2 and 3. In group 2, statistical significance was evident between age at surgery and initiative and familiarity (r = −0.333, p < 0.001; r = −0.433, p < 0.001, respectively). CONCLUSIONS: Self-identity is greater in non-strabismus subjects than strabismus subjects. Correction of strabismus may increase self-identity levels.
Adolescent ; Adult ; Eye Movements/*physiology ; *Facial Expression ; Female ; Humans ; Male ; Oculomotor Muscles/*physiopathology/surgery ; Ophthalmologic Surgical Procedures ; Retrospective Studies ; *Self Concept ; Strabismus/physiopathology/*psychology/surgery

PURPOSE: To investigate the long-term clinical course of intermittent exotropia after surgical treatment to determine whether and when postoperative exo-drift stabilizes, and the required postsurgery follow-up duration in cases of intermittent exotropia. METHODS: We retrospectively reviewed the medical records of patients diagnosed with intermittent exotropia who underwent surgical treatment between January 1992 and January 2006 at Yeungnam University Hospital and postoperatively performed regular follow-up examinations for up to 7 years. We also analyzed the difference in exo-drift stabilization, according to surgical procedure. RESULTS: A total of 101 patients were enrolled in the study. Thirty-one patients underwent lateral rectus recession and medial rectus resection (R&R) and 70 patients underwent bilateral lateral rectus recession (BLR). The postoperative angles of deviation increased significantly during the initial 36 months, but no subsequent significant changes were observed for up to 84 months. Follow-ups for 7 years revealed that more than 50% of the total amount of exo-drift was observed within the first postoperative year. In addition, the angles of deviation at 1 year correlated with those at 7 years postoperatively (Pearson correlation coefficient r = 0.517, p < 0.001). No significant exo-drift was observed after 36 months in patients who underwent BLR, whereas after 18 months in patients who underwent R&R. CONCLUSIONS: The minimum postoperative follow-up required after surgical treatment to ensure stable results is 36 months. In particular, careful follow-up is necessary during the first postoperative year to detect rapid exo-drift. Patients who underwent BLR required a longer follow-up than those who underwent R&R to ensure stable postoperative alignment.
Child ; Child, Preschool ; Exotropia/*physiopathology/surgery ; Female ; Follow-Up Studies ; Humans ; Male ; Oculomotor Muscles/*physiopathology/surgery ; *Ophthalmologic Surgical Procedures ; Postoperative Complications/*physiopathology ; Retrospective Studies ; Vision, Binocular/physiology ; Visual Acuity/physiology

PURPOSE: To compare postoperative exodrift of the first unilateral lateral rectus (ULR) muscle recession with the exodrift of the second contralateral ULR muscle recession in patients with recurrent small-angle exotropia (XT). METHODS: We evaluated the results of a second ULR muscle recession in 19 patients with recurrent XT with deviation angles under 25 prism diopter (PD), following a first procedure of ULR muscle recession for small-angle XT. Recession of the lateral rectus muscle ranged from 8 to 9 mm. The postoperative motor alignment and degree of exodrift were investigated after the first ULR muscle recession and the second ULR muscle recession in the same patients. RESULTS: Observed differences in postoperative ocular alignment between the first ULR muscle recession and the second ULR muscle recession were statistically significant at follow-up periods of six months (7.84 +/- 4.43 vs. 3.89 +/- 3.47 PD), one year (9.58 +/- 4.97 vs. 5.21 +/- 4.94 PD), and at a final follow-up (21.11 +/- 2.98 vs. 7.52 +/- 4.06 PD) after surgery (p = 0.006, 0.013, and 0.000). Postoperative exodrift was statistically different between the first and second ULR muscle recessions at three to six months (2.89 +/-3.75 vs. 0.63 +/- 3.45 PD) and one year to final follow-up (11.52 +/- 5.50 vs. 2.32 +/- 3.53 PD) (p = 0.034 and 0.000). All of the first ULR muscle recession patients showed XT with deviation angles of more than 15 PD at the final follow-up. Regardless, the surgical success rate (<8 PD) after the second ULR recession was 63.16% (12 patients) among the total amount of patients with recurrent XT. CONCLUSIONS: This study shows that changes in exodrift after a second ULR muscle recession are less than changes after the first URL muscle recession among patients with recurrent XT. A second ULR muscle recession may be a useful surgery for small-angle XT patients with deviation angles of 25 PD or less after a first ULR muscle recession.
Child ; Child, Preschool ; *Exotropia/etiology/physiopathology/surgery ; Female ; Follow-Up Studies ; Humans ; Male ; Oculomotor Muscles/physiopathology/*surgery ; *Ophthalmologic Surgical Procedures ; *Postoperative Complications ; Recurrence ; Retrospective Studies ; Vision, Binocular/physiology

No abstract available.
Child ; Eye Movements/*physiology ; Humans ; Male ; Oculomotor Muscles/physiopathology/*surgery ; Ophthalmologic Surgical Procedures/*methods ; Strabismus/physiopathology/*surgery ; Syndrome

PURPOSE: The purpose of this study is to compare the magnitude and axis of astigmatism induced by a combined inferior oblique (IO) anterior transposition procedure with lateral rectus (LR) recession versus LR recession alone. METHODS: Forty-six patients were retrospectively analyzed. The subjects were divided into two groups: those having concurrent inferior oblique muscle overaction (IOOA) and intermittent exotropia (group 1, 20 patients) and those having only intermittent exotropia as a control (group 2, 26 patients). Group 1 underwent combined anterior transposition of IO with LR recession and group 2 underwent LR recession alone. Induced astigmatism was defined as the difference between preoperative and postoperative astigmatism using double-angle vector analysis. Cylinder power, axis of induced astigmatism, and spherical equivalent were analyzed at 1 week, 1 month, and 3 months after surgery. RESULTS: Larger changes in the axis of induced astigmatism were observed in group 1, with 4.5° incyclotorsion, than in group 2 at 1 week after surgery (axis, 84.5° vs. 91°; p < 0.001). However, there was no statistically significant inter-group difference thereafter. Relaxation and rapid regression in the incyclotorsion of induced astigmatism were observed over-time. Spherical equivalent significantly decreased postoperatively at 1 month in both groups, indicating a myopic shift (p = 0.011 for group 1 and p = 0.019 for group 2) but did not show significant differences at 3 months after surgery (p = 0.107 for group 1 and p = 0.760 for group 2). CONCLUSIONS: Combined IO anterior transposition procedures caused an increased change in the axis of induced astigmatism, including temporary incyclotorsion, during the first week after surgery. However, this significant difference was not maintained thereafter. Thus, combined IO surgery with LR recession does not seem to produce a sustained astigmatic change, which can be a potential risk factor of postoperative amblyopia or diplopia compared with LR recession alone.
Astigmatism/diagnosis/*etiology/physiopathology ; Child ; Exotropia/diagnosis/physiopathology/*surgery ; Eye Movements/*physiology ; Female ; Follow-Up Studies ; Humans ; Male ; Oculomotor Muscles/*surgery ; Ophthalmologic Surgical Procedures/*methods ; Retrospective Studies ; Treatment Outcome ; Vision, Binocular/*physiology

PURPOSE: To evaluate the efficacy and safety of customized orbital decompression surgery combined with eyelid surgery or strabismus surgery for mild to moderate thyroid-associated ophthalmopathy (TAO). METHODS: Twenty-seven consecutive subjects who were treated surgically for proptosis with disfigurement or diplopia after medical therapy from September 2009 to July 2012 were included in the analysis. Customized orbital decompression surgery with correction of eyelid retraction and extraocular movement disorders was simultaneously performed. The patients had a minimum preoperative period of 3 months of stable range of ocular motility and eyelid position. All patients had inactive TAO and were euthyroid at the time of operation. Preoperative and postoperative examinations, including vision, margin reflex distance, Hertel exophthalmometry, ocular motility, visual fields, Goldmann perimetry, and subject assessment of the procedure, were performed in all patients. Data were analyzed using paired t-test (PASW Statistics ver. 18.0). RESULTS: Forty-nine decompressions were performed on 27 subjects (16 females, 11 males; mean age, 36.6 +/- 11.6 years). Twenty-two patients underwent bilateral operations; five required only unilateral orbital decompression. An average proptosis of 15.6 +/- 2.2 mm (p = 0.00) was achieved, with a mean preoperative Hertel measurement of 17.6 +/- 2.2 mm. Ocular motility was corrected through recession of the extraocular muscle in three cases, and no new-onset diplopia or aggravated diplopia was noted. The binocular single vision field increased in all patients. Eyelid retraction correction surgery was simultaneously performed in the same surgical session in 10 of 49 cases, and strabismus and eyelid retraction surgery were performed in the same surgical session in two cases. Margin reflex distance decreased from a preoperative average of 4.3 +/- 0.8 to 3.8 +/- 0.5 mm postoperatively. CONCLUSIONS: The customized orbital decompression procedure decreased proptosis and improved diplopia, in a range comparable to those achieved through more stepwise techniques, and had favorable cosmetic results when combined with eyelid surgery or strabismus surgery for mild to moderate TAO.
Adolescent ; Adult ; Decompression, Surgical/*methods ; Exophthalmos/*surgery ; Eye Movements/physiology ; Eyelids/*surgery ; Female ; Graves Ophthalmopathy/*surgery ; Humans ; Male ; Middle Aged ; Oculomotor Muscles/surgery ; *Ophthalmologic Surgical Procedures ; Orbit/*surgery ; Retrospective Studies ; Strabismus/*surgery ; Visual Field Tests ; Visual Fields/physiology

PURPOSE: The purpose of this study is to compare the surgical outcomes and near stereoacuities after unilateral medial rectus (MR) muscle resection and lateral rectus (LR) recession according to deviation angle in basic intermittent exotropia, X(T). METHODS: Ninety patients with basic type X(T) were included in this study. They underwent unilateral recession of the LR and resection of the MR and were followed postoperatively for at least 12 months. Patients were divided into three groups according to their preoperative deviation angle: group 1 < or =20 prism diopter (PD), 20 PD< group 2 <40 PD, and group 3 > or =40 PD. Surgical outcomes and near stereoacuities one year after surgery were evaluated. Surgical success was defined as having a deviation angle range within +/-10 PD for both near and distance fixation. RESULTS: Among 90 patients, groups 1, 2, and 3 included 30 patients each. The mean age in groups 1, 2, and 3 was 9.4 years, 9.4 years, and 11.0 years, respectively. The surgical success rates one year after surgery for groups 1, 2, and 3 were 80.0%, 73.3%, and 73.3% (chi-square test, p = 0.769), respectively. The undercorrection rates for groups 1, 2, and 3 were 16.7%, 23.3%, and 26.7%, and the overcorrection rates were 3.3%, 3.3%, and 0%, respectively. The mean preoperative near stereoacuities for groups 1, 2, and 3 were 224.3 arcsec, 302.0 arcsec, and 1,107.3 arcsec, and the mean postoperative near stereoacuities were 218.3 arcsec, 214.7 arcsec, and 743.0 arcsec (paired t-test; p = 0.858, p = 0.379, p = 0.083), respectively. CONCLUSIONS: In basic X(T) patients, the amount of angle deviation has no influence on surgical outcomes in unilateral LR recession and MR resection. The near stereoacuities by one year after LR recession and MR resection for intermittent X(T) were not different among patient groups separated by preoperative deviation angle.
Child ; Exotropia/physiopathology/*surgery ; Female ; Follow-Up Studies ; Humans ; Male ; Oculomotor Muscles/physiopathology/*surgery ; *Ophthalmologic Surgical Procedures ; Retrospective Studies ; Treatment Outcome ; Vision, Binocular/physiology ; Visual Acuity/physiology

PURPOSE: The purpose of this study was to establish a set of normative data values for saccade movements using videonystagmography and to evaluate the effects of manual correction on this data. METHODS: We examined 25 healthy subjects (9 men and 16 women). All tests were carried out by one well-instructed physician. Errors such as the wrong detection of the inflection point, missing movement, and prediction occurred during some tests. Thus, the same physician manually corrected the data by deleting error data from row results. RESULTS: We established a set of normative data for horizontal saccade movements (amplitude size 15 and 30 degrees) for mean peak velocity, latency, and accuracy. Manual correction only impacted latency and accuracy at 30 degrees horizontal, which is likely related to possible errors during the test. CONCLUSIONS: The present study provides clinically useful videonystagmography-based normative data for clinicians regarding saccade movements in Korean individuals.
Adult ; Female ; Healthy Volunteers ; Humans ; Male ; Oculomotor Muscles/*physiology ; Photic Stimulation ; Reference Values ; Reproducibility of Results ; Saccades/*physiology ; Video Recording/*methods ; Young Adult

PURPOSE: To evaluate the results of levator resection in patients with myopathic ptosis. METHODS: The medical records of consecutive patients who underwent levator resection surgery performed for myopathic ptosis between October 2009 and March 2013 were reviewed. Indications for surgery were ptosis obscuring the visual axis and margin-reflex distance < or =2 mm. Surgical success was defined as clear pupillary axis when the patient voluntarily opened his eye and margin-reflex distance > or =3 mm. We analyzed the effect of levator function and Bell's phenomenon on the rates of success and corneal complication. RESULTS: This series included six male and six female patients. Levator function was between 4 and 12 mm. We performed bilateral levator resection surgery in all patients. The mean follow-up time was 14.8 months (range, 6 to 36 months). No patient was overcorrected. Adequate lid elevation was achieved after the operation in 20 eyes. Ptosis recurred in three out of 20 eyes after adequate lid elevation was achieved. Our overall success rate was 70.8%. In three eyes with poor Bell's phenomenon, corneal irritation and punctate epitheliopathy that required artificial eye drops and ointments developed in the early postoperative period, although symptoms resolved completely within 2 months of the resection surgery. No patients required levator recession or any other revision surgery for lagophthalmos or corneal exposure after levator resection. CONCLUSIONS: Levator resection seems to be a safe and effective procedure in myopathic patients with moderate or good Bell's phenomenon and levator function greater than 5 mm.
Adult ; Aged ; Blepharoptosis/*surgery ; Blinking/physiology ; Female ; Humans ; Male ; Middle Aged ; Muscular Diseases/*surgery ; Oculomotor Muscles/*surgery ; *Ophthalmologic Surgical Procedures ; Postoperative Complications