In robot-assisted eye surgery, such as retinal vascular bypass surgery, precise positioning of operating points is required. In this study, a binocular vision-based 3D reconstruction method is proposed to locate the incision points on retinal vessels. Vessels in the image were extracted by CLAHE algorithm to remove the influence of background, then stereo matching was performed. Finally, the retinal vessel image was reconstructed by using the principle of parallax in binocular vision. Experimental results show that this method can accurately locate the incision points on retinal vessels and meet the requirements of ophthalmic surgery.
Algorithms ; Humans ; Imaging, Three-Dimensional ; Ophthalmologic Surgical Procedures ; Retinal Vessels/diagnostic imaging* ; Robotic Surgical Procedures ; Vision, Binocular

Objectives: Refractive changes have been studied after muscle surgery in literature but most results are inconsistent. It has been postulated that changes in corneal tension after muscle surgery may cause a change in corneal curvature resulting in the change in refraction postoperatively. This study investigated changes in corneal topography and clinical refraction after horizontal rectus muscle surgery. Methods: Twenty-one eyes of 13 patients underwent horizontal rectus muscle surgery via limbal approach. Manifest refraction, cycloplegic refraction, and corneal topography were measured preoperatively, and postoperatively at day 1 and weeks 1, 2, 4 and 8. The proportion of subjects with at least 0.5 D change from preoperative measurements and the proportion of subjects that needed new prescription postoperative were also computed. Analysis of the results were done using the Friedman test to identify significant differences among measurements at different time periods with post-hoc analysis utilized to identify specific time periods with significant changes from preoperative measurements. Results: Mean corneal keratometry, horizontal, vertical, and oblique astigmatism, obtained topographically showed no significant difference from preoperative measurements. The statistically significant difference in corneal astigmatism in the recession group at day 1, week 4 and week 8 postoperatively was not confirmed when converted to power vectors in both vertical/horizontal (J0) and oblique (J45) astigmatism. Clinical refraction showed a transient myopic shift in spherical equivalent, statistically significant only on postoperative day 1 in the recession group. There was no statistically significant difference in clinical astigmatism. There was ≥ 0.5 D change in spherical equivalent in 60% in both study groups by the end of follow-up. The shift in J0 was more than 10% in the recession group. More than fifty percent (52.4%) needed new prescription for glasses. Conclusion No statistically significant change in corneal topography and clinical refraction following horizontal rectus muscle surgery were found. Patients should still be refracted at least 2 weeks postoperatively to check if there is a need for change in prescription glasses to improve alignment and/or improve vision.
Astigmatism ; Oculomotor Muscles ; Ophthalmologic Surgical Procedures ; Vision Tests ; Strabismus

BACKGROUND: A transcaruncular approach is typically used for reconstructions of medial wall fractures. However, others reported that a transconjunctival approach was conducive for securing an adequate surgical field of view. In this study, we aimed to examine the extent of repair of medial wall fracture via a transconjunctival approach. METHODS: We retrospectively reviewed the medical records of 50 patients diagnosed as having medial wall fracture via preoperative computed tomography and who underwent surgery between March 2011 and February 2014. The fracture location was defined by dividing each of the anterior-posterior and superior-inferior distances into three compartments. RESULTS: A transcaruncular approach was used in 7 patients, while the transconjunctival approach was performed in the remaining 43 patients. The transconjunctival approach enabled a relatively broad range of repair that partially included the front and back of the medial wall, and was successful in 86% of the entire study population. CONCLUSION: It is known that more than 50% of total cases of the medial wall fracture occur mainly in the middle-middle portion, a majority of which can be reconstructed via a transconjunctival approach. We used a transconjunctival approach in identifying the location of the fracture on image scans except for cases including the fracture of the superior portion in patients with medial wall fracture. If it is possible to identify the location of the fracture, a transconjunctival approach would be an useful method for the reconstruction in that it causes no damages to the lacrimal system and is useful in confirming the overall status of the floor.
Humans ; Medical Records ; Methods ; Ophthalmologic Surgical Procedures ; Orbital Fractures ; Orbital Implants ; Reconstructive Surgical Procedures ; Retrospective Studies

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

No abstract available.
Adult ; Anti-Bacterial Agents/*therapeutic use ; Chronic Disease ; Conjunctiva/*surgery ; Conjunctivitis/drug therapy/*surgery ; Female ; Follow-Up Studies ; Humans ; Ophthalmologic Surgical Procedures/*methods

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: We explored the performance of and pressure elevation caused by small-diameter microtubes used to reduce overfiltration. METHODS: Using a syringe pump-driven constant-flow setting (2 µL/min), pressures were measured for polytetrafluoroethylene (PTFE) microtubes 5 mm in length with inner diameters of 51, 64, and 76 µm and for polyether block amide (PEBAX) microtubes with an inner diameter of 76 µm. Experiments (using microtubes only) were initially performed in air, water, and enucleated pig eyes and were repeated under the same conditions using intraluminal 9/0 nylon stents. RESULTS: The pressures measured in air in 51-, 64-, and 76-µm-diameter PTFE microtubes differed significantly (22.1, 16.9, and 12.2 mmHg, respectively; p < 0.001), and that of the 76-µm-diameter PEBAX microtube was 15.8 mmHg (p < 0.001 compared to the 12.2 mmHg of the 76-µm-diameter PTFE microtube). The pressures measured in water also differed significantly among the three microtubes at 3.9, 3.0, and 1.4 mmHg, respectively, while that in the PEBAX microtube was 2.6 mmHg (all p < 0.001). Using the intraluminal stent, the pressure in water of the three different PTFE microtubes increased to 22.6, 18.0, and 4.1 mmHg, respectively, and that in the PEBAX microtube increased to 10.5 mmHg (all p < 0.001). Similar trends were evident when measurements were performed in pig eyes. CONCLUSIONS: Although microtubes of smaller diameter experienced higher pressure in air, reduction of the inner diameter to 51 µm did not adequately increase the pressure attained in water or pig eyes. Insertion of an intraluminal stent effectively elevated the latter pressures. PEBAX microtubes created higher pressures than did PTFE microtubes.
Animals ; Disease Models, Animal ; Glaucoma/physiopathology/*surgery ; *Glaucoma Drainage Implants ; Intraocular Pressure/*physiology ; Ophthalmologic Surgical Procedures/*instrumentation ; *Polytetrafluoroethylene ; Prosthesis Design ; Swine

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 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