Changes in Angular Deviations under General Anesthesia for Strabismus Surgery with Objective Anesthetic Depth Control

PURPOSE: Changes in angular deviation before and after general anesthesia and strabismus surgery were examined. METHODS: Twenty patients with intermittent exotropia who were operated on by the same surgeon from January 2014 to October 2017 were included. The basic angle of deviation (preoperative angle of deviation, PreAn) was measured at an outpatient clinic. While lying on a surgical bed under general anesthesia, the bispectral index was referenced, and it was confirmed that there was a sufficient degree of sedation. Photographs were then taken at a height of 40 cm (angle of deviation under general anesthesia, PostAn); while still under general anesthesia, the same procedure was followed immediately after the end of surgery. At 6 months after surgery, the angle of deviation was measured. RESULTS: There were 10 males and 10 females, and the mean age was 7.31 ± 3.59 years. The preoperative angle of deviation was 30.0 ± 13.87 prism diopters (PD) at far fixation; under general anesthesia, 26.46 ± 5.39 PD. There was a significantly positive correlation between the PreAn and angle of deviation under general anesthesia (PostAn - PreAn = −7.67 × PreAn + 19.57; R2 = 0.872; p < 0.00). The angle of deviation changes between pre- and post-anesthesia (PostAn-PreAn) and at the end point of surgery (OP end) and at 6 months after surgery (6mon) also showed a significantly positive correlation (6mon-OP end = 0.317 × [PostAn - PreAn] + 13.098; R2 = 0.334; p = 0.01). CONCLUSIONS: There was a significant positive correlation between the measured angle of deviation pre- and post-anesthesia. We could estimate the degree of change between the angle of deviation immediately after surgery and the stable angle according to the degree of deviation before and after general anesthesia.

Variability of Preoperative Angle of Deviation Measured on the Day of Surgery in Intermittent Exotropia

PURPOSE: To evaluate the characteristics and surgical outcomes of children with intermittent exotropia whose preoperative angle of deviation changed on the day of surgery. METHODS: The medical records of 323 children with intermittent exotropia who underwent lateral rectus recession in both eyes were reviewed. The records were classified according to the difference of 8 prism diopters (PD) or more between the largest angle of deviation measured within 3 months prior to the operation and that on the day of surgery into the increased, same, or decreased groups. The frequency, characteristics, and surgical outcomes of each group were analyzed. The surgical amount was determined based on the largest angle of deviation measured at distance within 3 months before surgery. RESULTS: The angle of deviation at distance on the day of surgery was increased in 5 patients (1.5%) and decreased in 6 (1.9%). The near angle was increased in 19 (5.9%) and decreased in 22 (6.8%) patients. The groups in which distant deviation was changed had a greater distant angle and more patients with anisometropia. The group in which near deviation decreased was older than the same group and 81.8% of the patients were school-aged. In the group with changes in either distant or near deviation, the angle on the day of surgery changed toward decreasing disparity of near-distant deviation. On the last follow-up, the rate of overcorrection of 10 PD or more was 13.6% in the decreased near deviation group, which was significantly high (p = 0.039). CONCLUSIONS: The angle of deviation on the day of surgery could be different compared to the largest preoperative angle in some patients with intermittent exotropia. In patients with decreased near deviation, the rate of postoperative overcorrection might be high.

Comparison of Surgical Outcomes with Unilateral Recession and Resection According to Angle of Deviation in Basic Intermittent Exotropia

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 =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.

Comparison of Surgical Outcomes in Patients with Small Refractive Error and Intermittent Exotropia

PURPOSE: To identify differences in the refractive error of postoperative intermittent exotropia patients. METHODS: A total of 71 patients who had an average refractive error of 2 D and a follow-up of more than 6 months after unilateral recession-resection (R&R) for intermittent exotropia were included in this study. Patients were divided into 3 groups according to their refractive error: Group 1, or =+1.0 D. The amounts of deviation 1 day after surgery and 6 months after surgery were evaluated. RESULTS: Out of the 71 total patients included in this study, group 1 included 20 patients, group 2 included 39, and group 3 included 12. The average refractive error in groups 1, 2, and 3 was -2.2 +/- 0.9 D, 0.0 +/- 0.4 D and +1.9 +/- 0.9 D, respectively. The angle of deviation 1 day after surgery was measured in the 3 groups; A result labeled '+' was considered to be exodeviation and a result labeled '-' was considered to be esodeviation. The angle of deviation results for groups 1, 2, and 3 one day after surgery were -6.7 +/- 6.0 PD, -7.5 +/- 5.8 PD and -7.3 +/- 5.9 PD (p = 0.937), respectively, and the results 6 months after surgery were +2.2 +/- 4.3 PD, +4.7 +/- 5.9 PD and +1.8 +/- 2.8 PD (p = 0.076), respectively. Among the 3 groups, no statistically significant difference was observed in postoperative angle of deviation after 6 months. CONCLUSIONS: In basic intermittent exotropia patients with an average refractive error of 2 D, the amount of refractive error makes no difference in strabismus surgical outcomes.

Estereopsia en pacientes operados de exotropía intermitente / Stereopsis in patients operated on from intermittent exotropia

Métodos: se realizó un estudio descriptivo y prospectivo de enero de 2009 a diciembre de 2010 en el Servicio de Oftalmología Pediátrica del Instituto Cubano de Oftalmología Ramón Pando Ferrer. Se estudiaron 17 pacientes, entre 5 y 10 años de edad, operados de exotropía intermitente con agudeza visual mejor corregida mayor de 0,4. Se analizaron las variables: edad en el momento de la cirugía, sexo, la desviación en dioptrías prismáticas y la visión estereoscópica cercana medida por TNO, antes de la cirugía y a los 6 meses...

Methods: a prospective descriptive study carried out from January 2009 to December 2010 at the pediatric ophthalmology service of Ramón Pando Ferrer Cuban Institute of Ophthalmology. Seventeen patients aged 5 to 10 years, who had been operated on from intermittent exotropia and with best corrected visual acuity greater than 0.4, were studied. Those variables such as age at the time of surgery, sex, angle of deviation in prism diopters (PD) and near stereoscopic visual acuity measured by the TNO preoperatively and after 6 months...

The Surgical Outcome of Partially Accommodative Esotropia with a Large Angle of Deviation

PURPOSE: To investigate the surgical outcome of patients with partially accommodative esotropia with a large angle of deviation. METHODS: Twenty-one patients with partially accommodative esotropia that had angles of deviation of at least 40 prism diopters without correction, were retrospectively studied. They underwent standard surgery, for which the amount of recession was based on the average of the distance and near deviation with correction. The angle of deviation were evaluated at postoperative 3 months and at the last follow-up, and the Titmus test and Worth 4-dot test were performed after surgery. RESULTS: The mean angle of deviation without correction at the first examination was 57.0PD, and the mean age of correction with glasses was 2.6 years. The mean angle of deviation with correction was 31.4PD. The mean age at surgery was 4.4 years. The mean follow-up period was 5.4 years. At 3 months postoperatively, 66.7%, 28.6%, and 4.8% of patients showed acceptable correction, undercorrection, and overcorrection, respectively. At the last visit, undercorrection decreased while overcorrection increased (66.7%, 23.8%, 9.5%). Titmus stereotest showed in positive results with more than 800 seconds of arc in 9 of 16 patients. A Worth 4-dot test resulted in a fusion response at far or at near in 4 of 17 patients. CONCLUSIONS: In partially accommodative esotropia with a large angle of deviation (at least 40PD without correction), the results of conventional surgery were relatively fair, while the prognosis of sensory function was poor.

Surgical Result of Intermittent Exotropia According to Angle of Deviation at Lateral Gaze

PURPOSE: This study investigated the surgical result of intermittent exotropia according to the difference between primary gaze and lateral gaze, where the extent of surgical treatment was decided by the angle of deviation in primary gaze. METHODS: The subjects of this study were 128 patients who had intermittent exotropia and were operated on by the same surgeon. Deviation angle of strabismus was checked at near and distance and primary and 30-degree lateral directions of gaze. The Worth 4 dot test and Titmus test were performed. Refixation time and axial length were measured. Either the cycloplegic refraction test or manifest refraction test was done depending on the patient's age. The extent of surgery was decided by the criteria recommended by Parks. Patients were classified into 2 groups. Group 1 included patients with 5-PD or smaller differences in the angle of deviation in the primary and lateral gaze. Patients who had differences greater than 5-PD in the angle of deviation according to the direction of gaze were classified as group 2. Clinical data were verified by Pearson Chi-square test. RESULTS: Age, sex, angle of deviation at near and distance, oblique muscle function, spherical equivalent, astigmatism, axial length, stereopsis, and refixation time did not affect the difference in the angle of deviation according to the direction of gaze. The non-fusion group showed a large difference in the angle of deviation according to the direction of gaze. The extent of surgery was determined by the deviation angle in primary gaze. Both group showed similar surgical results. CONCLUSIONS: To determine the degree of surgery needed, it is reasonable to measure the deviation angle in primary gaze for patients with intermittent exotropia.

Infantile Esotropia

Authors reviewed 53 infantile esotropia patients in 218 patients who had undergone surgery for esotropia from January, 1986 to March, 1988. Of 53 patients, male were 29(54.7%) and female were 24(45.3%). Age when first seen by us ranged from 6 months to 12 years and 4 months. Patients with age below 2 years old were 28(52.7%). 32 patients(60.4%) had alternate fixation and 21 patients(39.6%) had monocular fixation. Angle of deviation over 35 prism diopters was found in 41 patients(77.4%). By cycloplegic refraction, of 106 eyes, 81 eyes(76.4%) were low hyperopes(plano - +3.0D). Associated clinical findings were inferior oblique overactions in 37 patients(69.8%), dissociated vertical divergences in 18 patients(34.0%), latent nystagmus in 3 patients(5.7%), superior oblique overaction in 1 patient(1.9%). The monocular recession and resection was performed as an initial surgical procedure. If a second procedure was required, same procedure was performed in the fellow eye. In the patients with inferior oblique overaction, inferior oblique myectomy was performed. Mean age at the time of operation was 4 years and 2 months. After surgery, of 53 patients, 45 patients were followed up for 6 months or over. Of 45 patients, postoperative angle within 10 prism diopters of orthophoria was found in 16(35.6%) after initial operation and in 33(73.3%) after reoperation. In patients with large angle of esodeviation(greater than 40 prism diopters), 6mm recession seemed to provide better results than 5mm recession after initial recess-resect procedure.