Outcomes of a simplified, fixed surgical dosage calculation for uncomplicated, horizontal, concomitant strabismus in adults

Purpose: The aim of this study was to evaluate the outcomes of a simplified, fixed surgical dosage calculation for uncomplicated, horizontal, concomitant strabismus in adults. Methods: Outcomes analysis of a fixed?dose calculation method for uncomplicated, horizontal, concomitant strabismus in adults (?18 years) wherein 1?mm recession/resection equals 2 PD for lateral rectus and 3 PD for medial rectus. This was a retrospective case series. Results: The mean age of the patients was 28.50 � 8.43 years, the mean amount of preoperative deviation was 35.16 � 9.97 PD, the mean expected correction was 36.26 � 9.49 PD, and the mean correction achieved was 35.92 � 10.74 PD. There were 22 monocular exotropias, six monocular esotropias, eight alternate divergent squints, and two alternate convergent squints. There were 20 cases of sensory strabismus (54.28%). There was no statistically significant difference between the expected correction and correction achieved (P = 0.519), meaning that our fixed?dose calculation method was effective. Thirty?five out of 38 patients had successful outcomes as per our criteria of less than 10?PD deviations from straight in primary position. Therefore, the success rate achieved by this procedure was 92.10%. There was no statistically significant correlation between age and the amount of deviation (P = 0.611). Conclusion: Our case series had a high postoperative success rate in terms of motor alignment. It is hoped that this simplified, fixed?dosage calculation method would help the numerous novice strabismus surgeons, make their starting steps easier and give them the confidence to do strabismus surgeries. They can modify the dosages later as per their own experiences

Observation of modified fornix-based approach for minimal incision surgery in the treatment of children with the horizontal strabismus / 眼科新进展

Objective To evaluate the modified foruix-based technique with Guyton hook as an approach for the treatment of children with horizontal strabismus.Methods The clinical data of 128 patients (170 eyes) who underwent horizontal strabismus surgery between January 2014 and June 2017 were retrospectively reviewed,including 60 males and 68 females.The mean age was 1.5-17.0 (6.5 ± 1.6) years.All procedures under general anesthesia were performed using the modified fornix-based conjunctival incision with Guyton hook,and the follow-up period was 6 to 12 months.The clinical and cosmetic outcomes of strabismus surgery,the complications and interventions related to the incision were assessed.Results At 3 months after surgery,orthophoria with excellent cosmetics was achieved in 119 patients (93％) with the deviation ≤ ± 10△.Together 102 eyes (60％) had no intraoperative suture.Moreover,the incision was sutured with one stitch in 45 eye (26.5％),in 20 (11.8％) with 2 stitches,and in 3 (1.8％) with 3 stitches.During the follow up period,there was no severe intraoperative or postoperative complications.The swelling and redness of conjunctiva recovered quickly.Patients' discomfort was alleviated in a few days after the surgery.No oblivious scarring was found along the incision lines.Conclusion The modified fornix-based approach with Guyton hook is an effective and safe method for minimal incision surgery in children with horizontal strabis.

Clinical Manifestations of Inferior Oblique Overaction in Patients with Horizontal Strabismus

PURPOSE: To investigate the clinical manifestations of and the surgical success rates in patients with horizontal strabismus and inferior oblique overaction (IOOA). METHODS: The patients included in the present study had received myectomy for correction of IOOA and had at least 3 months of follow-up. The patients were divided into 2 groups; patients who received myectomy and surgery for horizontal strabismus simultaneously (combined group, 74 eyes of 49 patients) and patients who received myectomy only (myectomy group, 29 eyes of 24 patients). Chief complaints, head tilt, bilaterality of IOOA, ocular torsion, and the surgical success rates were analyzed. RESULTS: In the combined group, 51% of the chief complaints were horizontal deviation, and in the myectomy group 42% were upward deviation and 29% were head tilt. Objective head tilt was 29% in the combined group and 54% in the myectomy group and the difference was significant. There was no significant difference statistically in the success rate of myectomy. CONCLUSIONS: The frequency of symptoms associated with IOOA in the combined group was lower than in the myectomy group. Therefore, preoperative examination regarding IOOA should be carefully performed in patients who are planning a horizontal strabismus surgery because there was no difference in surgical success rate between the 2 groups, the association with horizontal strabismus may have no effect on the surgical results of IOOA.

Effect of Axial Length (Myopia) on Horizontal Recti Recession in Children with Horizontal Strabismus

PURPOSE: To assess the influence of axial length for surgical outcome of horizontal recti recession in children with horizontal strabismus. METHODS: A retrospective, non-comparative case series. 100 patients, 96 males and 44 females with unilateral or bilateral high myopia and strabismus surgery was performed. All patients had horizontal recti recession and no combined vertical strabismus. There was no history of any ocular trauma or surgery and no history of any other systemic diseases that affect ocular motility. After horizontal recti recession, the patients were followed-up for more than one year. Data was analyzed using SPSS Software for Windows, version 12.0.1. RESULTS: In 100 children, the mean axial length was 23.21 +/- 1.38 mm (range, 19.63-26.50 mm) and the mean age was 7.43 +/- 2.86 years (range, 1-14 years). Lateral rectus recession was in 89 cases, and medial rectus recession was done in 11 cases. After operation, 86 cases were fully corrected, 11 cases were under corrected and 3 cases were over corrected. Binary logistic regression analysis was performed revealing that, preoperative angle of deviation (p-value 0.062) and axial length (p-value 0.05) were highly correlated with surgical outcome. CONCLUSIONS: Age, preoperative angle of deviation, and axial length may influence the surgical outcome of horizontal recti recession in children. In eyes with long axial length, the surgical outcome of horizontal recti recession appears to be poorer than that in eyes with short axial lengths. Adjusting the recession amounts when performing horizontal recti recessions in long axial length eyes may provide better results.

Intraoperative Adjustment in Horizontal Strabismus Surgery Using Corneal Reflex

PURPOSE: Using corneal reflex, we performed intraoperative adjustments in horizontal strabismus patients who had very poor visual acuities with good compliance and analyzed various aspects of intraoperative adjustment. METHODS: We retrospectively reviewed the records of patients with horizontal strabismus who underwent intraoperative adjustment using corneal reflex from May 1997 to April 2005. We evaluated various aspects of intraoperative adjustment. RESULTS: Fifty-five patients (40 exotropes, 15 esotropes) were included in our study. 11 of 40 extropes (27.5%) and 4 of 15 esotropes (26.7%) eventually underwent operations that were adjusted intraoperatively. Successful results were seen in 35 of 40 exotropes (87.5%) and 8 of 15 esotropes (53.3%). Fifteen patients (27.3%) received intraoperative adjustments, and of these patients 11 (20.0%) who had successful results would have experienced either undercorrection or overcorrection if their operation were performed as scheduled. Four patients underwent operation on one muscle rather than on the scheduled two muscles. All 4 of these patients (100%) would have experienced significantly large overcorrection had they not received intraoperative adjustment. CONCLUSIONS: Patients who would have had difficulty with fixation due to low visual acuity could avoid under- or overcorrection and are expected to have higher success rates because of intraoperative adjustment using corneal reflex.

Characteristics and Outcome in Horizontal Strabismus Combined with Unilateral Superior Oblique Palsy

PURPOSE: To review the clinical characteristics and treatment outcomes in horizontal strabismus combined with unilateral superior oblique palsy (SOP). METHODS: A retrospective review of medical records was conducted in 21 patients with unilateral SOP treated between January 2001 and December 2005. Patients had more than 6 months of follow-up at the Department of Ophthalmology, Wonju College of Medicine. RESULTS: Among 21 patients (11 male, 10 female) with unilateral SOP, 57.1% of patients had horizontal strabismus. The mean vertical deviation was 12.56+/-3.81 (8~24) PD. All patients with horizontal strabismus had exotropia and the mean deviation was 10.57+/-4.58 (6~20) PD. A standard 10mm inferior oblique (IO) recession was performed uniformly at the paretic eye in all patients. In 7 of the patients (58.3%, exotropia greater than or equal to 10PD), horizontal rectus muscle recession was performed simultaneously. In these 7 cases, vertical and horizontal deviation less than or equal to 4PD was achieved (one patient with 10PD remaining hypertropia excluded). In 5 cases with exodeviation less than 10PD, isolated IO recession without horizontal rectus recession on the ipsilateral side achieved orthophoria in the primary position. In 9 cases of isolated SOP, all patients showed orthophoria in the primary position. CONCLUSIONS: This study demonstrates horizontal strabismus is combined with unilateral SOP in a high percentage of patients. Additionally, in all cases, all the incidents of horizontal deviation was involved exotropia. A standard 10 mm recession of the IO in combination with horizontal rectus recession is an effective surgical technique. It has an especially high success rate in patients with unilateral SOP (< or =14PD vertical deviation) with exodeviation greater than 10PD. In patients with exodeviation less than 10PD, an isolated IO recession is sufficiently effective.

Experiencia de cirugía dinámica en corrección de estrabismo horizontal / Dynamics surgery experience in horizontal strabismus correction

Objetivo: Describir nuestra experiencia con la técnica de cirugía dinámica para la corrección de estrabismo horizontal en el Complejo Hospitalario Metropolitano Dr. AAM con los pacientes operados de enero de 2002 a mayo de 2004. Metodología: Estudio descriptivo, retrospectivo, longitudinal del paciente con estrabismo horizontal sometidos a cirugía dinámica con evaluaciones post operatorias al primer mes, a los seis meses y al año. Se tomaron como variables tipo y grado de desviación pre y post operatoria, monocularidad-alternancia y la presencia de complicaciones postquirúrgicas. Resultados: Los resultados postquirúrgicos fueron satisfactorios tanto en el 1er mes, a los seis meses como al año (98 por ciento, 96 por ciento y 85 por ciento, respectivamente). Tanto los pacientes operados con diagnóstico de estrabismos monoculares como los alternantes mostraron resultados satisfactorios post operatorios al mes, a los 6 meses y al año. El porcentaje de complicaciones en nuestra serie fue de 11,7 por ciento (9 casos), con un predominio del estrabismo residual (6,5 por ciento). Conclusiones: En general, los resultados de la cirugía dinámica fueron satisfactorios en este estudio, tanto en el 1er mes (98 por ciento), a los 6 meses (96 por ciento) como al año (85 por ciento) post operatorios. No se encontraron diferencias significativas entre las evaluaciones al 1er mes, a los 6 meses y al año, lo que podría sugerir una tendencia a la estabilidad del resultado quirúrgico. No se encontraron diferencias significativas en los resultados post quirúrgicos de los pacientes tanto con estrabismos monoculares como con estrabismos alternantes.

Objective: To describe our experience on the technique of the dynamic surgery for the correction of horizontal strabismus in the Metropolitan Hospitalary Complex Dr. A.A.M. with patients operated between January of 2002 and may of 2004. Methodology: This is a descriptive, retrospective, longitudinal study of patients with horizontal strabismus who underwent dynamic surgery with post-operative evaluations at the first, sixth and twelfth month. Variables studied were: type and degree and pre and post-operative complications. Results: The post-operative results were satisfactory at the first, sixth and twelfth month, and they were 98 percent, 96 percent and 85 percent respectively. Operated patients with diagnosis of monocular strabismus as well patients who alternated, showed satisfactory results post-operatively at the first, sixth and twelfth month. The percentage of complications in our series was 11.7 percent (9 cases), with a predominance of residual strabismus. (6,5 percent) Conclusions: In general, the results of the dynamic surgery were satisfactory in this study, at the first month (98 percent), at the sixth month (96 percent) and at the twelfth month (86 percent) post-operatively. We did not find significant differences at the first, sixth or twelfth month, and this could suggest a tendency towards of stability the surgical result. We did not find significant differences in the post-operative results of patients with monocular strabismus or alternate strabismus.

Study on plication of horizontal recti to correct horizontal strabismus

Plication of horizontal recti with many advantages in the treatment of strabismus has been applied by many authors in the world, but not yet in Vietnam. Objectives: to evaluate the results of this surgery that applied in Vietnamese. Methods: Prescriptive, longitudinal prospective study that had been done in Hanoi National Institute of Ophthalmology from 9/2003 to 9/2004. Results: In postoperative period, 83.3% of cases with exotropia and 89.6% of cases with esotropia are well corrected after 6 months, 100% of operated eyes are well healed with a smooth conjunctive scars and 52.62 % of operated patients have got a full binocular vision after 3 months following up. The rate of the eyes with suspected amblyopia is reduced from 18.8% to 9.8%, with moderate amblyopia is also reduced from 8.8% to 2.4% by 6 months postoperatively, but the rate of the eyes with severe amblyopia is not significantly changed after surgery. Conclusion: Plication of horizontal recti is a safe, effective method for correction of strabismus, especially when it is necessary to do surgery on many extra-ocular muscles in the same eye.

Superior Oblique Palsy Combined with Horizontal Strabismus

PURPOSE: To investigate the clinical characteristics of superior oblique palsy in patients with horizontal strabismus. METHODS: Nineteen superior oblique palsy patients with vertical deviation or inferior oblique overaction who complained horizontal deviation were evaluated. Visual acuity, ocular movement test, prism cover test, Bielschowsky head tilt test, fundus photograph and examining photographs for head tilt and facial asymmetry were performed. Horizontal strabismus surgery and inferior oblique myectomy was done simultaneously , and the postoperative results was compared with preoperative condition. RESULTS: There were 15 exotropic patients (22.20PD+/-6.01SD) and 4 esotropic patients (22.00PD+/-12.08SD). Vertical deviation was found to be 6.74PD+/-3.35SD. Inferior oblique overaction (+0.5~2) was observed in 18 patients. Twelve patients had excyclotorsion. Of 18 patients with head tilting and 12 patients with facial asymmetry, seven patients (38.9%) in head tiltilng and six patients (50%) in facial asymmetry did not notice the abnormality. Horizontal strabismus surgery with inferior oblique myectomy showed good results in all cases. CONCLUSIONS: We should consider the possibility of superior oblique palsy when the patients showed small amount of vertical deviation, head tilt, facial asymmetry or monocular inferior oblique overaction combined with horizontal strabismus, and do the surgery simultaneously for horizontal strabismus and superior oblique palsy.

Stereopsis after Surgery in Longstanding Adult Horizontal Strabismus

Binocular function is not easy to obtain after strabismus surgery in adults with longstanding strabismus. In this study, postoperative binocular function was evaluated in 60 adults with longstanding horizontal strabismus. The subjects were eighteen years older and had developed strabismus before the age of eight. They were composed of 15 esotropes and 45exotropes without history of strabismus surgery. Pre-and postoperative stereopsis was assessed with Titmus-fly and Randot stereopsis tests. Visual acuity of the deviating eye, duration of deviation, angle of deviation, and status of stereopsis were compared according to the type of deviation. Stereopsis was shown in 20.0% of esotropes and 71.1% of exotropes before surgery. After surgery, only 46.7% of esotropes showed stereopsis in contrast with 91.1% of exotropes. In cases with congenital origin, 22.2% of esotropes and 83.3% of exotropes had stereopsis, while in those of acquired origin, 83.3%, and 92.3%, respectively. This study shows that stereopsis of good quality can be obtained and improved after surgery in adlts with longstanding horizontal strabismus except congenital esotropes. Higher gain of good postoperative stereopsis was related to better visual acuity of the deviating eye and shorter duration of deviation.

The Effect of Vertical Transposition of Horizontal Muscles on Vertical Deviation Associated with Horizontal Strabismus

The authors performed vertical transposition of the horizontal rectus muscles during monocular recession-resection surgery to correct the comitant vertical deviation associated with the horizontal strabismus. When the eye was hypertropic, infratransposition of horizontal rectus muscles was performed and when the eye was hypotropic, supratransposition of the insertions of the horizontal muscles was performed. For vertical strabisumus with 4 delta-12 delta(mean 7.7 delta) angle deviation, each medial and lateral rectus muscles were vertically transposed 2mm-4.5mm(mean 3.1mm) in 51 eyes. Fourty four eyes(86.3%) were vertically aligned, 4 eyes(7.8%) were undercorrected, and 3 eyes(5.9%) were overcorrected with 19.1 months of follow-up periods in average. By one millimeter vertical transposition of horizontal recti, vertical deviation was corrected by 1.21 delta in average. The vertical transposition of horizontal recti can be an effective method for correcting vertical deviation associated with horizontal strabismus not associated with any cyclovertical muscle dysfunction.

The Effect of Vertical Transposition of Horizontal Muscles on Vertical Deviation Associated with Horizontal Strabismus

The authors performed vertical transposition of the horizontal rectus muscles during monocular recession-resection surgery to correct the comitant vertical deviation associated with the horizontal strabismus. When the eye was hypertropic, infratransposition of horizontal rectus muscles was performed and when the eye was hypotropic, supratransposition of the insertions of the horizontal muscles was performed. For vertical strabisumus with 4 delta-12 delta(mean 7.7 delta) angle deviation, each medial and lateral rectus muscles were vertically transposed 2mm-4.5mm(mean 3.1mm) in 51 eyes. Fourty four eyes(86.3%) were vertically aligned, 4 eyes(7.8%) were undercorrected, and 3 eyes(5.9%) were overcorrected with 19.1 months of follow-up periods in average. By one millimeter vertical transposition of horizontal recti, vertical deviation was corrected by 1.21 delta in average. The vertical transposition of horizontal recti can be an effective method for correcting vertical deviation associated with horizontal strabismus not associated with any cyclovertical muscle dysfunction.

Binocular Fixation Patterns in Children with Horizontal Strabismus

In children with horizontal strabismus, we observed and analysed binocular fixation pattern (BFP) pf each eye and the results of BFP were compared with visual acuity of each eye to evaluate the effect of BFP examination for diagnosis of the preferred eye. In BFP of the esotropes and intermittent exotropes with or without amblyopa, most of patients showed grade I of BFP in the preferred eyes and grade IV of BFP in the non-preferred eyes. The exotropes showed no significant amblyopia, and BFP of the preferred eyes were variable from grade I to IV while most of the non-preferred eyes showed grade IV of BFP. In the patients with visual improvement after occlusion therapy, about half of them showed an improvement in BFP. Therefore, the preferred and non-preferred eyes may be distinctive according to BFP in strabismic patients with amblyopia or not. The measurement of BFP may be an eefective method for diagnosis of the preferred eye in children with horizontal strabismus if it is combinded with the examination for visual acuity.

Binocular Fixation Patterns in Children with Horizontal Strabismus

In children with horizontal strabismus, we observed and analysed binocular fixation pattern (BFP) pf each eye and the results of BFP were compared with visual acuity of each eye to evaluate the effect of BFP examination for diagnosis of the preferred eye. In BFP of the esotropes and intermittent exotropes with or without amblyopa, most of patients showed grade I of BFP in the preferred eyes and grade IV of BFP in the non-preferred eyes. The exotropes showed no significant amblyopia, and BFP of the preferred eyes were variable from grade I to IV while most of the non-preferred eyes showed grade IV of BFP. In the patients with visual improvement after occlusion therapy, about half of them showed an improvement in BFP. Therefore, the preferred and non-preferred eyes may be distinctive according to BFP in strabismic patients with amblyopia or not. The measurement of BFP may be an eefective method for diagnosis of the preferred eye in children with horizontal strabismus if it is combinded with the examination for visual acuity.

A Study of the Change in Angle Deviation under General Anesthesia in Horizontal Strabismus Patients

We measured the angle deviation by prism cover test before operating and by Hirschberg's method while under a surgical plane of anesthesia and studied the changes in 105 patients with uncomplicated comitant horizontal strabismus who underwent muscle surgery in the Department of Ophthalmology, Dongsan Medical Center, Keimyung University School of Medicine from June 1985 to February 1987. We excluded from the study those patients with previous muscle surgery, neurological disease, and those with mechanical restrictions of eye movement detected either by clinical examination or positive forced duction tests under general anesthesia, or both. The results were as follows: 1. Angle deviation at far was 28.7 +/- 13.8 delta in exotropia and 39.9 +/- 15.6 delta in esotropia, revealing a significantly larger angle deviation in esotropia than exotropla. 2. The change in angle deviation under general anesthesia showed a decrease in the amount of preoperative angle deviation of 15.5 +/- 12.0 delta in exotropia and 27.2 +/- 17.7 delta in esotropia, significantly more decreased in esotropia than in exotropia. The change according to sex and age was of no significance in exotropia and esotropia. 3. The relationship between the preoperative angle deviation at far(DF) and that under general anesthesia(DA) was linear and could be written as the approximate regression formula: DA=0.40DF+2.20(r=0.76). 4. The relationship between the preoperative angle deviation at far(DF) and the change in angle deviation under general anesthesia[D(A-F)] was linear and could be written as the approximate regression formula: D(A-F)=-0.60DF+2.20 (r= -0.87). The change in angle deviation under general anesthesia revealed a decrease in the amount of preoperative angle deviation both in exotropia and esotropia and, in general, the larger the preoperative angle deviation was, the greater was the change in angle deviation under general anesthesia. 5. In exotropia, the change in angle deviation under general anesthesia according to the difference between preoperative angle deviation at near and far was -14.4 +/- 11.9 delta in cases of larger angle deviation at near than far, -18.3 +/- 9.6 delta in cases of larger angle deviation at far than near, and -18.8 +/- 15.4 delta in cases of the same angle deviation at near and far, respectively, which was of no clinical significance. 6. In esotropia, the change in angle deviation under general anesthesia according to the difference between preoperative angle deviation at near and far was +26.7 +/- 14.3 delta in cases of larger angle deviation at near than far, +35.3 +/- 27.3 delta in cases of larger angle deviation at far than near, and +25.6 +/- 18.3 delta in cases of the same angle deviation at near and far, respectively, which again was of no clinical significance. Thus, our results suggest that the eye position under surgical anesthesia has a tendency to change toward the anatomical position of rest and the innervational imbalance may play a major role in the causation of horizontal strabismus. It seems to have no influence in changing the preoperative surgical plan on the basis of the change in angle deviation under general anesthesia in horizontal strabismus patients.