Comportamiento clínico quirúrgico de la exotropía de gran ángulo / Clinical and surgical behavior of large-angle exotropia

RESUMEN Objetivos: Describir algunas características clínicas de la exotropía de gran ángulo y determinar su resultado quirúrgico. Métodos: Se realizó un estudio descriptivo retrospectivo de 35 pacientes atendidos en el Hospital Oftalmológico "Amistad Cuba-Argelia", en la Wilaya de Ouargla, Argelia, en el período enero 2014 - diciembre 2017. Se analizó el comportamiento de algunas variables relacionadas con la exotropía, como fueron la edad del paciente, el sexo, el color de la piel, las alteraciones oftalmológicas asociadas, el grado de ambliopía, el defecto refractivo asociado, el ángulo de desviación preoperatorio y posoperatorio y el tipo de cirugía realizada. Resultados: Predominó el grupo etario entre 24 y 29 años de edad con el 25,7 por ciento; el 51,4 por ciento representó al sexo femenino; el color de la piel negra fue el más frecuente con 48,6 por ciento; la ptosis palpebral correspondió al 11,4 por ciento de las alteraciones oftalmológicas asociadas y al 68,6 por ciento sin alteraciones; la ambliopía moderada se registró en el 42,9 por ciento de los casos; el defecto refractivo más observado fue el astigmatismo miópico con el 37,1 por ciento; el ángulo de desviación preoperatorio más significativo se encontró en el grupo de 71-80 dioptrías con 37,2 por ciento. A los tres meses de la cirugía el 91,4 por ciento de los pacientes se encontró en ortoforia (± 8 dioptrías) y al año de la cirugía el 94,3 por ciento se mantenía en ortoforia. El retroceso de ambos músculos rectos laterales (10,0 mm) más la resección de un músculo recto medio (7 mm) se realizó en el 37,2 por ciento de los pacientes. Conclusiones: La casi totalidad de los pacientes con exotropía de gran ángulo logran el alineamiento ocular y consiguen una mejoría en la calidad visual(AU)

ABSTRACT Objectives: Describe some clinical characteristics of large-angle exotropia and determine its surgical outcome. Methods: A retrospective descriptive study was conducted of 35 patients attending Cuba-Algeria Friendship Ophthalmological Hospital in the wilayah of Ouargla, Algeria, from January 2014 to December 2017. Analysis was carried out of variables related to exotropia, such as the patients' age, sex, skin color, associated ophthalmological alterations, degree of amblyopia, associated refractive defect, pre- and post-operative angle of deviation, and type of surgery performed. Results: The 24-29 year age group prevailed with 25.7 percent; 51.4 percent of the patients were female; black skin color was the most common with 48.6 percent; eyelid ptosis represented 11.4 percent of the associated ophthalmological alterations and 68.6 percent without alteration; moderate amblyopia was present in 42.9 percent of the cases; the most frequent refractive defect was myopic astigmatism with 37.1 percent; the most significant preoperative angle of deviation was found in the 71-80 diopter group with 37.2 percent. Three months after surgery, 91.4 percent of the patients were orthophoria (± 8 diopters) and at one year 94.3 percent remained orthophoria. Bilateral lateral rectus muscle recession (10.0 mm) plus resection of a medial rectus muscle (7 mm) was achieved in 37.2 percent of the patients. Conclusions: Practically all patients achieved ocular alignment and improved their visual quality(AU)

Comparison of the Outcomes of Two- and Three-muscle Surgery in Exotropia over 45 Prism Diopters

PURPOSE: We report the outcomes of two- or three-muscle surgery on patients with large-angle exotropia exceeding 45 prism diopters (PDs). METHODS: We retrospectively analyzed data on 45 exotropia patients (> 45 PDs) who underwent two- or three-muscle surgery. We excluded patients with paralytic or restrictive strabismus, A- or V-pattern strabismus, a coexistent oblique dysfunction or nystagmus, and/or a history of prior extraocular muscle surgery. Only patients for whom at least 6 months of follow-up data were available were included. Successful surgery was defined as postoperative esotropia ≤ 5 PD, orthophoria, and exotropia ≤ 10 PD at the last visit. RESULTS: We included 45 patients, of whom 22 and 23 underwent two- and three-muscle surgery, respectively. The mean postoperative deviations were 9.5 and 2.7 PD in the two- and three-muscle groups, respectively; the overall success rates were 54.55% (12/22) and 91.30% (21/23). Subgroup analyses revealed that the surgical success rate of two-muscle operations was 66.67% (12/18) in 45–55 PD patients and 0% (0/4) in ≥ 55 PD patients; the success rates of three-muscle operations were 100% (7/7) and 87.50% (14/16). The success rate did not differ significantly between those with postoperative deviations of 45–55 PD (p = 0.137), but did between those who underwent two- and three-muscle operations to treat postoperative deviations of ≥ 55 PD (p = 0.003). CONCLUSIONS: Satisfactory results can be achieved via two-muscle surgery in patients with exotropia 55 PD, three-muscle surgery is superior to two-muscle surgery. Therefore, large-angle exotropia is optimally treated via three-muscle surgery.

Surgical Outcomes of Large-Angle Exotropia

PURPOSE: To examine the surgical results of large-angle exodeviations over 30 prism diopters (PD) and correlation factors influencing surgical outcomes. METHODS: The authors retrospectively examined 63 patients with an exodeviation greater than 30 PD. All patients were examined for at least six months after the operation. Near and far deviation angles, age at operation, operation method, and alignment at postoperative one week, one month, three months and six months were analyzed as factors influencing the surgical outcome. RESULTS: The preoperative deviation was 35 to 40 PD (38.1%) in most cases. Forty-five patients underwent bilateral lateral rectus recession, 16 patients underwent unilateral medial rectus resection and lateral rectus recession, and two patients underwent surgery on three different muscles. Success was defined as sustained alignment from esotropia 10 PD to exotropia 10 PD. The success rate was 79.4% at the first week, 77.8% at one month, 73.0% at three months, and 68.3% at six months postoperatively. In particular, the success rate was significantly lower at six months postoperatively in the group with exotropia greater than 45 PD (36.4%). The patients with esotropia on the first postoperative week showed a significantly high success rate (86.6%); however, neither the age at operation nor the operation method affected the surgical results. CONCLUSIONS: Large-angle exodeviations can be successfully approached with a single operation, with a success rate of 68.3% at six months postoperatively. Esotropia of less than 10 PD at the first postoperative week shows the most ideal surgical results. For patients having exodeviations greater than 45 PD, the success rate will decrease over time. Therefore, surgeons should carefully plan for large-angle exodeviation surgery.

The Accuracy of Estimating Postoperative Deviation in Exotropia With over 40 Prism Diopters

PURPOSE: To assess the accuracy of estimating postoperative deviation in large-angle exotropia over 40 prism diopters (PD). METHODS: A retrospective analysis was performed on 61 exotropia patients with over 40 PD exotropia who had undergone 2-muscle surgery by two surgeons and with at least 6 months follow-up. The accuracy was assessed by analyzing the discrepancy between preoperatively predicted residual deviation and deviation at postoperative 6weeks. Successful surgery was defined as deviation within +/- 10 PD at the last postoperative visit. RESULTS: More accurate residual deviation was predicted in exotropia with prism diopters between 40 and 59 (97.8%) than in exotropia with 60 PD or more (62.5%). And there was no significant difference between two surgeons. Surgical success rates at six months and one year after surgery were 96.8%, 94.7% in exotropia with 40 to 49 PD, 71.4%, 60.0%, 50 to 59 PD, 50.0%, 45.5%, 60 PD or more, respectively. There were four patients of whom the postoperative deviation angle exceeded more than 10 PD of the estimated deviation. CONCLUSIONS: The accuracy of estimating residual deviation prior to surgery was higher and more successful surgery was achieved in exotropia ranging in 40 to 59 PD than in exotropia with 60 PD or more. Therefore, 2- muscle surgery will be suitable for large-angle exotropia with less than 60 PD.

Treatment of Exotropia Caused by Lost Medial Rectus Muscle

PURPOSE: We report three patients with large angle exotropia had lost medial rectus muscle (MR) and who attained good alignment postoperatively. METHODS: Patient 1 was a 51-year-old female with a history of strabismus surgery done at 10 years of age. Exotropia of 80 prism diopter (PD) gradually developed with limitation of adduction in the right eye. Patient 2 was a 52-year-old male with fixed exotropia of 95 PD in his left eye, which became blind after a severe contusion injury. The third patient was a 46-year-old male who had MR of the right eye cut during endoscopic sinus surgery. Severe limitation of adduction followed with exotropia of 50 PD. We could not find MR in any of the three patients and noted severe adhesion between eyeball and Tenon's capsule. Ocular movement was severely limited horizontally and even vertically. RESULTS: Postoperatively Patient 1 showed orthophoria in follow-up of 2 years. Patient 2 had 16PD of exotropia in follow-up of 13 months, which was cosmetically acceptable. Patient 3 obtained orthophoria after surgery and developed 10 degrees of left head turning to avoid diplopia. CONCLUSIONS: When a patient shows longstanding large angle exotropia with limitation of adduction, we may consider the MR loss. A reasonable treatment may be to align the eyes cosmetically in primary position by weakening the abducting power and suturing the anterior part of nasal Tenon's capsule to the MR insertion site after adhesiolysis.

Effects of Bilateral Lateral Rectus Recession and Unilateral Recession-Resection in Large Angle Exotropia

PURPOSE: To evaluate the effect of bilateral lateral rectus recession and of unilateral rectus recession and resection in the patients who showed large angle exotropia. METHODS: Sixty-five patients who underwent either bilateral lateral rectus recession or unilateral recession-resection and who were followed up for more than 1 year between 1996 to 2001 at Chonnam University Hospital, were reviewed. The effect of bilateral lateral recession and unilateral recession-resection was compared according to preoperative angle of deviation. Successful outcome was defined as esotropia

Effect of Both Lateral Rectus Recession in Large Angle Exotropia

PURPOSE: To evaluate of the effect of both lateral rectus recession according to the amount of the recession in the patients who showed large angle (>or=35 prism diopter, PD) exotropia. METHODS: The 120 patients who underwent both lateral rectus recession and followed up more than 1 year between 1996 to 2002 at Chung-nam university hospital, were reviewed. The effect of both lateral rectus recession was compared according to the amount of recession and preoperative angle of deviation. Successful outcome was defined as esotropia

The Surgical Outcome of Bilateral Lateral Rectus Recession in Large Angle Exotropia

To evaluate the results of bilateral recession in large angle exotropia we examined medical records of 73 patients who had exotropia larger than 35PD and underwent bilateral lateral rectus recession. The mean of follow-up period was 16months. Successful alignment, defined as a final alignment of orthophoria, esotropia less than 5PD or exotropia less than 10PD was achieved in 44 patients(60.3%). There were no differences in age, refractive error, preoperative angle of deviation, prevalence of amblyopia, the presence and concurrent correction of vertical or cyclodeviation, the development of diplopia and the duration of follow-up period between the successful alignment group and failure group. The esodeviation on postoperative one-day tended to ensure a more satisfactory result, but it was not statistically significant. There were no statistically significant differences in stereoacuity and postoperative angle of deviation among the different fusional ability groups. The stereoacuity and postoperative angle of deviation did not show a positive correlation. However, on the two separate examinations of the stereoacuity and fusional ability, the latter results showed improvement in both parameters. This result suggests that the correction of exodeviation may play a role in improving binocular visual function in patients with large angle exotropia.

Comparison of Surgical Results Between Bilateral Rectus Muscle Recession and Lateral Rectus Muscle Recession and Medial Rectus Muscle Resection in Exotropia Over 40 Prism Diopters

It is the purpose of this study to compare the postoperative results of 168 patients with exotropia of basic and simulated divergence excess type over 40 prism diopters; 86 patients had bilateral rectus muscle recessions and 82 patients underwent lateral rectus muscle recession and medial rectus muscle resection. The patients in the former group had averaged 13.7 years of age and 8.2 months of postoperative follow-up period. Those in the latter group averaged 22.9 years and had been followed up for 7.1 months. The postoperative success rates are as follows: 66.7%(57/86) in the bilateral rectus muscle recession group and 68.1%(58/82) in the lateral rectus muscle recession and medial rectus muscle resection group(P>0.05). And the success rates of those older than 16 years without amblyopia are 60.0%(18/30) in the former group and 75.0%(24/32) in the latter group(P>0.05). The lateral rectus muscle recession and medial rectus muscle resection group showed somewhat higher rates of success even though it proved statistically insignificant.

Recognition and Repair of the Slipped Muscle

Eight consecutive case of the slipped muscle are recognized and treated with the surgical intervention. All patients showed a large-angle exotropia(30 - 70 prism diopter), moderative to severe degree of limitation of adduction(-1.5 - -3) and negative forced duction test. Intraoperatively, we could identify the empty muscle capsule attached to the sclera with the tendon slipped posteriorly within its capsule. Repair is accomplished by resecting the empty capsule and advancing the true tendon to or toward the original insertion. After the average follow up period of 36.1 weeks, the amount of reduced within 10 prism diopters and limitation of duction within-0.5 in all patients. A better understanding of the pathology may lead to early diagnosis and surgical repair, and then the prognosis for functional and cosmetic result will be excellent.