Results of fusional vergence therapy in managing consecutive esotropia: A case series

Purpose: To analyze the efficacy of fusional vergence therapy (FVT) in management of consecutive esotropia with diplopia after intermittent exotropia (IXT) surgery. The current study is carried on how FVT affects the duration of treatment, sensory fusion, and exotropic drift. Methods: This was a retrospective study for the medical record of 11 patients with consecutive esotropia after IXT surgery of 543 patients over the period of 5 year, with mean surgery age of 9.5 (range: 4–33 y). FVT was planned after minimum 6 weeks of surgery and was considered for maximum 24 weeks. Patients underwent a combination of office-based and home-based FVT. Successful outcome of therapy was considered where diplopia resolves in free space and achieves sensory fusion, stereopsis with no manifest deviation. Results: Record of 543 patients who had horizontal muscle surgery for IXT were identified and reviewed. Records of 11 patients who showed consecutive esotropia of 10 prism diopter (PD) or more with normal retinal correspondence, with or without diplopia complaint, after 6 week of surgery and had undergone vision therapy management were reviewed. A successful outcome of binocular single vision with good sensory and motor fusion with no manifest deviation or prism requirement was achieved with in the mean duration of 4.8 month of therapy. With a mean duration of 4 weeks of therapy, the mean angle of deviation reduced by 53% for distance (17 PD to 8 PD) and 27% for near (11 PD to 8 PD) and mean stereopsis improvement by 80% with 94% patients demonstrating sensory fusion on Bagolini test and 94% of patients having no symptoms of diplopia or squint. Conclusion: With nonsurgical management involving refractive error correction, FVT, and prism, consecutive esotropia was resolved in 74% cases. Management of consecutive esotropia with FVT can result in satisfactory sensory fusion and successful motor alignment.

Research progress on the risk factors and treatment of consecutive esotropia after exotropia surgeries / 上海交通大学学报（医学版）

Consecutive strabismus refers to the secondary manifest strabismus right after or a period after strabismus surgeries, including consecutive esotropia and consecutive exotropia. It is reported that the incidence of consecutive esotropia is 6%-20%. Consecutive esotropia may lead to increased risks of amblyopia and visual deficiency in children and diplopia in adults. As the multiformity and complexity of continuous esotropia, there exist many challenges for clinicians to know the risk factors well and select appropriate treatment. The article reviews the latest research progress on the risk factors and treatment strategies of consecutive esotropia, aiming to help better evaluate the risks of continuous esotropia after exotropia surgeries, adjust the operation plans, and provide references to select the appropriate treatment plan.

Consecutive cyclic esotropia � A case report

Cyclic esotropia, a rare condition of obscure etiology characterized by regularly alternating periods of esotropia and orthophoria. We present a case of a 7-year-old boy who underwent surgical correction for intermittent exotropia elsewhere and developed esotropia with cyclic pattern post-operatively. Initially the cycle was of half-day orthophoria and half-day esotropia, which later became one full day of esotropia and one day of orthophoria. During re-surgery, right lateral rectus was found to have a stretched scar which was resected and then advanced and medial rectus was recessed. Post-surgery the child was orthophoric without cyclic pattern.

Decision for Proper Surgical Amount in Consecutive Esotropia Following Bilateral Lateral Rectus Recession

PURPOSE: To determine the amount of additional surgery required for patients with consecutive esotropia, who had an esodeviation angle similar to their pre-operative exodeviation angle, following bilateral lateral rectus recession surgery for intermittent exotropia. METHODS: The medical records of 29 patients who underwent surgery for intermittent exotropia from 1998 through 2013 were reviewed. These patients had consecutive esotropia with an unchanged postoperative esodeviation angle. Thirteen patients underwent esotropia surgery with the aim of full correction (Group A), while 16 patients underwent esotropia surgery with the aim of partial correction (Group B). The postoperative ocular alignment and stereopsis of both groups were compared. RESULTS: A total of 29 patients were evaluated including 13 patients in Group A and 16 patients in Group B. At the final follow-up visit, at least 24 months post procedure, Group B had a significantly greater success rate than Group A (62.5% vs. 23.1%, p = 0.039). Over-correction rates were higher in Group A than Group B (76.9% vs. 37.5%, p = 0.039). The changes during the follow-up period (6 months to their last follow-up) showed that the over-correction rate had increased from 30.8% to 76.9% in Group A (p = 0.034) and from 12.5% to 37.5% in Group B (p = 0.046). CONCLUSIONS: Consecutive esotropia surgery with the aim of partial correction showed favorable motor and sensory outcomes in patients who had a postoperative esodeviation angle similar to that of their pre-operative exodeviation. This strategy may also be helpful in preventing long-term postoperative over-correction in patients presenting with consecutive esotropia.

Clinical Course of Consecutive Esotropia after Surgery to Correct Recurrent Intermittent Exotropia

PURPOSE: To analyze the clinical aspects of consecutive esotropia after intermittent exotropia reoperation and study the prognosis and associated risk factors. METHODS: The present study included 34 patients with intermittent exotropia who underwent reoperation; incidence rate, risk factors, treatment methods and prognosis of the postoperative consecutive esotropia were analyzed. RESULTS: Of the 34 patients, 12 developed consecutive esotropia that persisted longer than a month after the reoperation; a higher incidence rate was observed in patients with esodeviation greater than 16 prism diopter (PD) on postoperative day 1 and in patients who received unilateral lateral muscle recession and medial muscle resection during the operation (p < 0.05). Conversely, factors such as age, deviation angle, refractive power, anisometropia, lateral incomitance and oblique muscle dysfunction prior to the reoperation did not affect the incidence of consecutive esotropia. The patients who developed consecutive esotropia received conservative treatments such as alternative occlusion therapy and fresnel prism wearing; 10 of 12 patients showed significant clinical improvements. CONCLUSIONS: Consecutive esotropia frequently occurs after intermittent exotropia reoperation if the patient had esodeviation greater than 16 PD on postoperative day 1 or received unilateral lateral muscle recession and medial muscle resection. The conservative treatments of the consecutive esotropia showed good clinical response and improved prognosis.

Unilateral Lateral Rectus Muscle Advancement Surgery Based on One-fourth of the Angle of Consecutive Esotropia

PURPOSE: To evaluate the efficacy of unilateral lateral rectus muscle advancement surgery based on one-fourth of the angle of consecutive esotropia within 25 prism diopters (PD) which occurred after bilateral lateral rectus muscle recession for intermittent exotropia. METHODS: Medical records of 11 patients who underwent unilateral lateral rectus muscle advancement for consecutive esotropia from 2011 to 2014 and who were observed for at least 6 months after surgery were retrospectively reviewed. The change in the angle of deviation before and after consecutive esotropia surgery, success rate, and surgical effect were evaluated. RESULTS: Preoperative esodeviation was -19.6 ± 4.7 PD at distance and -16.5 ± 7.4 PD at near. Unilateral lateral rectus muscle advancement surgeries were performed based on one-fourth of the angle of consecutive esotropia and the mean surgical amount was 4.8 ± 1.1 mm. Of the total 11 patients, 10 patients (91%) recovered to orthotropia or exodeviation within 8 PD. One patient had a recurrence of esotropia at postoperative 3 months, but the patient recovered to orthotropia at postoperative 12 months with alternative patch treatment and a prism glass prescription. The surgical effect of unilateral lateral rectus muscle advancement was 3.3 ± 0.7 PD/mm at postoperative 1 day, 3.7 ± 0.6 PD/mm at postoperative 1 week, and 3.8 ± 0.7 PD/mm at postoperative 6 months. CONCLUSIONS: Unilateral lateral rectus muscle advancement surgery based on one-fourth of the angle of consecutive esotropia within 25 PD was successful in all 11 cases. The surgical effect was significantly greater in unilateral lateral rectus muscle advancement than in primary lateral rectus muscle recession. Thus, reduction in the amount of surgery should be considered carefully in unilateral lateral rectus muscle advancement for consecutive esotropia.

The Minimal Postoperative Follow-Up Period to Determine Secondary Surgery in Patients with Intermittent Exotropia

PURPOSE: We investigated the recommended minimum postoperative follow-up period for the determination of secondary corrective surgery for the consecutive esotropia (ET) and recurrent exotropia (XT) after the first intermittent XT surgery. METHODS: The medical records of 728 patients who underwent surgical treatment for intermittent XT between 2004 and 2009 with a minimum postoperative follow-up of 1 year were retrospectively reviewed. Each patient underwent a detailed sensory and motor examination, including measurements of near and distance stereoacuity, alternating-cover test, and extraocular muscle function testing. Consecutive ET was defined as esodeviation over 15 prism diopter (PD) at distance persisting for more than 6 months after surgery despite medical treatment. Recurrent XT was defined as exodeviation over 15 PD at distance after surgery despite medical treatment. RESULTS: The mean age of the 728 patients at first surgery was 7.5 years (range, 22 months - 30 years). When only the motor outcome was considered, 663 patients (91.1%) had an orthrotropia at the final follow-up and 44 patients (6.0%) among consecutive ET patients and 21 patients (2.9%) who had a recurrent XT underwent secondary surgical correction. Binocularity decreased postoperatively in patients with consecutive ET (p < 0.001), whereas the other patients demonstrated improved stereopsis postoperatively (p = 0.041, 0.021). Patients with consecutive ET showed esodeviation over 10 PD when compared with orthotropia after 2 months postoperatively (p = 0.005). At 6 months postoperatively, 17 (81.0%) of 21 patients with recurrent XT showed orthotropia with an exodeviation over 11 PD after 18 months postoperatively. CONCLUSIONS: The success rate of surgical correction for intermittent XT showed a favorable outcome. However, careful concern for consecutive ET and recurrent XT are required in postoperative follow-up periods. Over-corrected or consecutive ETs need early surgical correction because no further improvement of ocular alignment will occur after 2 months postoperatively and delayed correction can result in poor sensory binocularity. Under-corrected or recurrent XT should be observed for an extended period because of the exotropic drift after surgery, thus requiring periodic long term follow-up for secondary surgery at least for 18 months postoperatively.

The Minimal Postoperative Follow-Up Period to Determine Secondary Surgery in Patients with Intermittent Exotropia

PURPOSE: We investigated the recommended minimum postoperative follow-up period for the determination of secondary corrective surgery for the consecutive esotropia (ET) and recurrent exotropia (XT) after the first intermittent XT surgery. METHODS: The medical records of 728 patients who underwent surgical treatment for intermittent XT between 2004 and 2009 with a minimum postoperative follow-up of 1 year were retrospectively reviewed. Each patient underwent a detailed sensory and motor examination, including measurements of near and distance stereoacuity, alternating-cover test, and extraocular muscle function testing. Consecutive ET was defined as esodeviation over 15 prism diopter (PD) at distance persisting for more than 6 months after surgery despite medical treatment. Recurrent XT was defined as exodeviation over 15 PD at distance after surgery despite medical treatment. RESULTS: The mean age of the 728 patients at first surgery was 7.5 years (range, 22 months - 30 years). When only the motor outcome was considered, 663 patients (91.1%) had an orthrotropia at the final follow-up and 44 patients (6.0%) among consecutive ET patients and 21 patients (2.9%) who had a recurrent XT underwent secondary surgical correction. Binocularity decreased postoperatively in patients with consecutive ET (p < 0.001), whereas the other patients demonstrated improved stereopsis postoperatively (p = 0.041, 0.021). Patients with consecutive ET showed esodeviation over 10 PD when compared with orthotropia after 2 months postoperatively (p = 0.005). At 6 months postoperatively, 17 (81.0%) of 21 patients with recurrent XT showed orthotropia with an exodeviation over 11 PD after 18 months postoperatively. CONCLUSIONS: The success rate of surgical correction for intermittent XT showed a favorable outcome. However, careful concern for consecutive ET and recurrent XT are required in postoperative follow-up periods. Over-corrected or consecutive ETs need early surgical correction because no further improvement of ocular alignment will occur after 2 months postoperatively and delayed correction can result in poor sensory binocularity. Under-corrected or recurrent XT should be observed for an extended period because of the exotropic drift after surgery, thus requiring periodic long term follow-up for secondary surgery at least for 18 months postoperatively.

The Long-Term Outcome of Lateral Rectus Advancement in Patients with Consecutive Esotropia Following Bilateral Lateral Rectus Recession for Intermittent Exotropia

PURPOSE: To investigate the long-term outcome of lateral rectus (LR) advancement for consecutive esotropia following bilateral LR recession for intermittent exotropia. METHODS: Medical records of 25 patients who underwent LR advancement for consecutive esotropia after bilateral LR recession and who were followed up for more than 24 months postoperatively were reviewed. Patients were divided into two groups: bilateral lateral rectus recession (BLR) group included 16 patients with consecutive esotropia greater than or the same magnitude as the initial exotropia and who underwent bilateral LR advancement; Unilateral lateral rectus recession (ULR) group included nine patients with consecutive esotropia less than the initial exotropia and who underwent unilateral LR advancement. Main outcome measurements were motor and sensory outcomes and the dose-effect relationship calculated from observed overall and group changes in the angle of deviation per millimeter. Motor success was defined as alignment from orthotropia to exodeviation less than 10 PD at distance. Sensory outcome was described by comparing the Titmus stereoacuity test before and after LR advancement. Sensory successvwas defined at 100 seconds of arc. RESULTS: Eighteen patients (72.0%) showed satisfactory long-term motor and sensory outcomes. Seventeen (77.3%) of 22 patients showed favorable stereopsis of 100 seconds of arc or more at final observation. The long-term motor success rate of the ULR group was better than that of the BLR group (p = 0.025). The average observed change in the angle of deviation was 3.6 PD/mm at the final visit in all patients. A greater dose-effect relationship was observed in the ULR group than in the BLR group at the final visit (p = 0.043). CONCLUSIONS: LR advancement showed favorable motor and sensory outcomes in the majority of patients. The surgical outcome was not favorable in patients in the BLR group with consecutive esotropia of the same magnitude as the initial exotropia. These results require further investigation for verification.

Clinical Manifestation after Surgical Correction of Consecutive Esotropia

PURPOSE: To report the clinical outcome of patients with consecutive esotropia (ET) in the pre- and post-operative periods and at the last postoperative visit. METHODS: The present study included 12 patients who underwent surgery for the correction of consecutive ET. The angle of deviation, duration of consecutive ET, and surgical and non-surgical methods for correction of consecutive ET were investigated. The sensory status was evaluated before the surgery of exotropia (XT), during consecutive ET and after the surgery for consecutive ET. RESULTS: The average angle of deviation before the surgery of XT was 27.5 PD and 3 patients had lateral incomittancy. Alternate occlusion treatment was performed in all patients, and 10 patients wore Fresnel prisms. The average angle of deviation of consecutive ET was 24.3 PD. After an average of 30 months postoperative consecutive ET, 9 patients were orthotropic or had deviation within 8 PD, 2 patients had 15 PD ET, and 1 patient had 20 PD XT. There were 3 patients whose stereopsis was aggravated and 1 patient had poorer fusion during consecutive ET, and recovered after the surgery for consecutive ET. No patients had a decrease in visual acuity. CONCLUSIONS: As a result of alternate occlusion and Fresnel prisms during consecutive ET after surgery of XT, the incidence of aggravation in binocularity was low, and the cases with aggravated binocularity were recovered after surgical correction of consecutive ET. The surgical success rate was 75% in consecutive ET.

Consecutive Esotropia after Lateral Rectus Muscle Recession for Intermittent Exotropia

PURPOSE: To evaluate the progress and outcome of consecutive esotropia after surgery for intermittent exotropia. METHODS: The authors investigated the risk factors, changes in the angle of esodeviation and treatment outcome in consecutive esotropia after lateral rectus muscle recession for intermittent exotropia in 196 patients. RESULTS: Consecutive esotropia occurred in 25 patients (12.8%). The patients underwent more frequent combined muscle surgeries on vertical and oblique muscles (p = 0.001) and had a greater amount of immediate postoperative overcorrection than subjects without consecutive esotropia. There was no significant difference with the incidence of overcorrection greater than 17 PD between the 2 groups with and without consecutive esotropia. There was no difference with the immediate postoperative overcorrection between the 6 cases that required surgery for their consecutive esotropia and the cases that recovered from their consecutive esotropia with conservative treatment. The former showed increasing esodeviation and maximum angle at average postoperative month 29.5. In the latter, esodeviation tended to decrease and showed maximum angle at average postoperative month 4.3. Finally, esotropia disappeared and good stereoacuity was obtained in both cases. CONCLUSIONS: Although subjects with consecutive esotropia had a greater immediate postoperative overcorrection than subjects without consecutive esotropia, the progress and outcome of consecutive esotropia following the initial overcorrection were not predictable. Consecutive esotropia after surgery for intermittent exotropia showed good overall outcome and well-preserved stereoacuity after treatment.

Secondary Superior Oblique Overaction after Inferior Oblique Muscle Myectomy in a Patient Misdiagnosed with Inferior Oblique Muscle Overaction

PURPOSE: To report a case of superior oblique muscle tenotomy in a patient with suspected bilateral inferior oblique muscle overaction. The patient showed secondary superior oblique muscle overaction and inferior oblique muscle underaction after inferior oblique muscle myectomy. CASE SUMMARY: The patient showed V-pattern exotropia with suspected bilateral inferior oblique muscle overaction. After bilateral lateral rectus muscle recession with bilateral inferior oblique muscle myectomy, the patient showed secondary esotropia and inferior oblique underaction. After the surgery, progressive secondary superior oblique muscle overaction continued and finally, a superior oblique muscle tenotomy was performed. After the superior oblique muscle tenotomy, the superior oblique muscle overaction was corrected but the inferior oblique muscle underaction continued. CONCLUSIONS: After an inferior oblique muscle myectomy, secondary superior oblique muscle overaction can develop. Thus, caution should be taken in diagnosing inferior oblique muscle overaction in patients who show minimally inferior oblique muscle overaction as well as the surgical methods chosen.

Curso clínico de una endotropía consecutiva una cirugía de estrabismo. Reporte de un caso / Clinical course of a consecutive esotropia from an strabismus surgery. Case Report

Propósito: analizar y describir el curso clínico de una exotropía recurrente, que luego de la re operación presenta un endotropía consecutiva. Métodos: paciente femenina de 4 años 5 meses, con diagnóstico de exotropía intermitente. Se le realizó retroinserción derechos laterales a 6,5 mm en ambos ojos. La exotropía recurrió en un año. Posteriormente se le realizó resección de rectos medios de 6 mm. El resultado posoperatorio fue una endotropía consecutiva de involución espontánea. Resultados: al realizar la primera cirugía para exotropía, se obtuvo un resultado de micro endotropía que evolucionó a exotropía recurrente. En la re operación se obtuvo una endotropía consecutiva de 20 dioptrías prismáticas que actualmente está en involución. Conclusión: Debe considerarse una hipercorrección inicial en la cirugía de exotropía. En el caso de una segunda operación para exotropía recurrente, se debe tener en cuenta que ésta puede volvera recurrir, aun cuando la tasa de recurrencia es menorque en la primera cirugía, y una nueva hipercorrección puede también ser recomendable. La endodesviación pos tiende a disminuir y dejar de persistir a los seis meses posoperatorios.

Purpose: to analyze and describe the clinical course of a recurrent exotropia, which after re-surgery developed a consecutive esotropia. Methods: female subject, 4 year and 5 months old, with an intermittent exotropia diagnosis. A retro insertion of the lateral rectus to 6,5 mm in both eyes was performed. Exotropia reappeared in one year. Subsequently, a 6 mm resection of both middle rectus was performed. The postoperatory result was a self involutive consecutive esotropia. Results: after first surgery for exotropia, a micro esotropia was obtained and it evolved to recurrent exotropia. In the new surgery a 20 prismatic diopters consecutive esotropia was obtained and it is currently involutioning. Conclusion: an hypercorrection should be considered in the procedure. In the case of a second surgery for recurrent exotropia, it should be considered that exotropia could reappear, although in a less recurrence rate that in the first one, so another hypercorrection should be considered too. Postoperative esodeviation after exotropia surgery tends to diminish and stop persisting after six months.

Clinical Course of Patients with Consecutive Esotropia Angle Larger Than Preoperative Angle After Exotropia Surgery

PURPOSE: To report the clinical course of severe consecutive esotropia (ET) with an esotropic angle at postoperative day 1 larger than the preoperative exotropia angle (XT). METHODS: Patients with ET angles at postoperative 1 day greater than their preoperative XT angles were included; the case of lost lateral rectus during surgery was excluded. Preoperative clinical characteristics and the course of postoperative alignment were analyzed, and binocularity was compared between the preoperative state and the postoperative state. RESULTS: The mean preoperative angle of XT of 13 patients was 23 prism diopters (PD) at distance and 27PD at near. Lateral incomitancy was observed in 9 patients. One day postoperatively, the mean angle of ET was 27PD at distance and 25PD at near, and alternate occlusion therapy was performed in all patients. However, the angle of ET was decreased 10PD or less in only 3 patients. All 13 patients were managed with Fresnel prisms, and 4 patients had orthotropia. Another 4 patients used glass prisms because they had ET of 8PD or less, and the remaining 5 patients still showed an ET with 12PD or more. Binocularity after surgery was worse than that before surgery in 64% of patients. CONCLUSIONS: For patients with ET angles at postoperative 1 day greater than preoperative XT angles, the frequency of lateral incomitancy was high. Alternate occlusion and Fresnel prism treatment were needed in all patients. Recovery from orthotropia and the prognosis of binocularity were relatively poor.

Consecutive Esodeviation After Exotropia Surgery in Patients Older than 15 Years: Comparison with Younger Patients

PURPOSE: The purpose of this study was to investigate the clinical course of esodeviation after exotropia surgery in older patients (older than 15 years) and to compare it with that in younger patients (15 years or younger). METHODS: The medical records of all surgeries for exodeviation from December 2004 to February 2007 were reviewed and 82 patients were found with consecutive esodeviation. The patients were divided into two groups according to their age: Group A (patients older than 15 years) and Group B (patients age 15 or younger). The clinical course of esodeviation in Group A was compared to that in Group B by means of survival analysis. RESULTS: The median survival times of the esodeviation were 2.0+/-0.1 months in Group A and 1.0+/-0.1 months in Group B (p=0.40). The prevalence of consecutive esotropia at six months was 0% in Group A and 6.1% in Group B (p=0.32). The myopic refractive error, worse sensory condition, and a larger preoperative exodeviation in Group A did not affect the clinical course of the two groups differently. CONCLUSIONS: The postoperative esodeviation of patients older than 15 years after exotropia surgery tended to persist longer during the early postoperative period than that of patients 15 years or younger, however, the difference did not persist at postoperative six months.

The Effect of Lateral Rectus Muscle Advancement in Consecutive Esotropia After Bilateral Rectus Muscle Recession

PURPOSE: To investigate the clinical outcomes of unilateral lateral rectus muscle advancement in patients with consecutive esotropia after bilateral lateral rectus muscle recession. METHODS: We investigated the results of 13 patients who underwent unilateral lateral rectus muscle advancement for consecutive esotropia after bilateral lateral rectus muscle recession. We evaluated the amount of deviation, changes of angle deviation, corrected amount/mm, and sensory status after each surgery. RESULTS: The average angle deviation of exotropia was 30.42+/-5.41PD, and the average amount of bilateral lateral rectus muscle recession was 6.73+/-0.59 mm. The average angle deviation of esotropia one day after the surgery was 13.17+/-5.15PD. Occlusion treatment was performed during follow-up. The surgery for consecutive esotropia was performed after an average of 12.0+/-7.25 months of follow-up. In Worth-4-dot tests, 12 patients showed diplopia, and 1 patient showed suppression after the surgery for exotropia. Nine patients showed diplopia, and 4 patients showed suppression just before the surgery for consecutive esotropia. One patient showed mild limitation of motion of the lateral rectus muscle (-1 degree). The average angle deviation before the surgery for consecutive esotropia was 19.42+/-4.20PD. An average of 6.73+/-0.79 mm of unilateral lateral rectus muscle advancement was performed. After surgery, the average angle deviation was 1.25+/-2.73PD esodeviation, and 1.42+/-4.44PD exodeviation after 6 months. In Worth-4-dot tests, 6 patients showed fusion, 2 patients showed diplopia, and 5 patients showed suppression after surgery for consecutive esotropia. CONCLUSIONS: Unilateral lateral rectus muscle advancement was an effective procedure for patients with consecutive esotropia under 25PD who did not show any limitation of motion after bilateral lateral rectus recession.

Clinical Course of Patients With Delayed Consecutive Esotropia After Exotropia Surgery

PURPOSE: To report the characteristics and therapeutic results of patients with delayed consecutive esotropia after undergoing surgery for exotropia. METHODS: Ten patients with delayed consecutive esotropia of more than 10 prism diopters (PD) after orthotropia was obtained postoperatively were included in this study. The authors investigated the clinical characteristics, the deviated angle at postoperative day one, the duration between surgery and orthotropia, the duration between surgery and delayed esotropia, the angle of esotropia, and the result of treatment in delayed consecutive esotropia. RESULTS: The average of the preoperative angle of exodeviation was 30PD at distance and 31PD at near. The patients underwent surgery for exotropia at a mean age of 5.3 years, and one day postoperatively, the angle of esodeviation was 12PD at distance and 10PD at near. All 10 patients demonstrated orthotropia at 0.9 months after surgery. However, esotropia of 21PD occurred 4 months after surgery for all patients. Six of the 10 patients demonstrated orthotropia or 10PD or less at the last visit after patching therapy or fitting for Fresnel prism glasses. The remaining four patients did not improve or showed aggravated esotropia with a doubled-angle of esotropia. CONCLUSIONS: In patients with orthotropia after exotropia surgery, delayed consecutive esotropia can occur, and the prognosis of non-surgical treatment is relatively poor.

Consecutive Esotropia in Intermittent Exotropia Patients with Immediate Postoperative Overcorrection More Than 17 Prism Diopters

PURPOSE: To report the incidence and the factors of consecutive esotropia (ET) in patients with immediate postoperative overcorrection of at least 17 prism diopters (PD) after surgery for intermittent exotropia (X(T)). METHODS: Four-hundred-five patients under the age of 18 were included in this study. They underwent bilateral lateral rectus recession (LROU-rec) or unilateral recession-resection (R&R) for X(T). On postoperative day one, the patients with at least 17 PD overcorrection were classified as group 1 and those with less than 17 PD as group 2. Age, refractive error, type of surgery, lateral incomitancy, and the incidence of consecutive ET were analyzed for each group. RESULTS: Group 1 consisted of 116 patients (28.6%) and group 2 consisted of 289 (71.4%). At the six-month follow-up visit, consecutive ET had developed in 16 patients (13.8%) in group 1, and in five patients (1.7%) in group 2 (p<0.001). The occurrence of consecutive ET was not related to age at the time of surgery (p=0.46 in group 1 ; p=0.54 in group 2), refractive error (p=0.18 in group 1 ; p=0.08 in group 2), or the type of surgery (p=0.69 in group 1 ; p=1.00 in group 2). The incidence in group 1 was 23.8% in patients with lateral incomitancy and 8.1% in patients without lateral incomitancy (p<0.05). In group 2, the incidence was 4.4% in patients with lateral incomitancy and 0.5% in patients without lateral incomitancy (p=0.04). CONCLUSIONS: Consecutive ET developed in 13.8% of patients with immediate overcorrection of at least 17 PD. Lateral incomitancy was the most important risk factor.

The Clinical Course of Consecutive Esotropia after Surgical Correction

PURPOSE: To investigate the clinical course in patients who underwent surgical correction of consecutive esotropia. METHODS: The medical records of 13 patients who underwent surgical correction of consecutive esotropia were reviewed retrospectively. The authors investigated the deviation and surgical method at the time of exotropia surgery. During the follow up period, the authors also studied incidence of amblyopia development, the effect of occlusion therapy, surgical methods for consecutive esotropia, and postoperative change of deviation. RESULTS: The average exodeviation was 27.1 prism diopter (PD). Bilateral lateral rectus muscle recession was performed in all patients. In all patients, alternate occlusion was tried from 2 weeks after development of consecutive esotropia. However, there was no effect on 7 patients. None of the patients developed amblyopia. Surgery for consecutive esotropia was performed on the average 15.3 months after exotropia surgery. The average esodeviation was 21.1PD. Medial rectus muscle recession was performed in 10 patients and lateral rectus muscle advancement in 3 patients. The average deviation of the subject group immediately after surgery was 1.2PD esodeviation, 0.9PD esodeviation one month after surgery, 2.4PD exodeviation 6 months after surgery, and 4.7PD exodeviation at the last follow up, and it showed a tendency to progress to exodeviation as the follow up period increased. Ten patients (76.9%) showed deviation within 8PD at the last follow up. CONCLUSIONS: The success rate of surgical correction for consecutive esotropia was a favorable outcome. But, careful decisions of the surgical method and amount is needed because the conversion of exodeviation during long-term follow-up is possible.

The Effect of Fresnel Prism Treatment in Consecutive Esotropia

PURPOSES: To investigate the effect of Fresnel prism treatment in patients with consecutive esotropia after the surgery of exotropia. METHODS: Eighteen patients who have failed alternating occlusion therapy at least 1 month for consecutive esotropia without limitation of ocular motility following surgery for an exotropia were managed with Fresnel prism for esotropia associated with diplopia. The Fresnel prismatic power was selected to solve the diplopia and was changed in accordance with the degree of esodeviation during the follow up period. The surgical correction was performed in the case with increase of esodeviation in spite of the Fresnel prism therapy for 6 months or more. The angle of deviation and diplopia before and after the Fresnel prism therapy were investigated. RESULTS: The mean age at surgery for an exotropia was 7.8 years. The Fresnel prism therapy was performed at 4.2 months after exotropia surgery to solve esotropia in average 15.4 prism diopters (PD) at distance and 14.8PD at near. Of the 18 patients 11 (61.1%) had a successful outcome after average 14.8 months, i.e. 8PD or less of esodeviation, with relief of diplopia without the Fresnel prism. Two patients used the Fresnel prism to solve diplopia associated with esodeviation of 8PD or less. Five patients had esodeviation with 10PD or more and 2 of them were eventually needed a operation for esotropia. CONCLUSIONS: The Fresnel prism treatment is an effective device in treating diplopia as well as decreasing the frequency of surgery for esotropia in consecutive esotropia with diplopia.