Quantitative grading evaluation of the therapeutic efficacy of asymmetric bilateral lateral rectus recession in type Ⅲ Duane retraction syndrome / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To quantitatively evaluate the therapeutic efficacy of the asymmetric recession of bilateral lateral rectus in patients with unilateral type III Duane retraction syndrome.METHOD:Retrospective analysis of clinical data. The clinical data of 12 cases of type III Duane retraction syndrome with unilateral lateral rectus recession were analyzed. All subjects had restricted internal rotation, with narrowing of the palpebral fissure and vertical deviation, and restricted external rotation with widening of the palpebral fissure. All patients had abnormal head positions. The degree of strabismus was measured while maintaining the head in a neutral position. Asymmetric recession of bilateral lateral rectus was selected based on the degree of strabismus of affected eye or 1～3mm longer, with a smaller recession and Y-splitting in the affected eye and a larger recession in the healthy eye.RESULT:The difference in the degree of strabismus in the healthy eyes before and after surgery was statistically significant(Z=-4.158, P<0.01), as was the difference in the degree of restricted internal rotation(Z=-2.640, P=0.008). The difference in the degree of restricted external rotation was not statistically significant(Z=-1.732, P=0.083). The difference in abnormal head position was statistically significant(Z=-4.181, P<0.01), while the difference in eyeball recession was not statistically significant(Z=-1.414, P=0.157). The difference in vertical deviation was statistically significant(Z=-3.115, P=0.002). A total of 10 patients(83%)had stereoscopic vision before surgery, and 11 patients(92%)had recovered stereoscopic vision after surgery, with a further improvement in stereoacuity in 50% of patients.CONCLUSION:Asymmetric recession of bilateral lateral rectus combined with Y-splitting of the affected lateral rectus can effectively improve the degree of strabismus, abnormal head position, vertical deviation and stereoacuity without aggravating the degree of restriction of external rotation or eyeball recession.

Curative effect of slanted bilateral lateral rectus recession for convergence insufficiency-type intermittent exotropia / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To observe curative effect and safety of slanted bilateral lateral rectus recession for convergence insufficiency-type intermittent exotropia.<p>METHODS:This study included 29 patients who underwent slanted bilateral lateral rectus recession for convergence insufficiency-type intermittent exotropia in our hospital between October 2017 and November 2019 with a follow-up of 6mo, the deviation, the surgical success rate, the binocular vision function and the complications were observed.<p>RESULTS:In our study, the mean near deviations, the mean distance deviations and the near-distance deviation differences reduced from -41.72±3.35PD, -23.28±9.75PD and 16.90±2.47PD before surgery to -5.97±4.85PD, -2.66±4.78PD, 3.28±1.10PD 6mo after surgery, the surgical success rate was 76%. The Grades I and Ⅱ binocular vision function improved 6mo after surgery(<i>P</i><0.05), the distance stereopsis and the near stereopsis were not statistically significant(<i>P</i>>0.05). None of the patients developed A-V pattern, limitation of eye movement, restrictive strabismus, vertical strabismus, and rotated diplopia, some patients had transient horizontal diplopia, which disappeared within 2-3wk after surgery.<p>CONCLUSION:Slanted bilateral lateral rectus recession may successfully reduce the near exodeviations, the distance exodeviations and the near-distance deviations difference without obvious complications, proved to be a safe and effective procedure for the treatment of convergence insufficiency-type intermittent exotropia.

Long-term Results of Slanted Recession of Bilateral Lateral Rectus Muscle for Intermittent Exotropia with Convergence Insufficiency

PURPOSE: To evaluate the long-term efficacy of slanted lateral rectus recession in children for reducing distance and near exodeviation and near-distance deviation difference in intermittent exotropia with convergence insufficiency. METHODS: The medical records of 53 patients with convergence insufficiency intermittent exotropia who underwent slanted bilateral lateral rectus recession performed by a single surgeon and received follow-up for more than 12 months were retrospectively analyzed. Deviation angles at 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively and on the last visit were reviewed. Surgical success was defined as postoperative residual distance and near deviation angles ≤8 prism diopters and a difference between the near and distance angles ≤8 prism diopters. RESULTS: The mean duration of follow-up was 24 months (range, 12 to 61 months). On the last visit, the residual deviation angles were ≤8 prism diopters in 75.5% for distance, 62.3% for near, and 81.1% for the near-distance difference. Surgical success was achieved in 31 (58.5%) patients, and none of them manifested limitations in eye movements or diplopia at the last follow-up visit. CONCLUSIONS: Slanted lateral rectus recession is an effective surgical method for reducing distance and near exodeviation and near-distance deviation difference in intermittent exotropia with convergence insufficiency.

Binocular lateral rectus recession versus monocular recess-resect procedure for basic intermittent exotropia:a Meta analysis of randomized controlled trials / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To compare the curative effect between monocular lateral rectus recession(BLR)and Binocular recession resection(R & R)for basic intermittent exotropia.<p>METHODS:A literature review using the MEDLINE, EMBASE, The Cochrane Library, Web of Science, Clinical Trial, CBM, Wanfang Databases and paper collections of conferences was performed. Randomized controlled trials comparing the effects of BLR and R & R for basic intermittent exotropia with a duration of follow-up at least half a year were eligible for inclusion. The methodologic quality of included studies was evaluated independently by 2 authors. Statistical analysis was performed by using the STATA 14 software(StataCorp Texas USA).<p>RESULTS:Five prospective random controlled clinical trials involving 529 patients were included. Compared with R & R procedure,the BLR procedure group showed lower successful rate(<i>RR</i>:0.85; 95% <i>CI</i>:0.72-0.99; <i>P</i>=0.043)and postoperative undercorrection(<i>RR</i>:3.975; 95% <i>CI</i>:2.097-7.537; <i>P</i><0.01). The <i>P</i> value of long-term postoperative corrected rate in Meta analysis was decreased near to 0.05 when the included references increased. There was no significant difference in overcorrection rate between the BLR and R & R procedures(<i>RR</i>:0.336; 95% <i>CI</i>:0.049-2.294; <i>P</i>=0.266).<p>CONCLUSION:Current evidences suggested that BLR procedure is related to lower successful and higher undercorrection rates for basic intermittent exotropia compared to conventional R & R procedure.

Comparison of Binocular Function and Surgical Outcomes of Tenacious Proximal Fusion and High Accommodative Convergence/Accommodation Ratio Types of Intermittent Exotropia

PURPOSE: To compare the characteristics and surgical outcomes in patients with tenacious proximal fusion (TPF) and high accommodative convergence/accommodation ratio (AC/A) types of intermittent exotropia. METHODS: This study retrospectively enrolled 40 patients with intermittent exotropia, 23 with TPF and 17 with high AC/A. Binocular function was evaluated by Worth's 4-dot test. Patients underwent lateral rectus recession, and surgical outcomes were compared. Surgical success was defined as less than ±10 prism diopters (PD) at 12 months postoperatively. RESULTS: The proportion of diplopia at near, evaluated by Worth's 4-dot test, was significantly higher in patients with high AC/A than in those with TPF (35.3% vs. 4.3%, p = 0.029). The mean preoperative angles of deviation in TPF and high AC/A types were 28.3 ± 4.4 and 28.8 ± 4.5 PD at distances, and 14.7 ± 4.2 and 15.1 ± 4.1 PD at near. Twelve months after surgery, the mean angles of deviation in TPF and high AC/A types were 2.9 ± 9.8 and 1.2 ± 9.6 PD, respectively, at distance and 1.7 ± 7.7 and −1.3 ± 11.3 PD at near. The surgical success rates were similar in the TPF and high AC/A types (74.0% vs. 64.7%). Five (21.7%) patients with TPF and 2 (11.8%) with high AC/A type experienced recurrence, with consecutive esotropia occurring in 1 (4.3%) patient with TPF and 4 (23.5%) patients with high AC/A. CONCLUSIONS: The proportion of diplopia at near was higher in patients with high AC/A type than in those with TPF intermittent exotropia. However, the surgical success rates were not significantly different between the types.

The Effect of Bilateral Medial Rectus Resection for Recurrent Intermittent Exotropia

PURPOSE: The purpose of this study was to investigate the effect of bilateral medial rectus muscle resection on the treatment of recurrent intermittent exotropia. METHODS: A retrospective chart analysis was conducted for 25 patients who underwent bilateral medial rectus resection for recurrent exotropia over 20 prism diopters (PD) between January 2009 and August 2015. The medial rectus was resected from 4.0 to 6.5 mm by 0.5 mm according to the deviation angle. The postoperative angle of deviation was checked at 1 day, 1 week, 3 months, 6 months, and 1 year postoperatively to investigate the amount of corrected deviation per resected muscle. RESULTS: The average preoperative deviation angle was 27.20 ± 5.02 PD exodeviation and the mean resection was 5.10 ± 0.79 mm of the medial rectus. The postoperative angle deviation was 10.68 ± 5.50 PD esodeviation at 1 day. The incidence of esodeviation tended to decrease over time. At 1 year, the postoperative angle deviation was 1.16 ± 7.54 PD esodeviation. The overcorrection rate was 84% at 1 day postoperatively but decreased to 24% at 1 year with a success rate of 68%. The corrected deviation angle per millimeter was 7.53 ± 1.22, 7.75 ± 2.16, 6.27 ± 1.74, 5.50 ± 1.54, and 5.56 ± 1.58 PD/mm at 1 day, 1 week, 3 months, 6 months, and 1 year after surgery, respectively. The dose effect per millimeter decreased over time. The corrected deviated angle per millimeter remained constant regardless of the amount of medial rectus muscle resection at 1 year postoperatively(p=0.939). CONCLUSIONS: Bilateral medial rectus resection for recurrent exotropia over 20 PD tended to overcorrect at first; however, after 1 year, the mean angle of deviation was 1.16 ± 7.54 PD esodeviation. Bilateral medial rectus resection is an effective surgical method for the treatment of recurrent exotropia over 20 PD.

Comparison between Modified Bilateral Lateral Rectus Recession and Augmented Unilateral Recession-resection for Convergence Insufficiency Exotropia

PURPOSE: To compare the surgical outcomes between modified bilateral lateral rectus muscle (BLR) recession and augmented unilateral recession-resection (R&R) for the convergence insufficiency intermittent exotropia (IXT). METHODS: 37 patients with convergence insufficiency IXT were divided into two groups: 13 patients (underwent BLR recession) and 24 patients (underwent unilateral R&R). Success was defined as within 10 prism diopters (PD) at distance and near, and within 10 PD of the difference between them at postoperative 12 months. RESULTS: After the patch test, the preoperative distance deviation angle in the BLR group was 29.9 ± 8.4 PD, and the near deviation angle was 42.3 ± 9.7 PD; the difference between them was 12.5 ± 3.2 PD. In the R&R group, the preoperative distance deviation angle was 26.7 ± 5.8 PD, and the near deviation angle was 41.5 ± 7.4 PD; the difference between them was 14.8 ± 4.3 PD (p = 0.235, p = 0.987, and p = 0.123). At the 12-month follow-up in the BLR group, the distance angle was 3.8 ± 5.1 PD, and the near deviation angle was 4.9 ± 6.1 PD; the difference between them was 2.9 ± 5.9 PD. In the R&R group, the postoperative distance deviation angle was 4.7 ± 6.1 PD, and the near deviation angle was 7.9 ± 6.6 PD; the difference between them was 3.65 ± 5.1 PD (p = 0.708, p = 0.162, and p = 0.632, respectively). The surgical success rate did not differ significantly between groups at 12 months postoperatively (76.9%: BLR group and 70.8%: R&R group; p = 0.690). CONCLUSIONS: Modified BLR recession showed a similar surgical success rate to augmented unilateral R&R, and was effective in reducing both distance and near exodeviation, and in decreasing the difference between distance and near deviation in convergence insufficiency IXT.

Retroceso bilateral de rectos laterales comparado con retroceso/resección unilateral para el tratamiento de la exotropia intermitente básica / Bilateral lateral rectus recession versus unilateral recession/resection for basic intermittent exotropia

Resumen INTRODUCCIÓN: En determinadas circunstancias clínicas, la exotropia intermitente básica requiere resolución quirúrgica. Existen dos técnicas para ello: el retroceso bilateral de rectos laterales y el retroceso/resección unilateral. Aunque el retroceso bilateral es la técnica más utilizada, no está claro cuál de estas técnicas tiene mejores resultados. MÉTODOS: Para responder esta pregunta utilizamos Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante búsquedas en múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, reanalizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. RESULTADOS Y CONCLUSIONES: Identificamos cinco revisiones sistemáticas que en conjunto incluyeron siete estudios primarios, de los cuales tres son ensayos aleatorizados. Concluimos que el retroceso/resección unilateral podría tener un mayor éxito quirúrgico y probablemente disminuiría la tasa de subcorrección/recurrencia, cuando se le compara al retroceso bilateral de rectos laterales.

Abstract INTRODUCTION: Intermittent exotropia requires surgical resolution under some clinical circumstances. The main techniques are bilateral lateral rectus recession and unilateral recess/resection. Although bilateral recession is the most widely used, it is not clear whether it leads to better results. METHODS: To answer this question we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS: We identified five systematic reviews including seven studies overall, of which three were randomized trials. We concluded unilateral recess/resection might achieve greater surgical success and probably decrease the rate of undercorrection/recurrence when compared to bilateral lateral rectus recession.

Observation on the curative effects of two surgical methods for basic intermittent exotropia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To explore the differences between unilateral recess-resection (R & R) and bilateral lateral rectus recession (BLR-rec) in the treatment of basic intermittent exotropia.METHODS: A retrospective analysis of treatment of basic intermittent exotropia in 89 patients,in which 49 cases underwent unilateral recess-resection,40 cases underwent bilateral lateral rectus recession of external rectus retroperitoneal surgery January 2013 to January 2015 in our hospital.The stereopsis and strabismus were observed in 1d,1,6mo,1 and 2a after operation.RESULTS: There was no significant difference in the success rate and oblique degree between the two groups after 1d,1,6mo,1 and 2a (all P>0.05),but the success rate of the operation was reducing as time passed.After 2d of the operation,the drift of the R & R group was 12.10±5.74PD and the drift of the BLR-rec group was 7.78±4.21PD,the difference was statistically significant (P=0.021).The R & R group was more likely to cause lateral slanting than BLR-rec group.Two groups of patients with nearly stereopsis were both significantly improved,there was no significant difference between the two groups in the two groups (x2=4.530,P=0.210).CONCLUSION: The long-term stability of BLR-rec is superior to R & R.

Therapeutic evaluation of lateral rectus super-recession surgery for large angle divergence excess exotropia / 中华实验眼科杂志

Background In clinic practice,three or four rectus muscles often are needed to perform operation for the correction of large angle (＞50Δ) exotropia to avoid eye limited abduction due to lateral rectus superrecession.However,recent study reported that lateral rectus super-recession surgery can effectively correct large angle exotropia without remarkable abduction limitation.This outcome still need to be verified in clinical practice.Objective This study was to observe the outcome of bilateral rectus super-recession or medial rectus resection of the combined non-dominant eye for large angle exotropia.Methods A series case study was carried out.Fifty-one patients with intermittent or constant exotropia were enrolled in Tianjin Eye Hospital from May 2013 to October 2014.There were 29 intermittent exotropia and 22 constant exotropia among the 51 patients.Combined with adjustable sutures,bilateral lateral rectus super-recession or medial rectus resection of combined non-dominant eye was performed in all the eyes,and the examination of the anterior segment,fundus,ocular movement and binocular vision were performed before and after surgery.The deviation angle was measured by prism and alternate cover test.The individualized surgery procedure was designed according to medical history,ocular movement,sensory status and deviation angle.The patients were followed-up for at least 6 months.The eye position,ocular movement and binocular sensory function were compared between peoperation and postoperation.This study was approved by the Ethics Committee of Tianjin Eye Hospital.Written informed consents before the operation were obtained from all patient or their parents.Results Thirty-three patients underwent bilateral lateral super-recession and 18 patients underwent bilateral lateral super-recession of the medial rectus resection of the combined non-dominant eye.The mean angle of exotropia for seeing distance of 5 meters was (-70.57 ± 16.46) Δ (from-52 Δ to-120 Δ) and was (-75.65 ±16.14) Δ for seeing near (33 cm) (from-55Δ to-130Δ).The mean amount of left eye recession was 8-15 mm ([11.17±1.67] mm) and the right eye recession was 9-15 mm ([11.28±1.62] mm).The medial rectus of the dominant eye was resected by 3-6 mm.At the end of following-up,the mean angle of exotropia for seeing distance was (-3.45±4.20) Δ (from +4Δ to-14Δ) and was (-5.49±3.96) Δ for seeing near (from +4Δ to-14Δ).Surgical outcome was effective in 41 patients (80.4％),and 10 patients were undercorrected.The stereopsis of 32 patients improved after surgery,and 18 of 27 patients without preoperative stereopsis function obtained stereopsis after surgery.No ocular motility disorder was found in this group of patients after surgery.Conclusions Bilateral lateral rectus super-recesssion or medial rectus resection of combined non-dominant eye can effectively correct large angle exotropia and reduce the number and amount of surgical muscles without ocular motility disorder.

Postoperative Exodrift Patterns after Bilateral or Unilateral Lateral Rectus Recession in 20 Prism-diopter Intermittent Exotropia

PURPOSE: In the present study, the surgical outcome and postoperative exodrift pattern between bilateral lateral rectus recession (BLR) and unilateral lateral rectus recession (ULR) in intermittent exotropia of 20 prism diopters (PDs) were compared. METHODS: In this retrospective study, 5.0 mm BLR or 8.5 mm ULR was performed on 82 patients for the treatment of intermittent exotropia of 20 PDs with a follow-up period of 2 years. The main outcome measures were postoperative 1-week, 1-month, 6-month, 1-year and 2-year exodeviation angles with their patterns and success rates. A surgical success was considered an alignment within 10 PDs and sensory success was defined at 100 seconds of arc. RESULTS: The mean deviation angles at postoperative 1 week were 4.7 ± 5.1 PD esodeviation in the BLR group (44 patients) and 1.2 ± 4.2 PD esodeviation in the ULR group (38 patients). The BLR group was significantly more overcorrected than the ULR group (p = 0.001), but postoperative exodrift occurred in the BLR group at 1 week, 1 month, 6 months, 1 year, and 2 years. In the ULR group, the postoperative exodrift occurred at 1 week, 1 month, and 6 months which was followed by stabilized alignment. Surgical success rate at the postoperative 2-year follow-up was 75.0% in the BLR group and 81.6% in ULR group (p = 0.717). CONCLUSIONS: ULR showed less overcorrection and early exodrift up to only 6 months, resulting in stabilization of the alignment afterwards; surgical success rate at the final 2-year follow-up was similar to BLR.

Effect of Inferior Oblique Weakening Procedures Combined with Surgery for Intermittent Exotropia

PURPOSE: To investigate whether combining inferior oblique weakening procedures with bilateral lateral rectus recession as a surgical approach to intermittent exotropia enhances postoperative horizontal angle of deviation over bilateral lateral rectus recession alone. METHODS: Patients were allocated to one of two surgical groups: a bilateral lateral rectus recession group (Group 1) or a bilateral lateral rectus recession with bilateral inferior oblique weakening group (Group 2). Group differences in the angle of distance deviation were evaluated preoperatively and at 3- and 12-months postoperatively. RESULTS: There were no significant differences in preoperative factors or angles of deviation between Group 1 (n = 98) and Group 2 (n = 77); no significant intergroup difference in the angle of deviation was observed at any postoperative time point (p > 0.05). CONCLUSIONS: Combined inferior oblique weakening procedures did not significantly influence the horizontal angle of deviation after surgery for intermittent exotropia. Accordingly, there is no need to revise the surgical amount of lateral rectus recession.

The Surgical Outcomes of Unilateral Lateral Rectus Recession in Recurrent Intermittent Exotropia after Unilateral Recession-Resection

PURPOSE: To evaluate the surgical outcomes of unilateral lateral rectus (LR) recession on the contralateral eye for recurrent intermittent exotropia after unilateral recession-resection (R & R). METHODS: A retrospective analysis of 43 patients was performed. The patients were classified into 2 groups, 18 patients who underwent unilateral LR recession for intermittent exotropia of 18 to 20 prism diopters (PD) after unilateral R & R (reoperation group) and 25 patients who had primary unilateral LR recession (primary operation group). RESULTS: Significant differences in age, gender, refractive error, preoperative deviation, and near stereoacuity were not observed between the 2 groups (p > 0.05). The mean follow-up duration was 14.28 +/- 14.98 months in the reoperation group and 14.68 +/- 12.15 months in the primary operation group. Postoperative deviations were 1.11 +/- 3.89 PD at near distance and 2.00 +/- 4.70 PD at far distance in the reoperation group and 6.44 +/- 5.26 PD at near distance and 7.00 +/- 5.77 PD at far distance in the primary operation group on the final follow-up (p = 0.000, p = 0.004). The final surgical successful rates were 94.4% in the reoperation group and 64.0% in the primary group (p = 0.021). CONCLUSIONS: The long-term surgical results of unilateral LR recession on the contralateral eye was better in patients with recurrent intermittent exotropia of 18 to 20 PD after unilateral R & R than patients who had primary unilateral LR recession.

Comparison between 20 and 25 Prism Diopters in Bilateral Rectus Muscle Recession for Intermittent Exotropia

PURPOSE: To compare the outcomes of bilateral lateral rectus recession between 20 and 25 prism diopters (PD) for intermittent exotropia. METHODS: A retrospective study was performed with a total of 584 patients who underwent surgery for intermittent exotropia and were followed up for more than 12 months. The patients were classified into either the 20 PD group (5 mm bilateral rectus muscle recession [BLR]) or the 25 PD group (6 mm BLR). Successful postoperative motor alignment was defined as within 10 PD of exotropia and 4 PD of esotropia. RESULTS: Cumulative probabilities of surgical success rates for 24 months were 77.9% in the 20 PD group and 54.8% in the 25 PD group, respectively (p < 0.001). Postoperative deviations in recurrence patients were 13.41 +/- 3.64 PD and 14.66 +/- 3.87 PD (p = 0.062) at postoperative 12 months. CONCLUSIONS: All patients with relatively small angle of exodeviation such as 20 PD had a higher success rate and small postoperative exodaviation at 12 months. Therefore, surgery could be considered when the eye is exodeviated with a relatively small angle. However, in the group with the exotropic drift, approximately 2/3 of the preoperative angle of deviation is measured with similar outcomes between preoperative and postoperative angles of deviation.

Result Comparison after Reoperation in Recurrent Exotropia According to the Type of First Operation

PURPOSE: To investigate and compare the clinical courses and surgical success rates of secondary operations in recurrent exotropia according to the type of first operation for correction of exotropia. METHODS: A retrospective chart review was performed for all patients with recurrent exotropia of the basic or pseudodivergence excess types. In group A (36 patients), bilateral lateral rectus (LR) recession was performed as the first operation and uni- or bilateral medial rectus (MR) resection was performed as the second operation. In group B (19 patients), unilateral LR recession-MR resection (R&R) was performed as the first operation and LR recession or R&R in contralateral eye as the second operation. RESULTS: There were no significant differences between the 2 groups when considering age at each operation, frequency of the amblyopia, prescription of prism, time interval for recurrence and reoperation and the final and cumulative success rates. No postoperative complications were observed in either group. The mean number of used muscles for the first and second operation was 3.9 +/- 0.4 in group A, and 3.4 +/- 0.5 in group B (p = 0.001). Mean time interval for occurrence of postoperative orthophoria was 3.7 +/- 6.2 months in group A and 6.5 +/- 16.2 in group B (p = 0.047). In group B, the incidence of esodeviation tended to increase after postoperative 1 month. CONCLUSIONS: The final success rates of reoperation between the 2 types of the first operation in recurrent exotropia were similar. Mean time between postoperative overcorrection of orthophoria was shorter in the group with bilateral LR recession followed by secondary MR resection than in the other group. Unilateral R&R followed by LR recession or R&R in contralateral eye may be more helpful to decrease the number of used muscles than in the bilateral LR recession followed by secondary MR resection.

Result Comparison after Reoperation in Recurrent Exotropia According to the Type of First Operation

PURPOSE: To investigate and compare the clinical courses and surgical success rates of secondary operations in recurrent exotropia according to the type of first operation for correction of exotropia. METHODS: A retrospective chart review was performed for all patients with recurrent exotropia of the basic or pseudodivergence excess types. In group A (36 patients), bilateral lateral rectus (LR) recession was performed as the first operation and uni- or bilateral medial rectus (MR) resection was performed as the second operation. In group B (19 patients), unilateral LR recession-MR resection (R&R) was performed as the first operation and LR recession or R&R in contralateral eye as the second operation. RESULTS: There were no significant differences between the 2 groups when considering age at each operation, frequency of the amblyopia, prescription of prism, time interval for recurrence and reoperation and the final and cumulative success rates. No postoperative complications were observed in either group. The mean number of used muscles for the first and second operation was 3.9 +/- 0.4 in group A, and 3.4 +/- 0.5 in group B (p = 0.001). Mean time interval for occurrence of postoperative orthophoria was 3.7 +/- 6.2 months in group A and 6.5 +/- 16.2 in group B (p = 0.047). In group B, the incidence of esodeviation tended to increase after postoperative 1 month. CONCLUSIONS: The final success rates of reoperation between the 2 types of the first operation in recurrent exotropia were similar. Mean time between postoperative overcorrection of orthophoria was shorter in the group with bilateral LR recession followed by secondary MR resection than in the other group. Unilateral R&R followed by LR recession or R&R in contralateral eye may be more helpful to decrease the number of used muscles than in the bilateral LR recession followed by secondary MR resection.

The Effect of Bilateral Slanted Lateral Rectus Recession in Exotropia with Near-Far Disparity

PURPOSE: To evaluate the efficacy of slanted recession of the lateral rectus (LR) muscle for exodeviation with larger deviation angle at near than far fixation. METHODS: A retrospective chart review was conducted of 31 patients. Seventeen patients underwent slanted LR recession, the upper fiber of the LR was recessed according to the distance deviation angle and the lower fiber was recessed according to the near deviation. Fourteen patients underwent classic recession. To evaluate the effect of slant LR recession, postoperative ocular alignment between them was checked at 1 week, 1 month, 3 months and 6 months after operation. RESULTS: At the postoperative 6 months, bilateral slanted LR recession reduced the mean exodeviation at near from 33.82 PD to 7.29 PD, and same amount recession group reduced 33.67 PD to 11.13 PD. The far deviation change was from 25.59 PD to 2.59 PD, 23.67 PD to 4.00 PD in each group. The change of near-distance difference was from 10.29 PD to 4.71 PD in slanted recession group, and 9.67 PD to 7.93 PD in same amount recession group, showed that slanted recession group reduced angle more significantly (p = 0.002). Success rate was 35% in bilateral slanted LR recession group, 7% in classic recession group, showed that slanted recession group had significantly high success rate (p < 0.05). CONCLUSIONS: Bilateral slanted LR recession effectively reduces near and distance exodeviation angle, and reduces near-distance incomitance more superior to classic bilateral LR recession technique.

Contemplation of the Surgical Normogram of Lateral Rectus Recession for Exotropia Associated with Superior Oblique Palsy

PURPOSE: To suggest a surgical normogram for lateral rectus recession in exotropia associated with unilateral or bilateral superior oblique muscle palsy (SOP). METHODS: We retrospectively reviewed the charts of 71 patients with exotropia who were successfully corrected over one year. Each patient had undergone unilateral or bilateral rectus recession associated with uni- or bilateral inferior oblique (IO) 14 mm recession, using a modified surgical normogram for lateral rectus (LR) recession, which resulted in 1 to 2 mm of reduction of LR recession. We divided all patients into 2 groups, the 34 patients who had undergone LR recession with unilateral IO (UIO) recession group and the remaining 37 patients who had undergone LR recession with bilateral IO (BIO) recession group. Lateral incomitancy was defined when the exoangle was reduced by more than 20% compared to the primary gaze angle. The surgical effects (prism diopters [PD]/mm) of LR recession were compared between the two groups using the previous surgical normogram as a reference (Parks' normogram). RESULTS: The mean preoperative exodeviation was 20.4 PD in the UIO group and 26.4 PD in the BIO group. The recession amount of the lateral rectus muscle ranged from 4 to 8.5 mm in the UIO group and 5 to 9 mm in the BIO group. Lateral incomitancy was noted as 36.4% and 70.3% in both groups, respectively (p = 0.02). The effect of LR recession was 3.23 +/- 0.84 PD/mm in the UIO group and 2.98 +/- 0.62 PD/mm in the BIO group and there was no statistically significant difference between two the groups (p = 0.15). CONCLUSIONS: Reduction of the LR recession by about 1 to 2 mm was successful and safe to prevent overcorrection when using on IO weakening procedure, irrespective of the laterality of SOP.

Change of Strabismus Angle and Deviation After Unilateral or Bilateral Lateral Rectus Recession in Exotropia

PURPOSE: To compare the changes in strabismus angle and deviation between two groups: a bilateral lateral rectus recession (Group 1) and a unilateral lateral rectus recession in exotropia (Group 2). METHODS: A retrospective survey was conducted on 198 patients who had received exotropia surgery in our ophthalmology clinic from September 2003 to April 2007. A total of 116 patients were in Group 1, and 82 patients were in Group 2. RESULTS: The average deviations of the first postoperative month and the first postoperative year were -1.96 D +/- 4.75, 2.5 D +/- 7.82 for Group 1 and 0.77 D +/- 2.87, 5.94 D +/- 3.38 for Group 2. Revealing statistical significance between the 2 Groups: Group 1 had 30 failure cases (25.9%) and their 1 postoperative year average deviation was 5.42 D +/- 13.97, while Group 2 showed 24 failure cases (29.3%) and their 1-postoperative-year average deviation was 13.0-79 +/- 3.04. Group 1 had less strabismus angle and a greater standard deviation than Group 2, as Group 1 had more overcorrection. Among the 30 failure cases of Group 1, 9 were overcorrected and 21 were undercorrected, but all 24 failure cases in Group 2 were undercorrected. CONCLUSIONS: The strabismus angle after lateral rectus recession showed a wider variation and a larger difference in bilateral lateral rectus recession than in the unilateral lateral rectus recession.

The Changes of Corneal Astigmatism and Refraction After Horizontal Rectus Muscle Surgery in Intermittent Exotropia

PURPOSE: To investigate changes in corneal astigmatism and refractive power in intermittent exotropia after lateral rectus recession with or without medial rectus resection. METHODS: We compared visual acuity, spherical equivalent, refractive power, astigmatism from cycloplegic refraction, and Orbscan corneal topography in two groups consisting of 40 eyes from 20 patients who underwent bilateral lateral rectus recession (Group 1) and 33 eyes from 33 patients who underwent monocular medial rectus resection with lateral rectus recession (Group 2) immediately preoperatively and at 1 and 4 weeks postoperatively. RESULTS: In Group 1, the refractive power changed +0.12 D on average in the horizontal median and -0.08 D on average in the vertical median at 1 week postoperatively. The refractive power changed +0.07 D on average in the horizontal median and -0.04 D on average in the vertical median at 4 weeks postoperatively. No significant change in the corneal astigmatic axis was detected. In Group 2, the refractive power changed +0.4 D on average in the horizontal median and -0.19D on average in the vertical median, and the corneal astigmatic axis significantly shifted by +0.51 D in the 'with-the-rule astigmatism' direction at 1 week postoperatively (p=0.02). However, the refractive power changed +0.2 D on average in the horizontal median and -0.09 D on average in the vertical median, and the corneal astigmatic axis changed +0.2 D at 4 weeks postoperatively, although these values were not statistically significant. CONCLUSIONS: Postoperative refractive power and corneal astigmatism did not change significantly, as compared to preoperative values, at 4 weeks postoperatively in the lateral rectus recession-only or medial-and-lateral rectus recession group.