Unilateral Lateral Rectus Recession Research Articles

Surgical treatment for residual or recurrent strabismus.

Although the surgical treatment is a relatively effective and predictable method for correcting residual or recurrent strabismus, such as posterior fixation sutures, medial rectus marginal myotomy, unilateral or bilateral rectus re-recession and resection, unilateral lateral rectus recession and adjustable suture, no standard protocol is established for the surgical style. Different surgical approaches have been recommended for correcting residual or recurrent strabismus. The choice of the surgical procedure depends on the former operation pattern and the surgical dosages applied on the patients, residual or recurrent angle of deviation and the operator's preference and experience. This review attempts to outline recent publications and current opinion in the management of residual or recurrent esotropia and exotropia.

Long-term outcomes of unilateral lateral rectus recession versus recession-resection for moderate-angle intermittent exotropia

To compare surgical outcomes of unilateral lateral rectus recession (ULR) and unilateral recess-resect (RR) for moderate-angle intermittent exotropia.

How to understand the excessive lateral rectus muscle recession

Surgical treatments of intermittent exotropia include symmetric bilateral lateral rectus recession, symmetric bilateral medial rectus resection, asymmetric monocular lateral rectus recession and/or medial rectus resection, in which lateral rectus recession is the most common method. The maximum amount of lateral rectus recession, however, is still controversial. Bilateral lateral rectus recession 7-8 mm for 35(Δ)-40(Δ) exotropia and unilateral lateral rectus recession and medial rectus resection for exotropia larger than 40(Δ) are suggested by most doctor usually. But some other doctors advocated augmented bilateral lateral rectus recession (9-14 mm ) for exotropia larger than 50(Δ) or augmented unilateral lateral rectus recession for moderate angle exotropia (30(Δ)-35(Δ)), which brought confusion in practical clinical work. In this paper, we'll focus on the amount of lateral rectus recession, and discuss several common issues related to augmented lateral rectus recession, in order to provide references for the majority of clinicians.

Lateral incomitancy and surgical results in intermittent exotropia

AimTo evaluate the prevalence of lateral incomitance (LI) and its association with surgical outcome in intermittent exotropia.MethodsWe retrospectively surveyed patients who had been followed up for 18 months or more...

Long-term outcomes of unilateral lateral rectus recession versus recess-resect for intermittent exotropia of 20-25 prism diopters

BackgroundThe purpose of this study was to compare surgical outcomes of unilateral lateral rectus recession (ULR) and unilateral recess-resect (RR) for intermittent exotropia of 20-25 prism diopters (PD).MethodsIn this retrospective study, ULR was performed on 82 patients and RR on 98 patients for the treatment of intermittent exotropia of 20-25 PD with a follow-up period of 24 months or more. The main outcome measures were postoperative exodeviation angles and final success rates. A surgical success was considered to be an alignment within 10 PD.ResultsThe mean follow-up duration after the surgery was 53.8 ± 26.4 months in the ULR group and 52.5 ± 27.4 months in the RR group (p = 0.482). The mean deviation angles at postoperative 1 day were -0.49 PD (esodeviation) in the ULR group and -1.98 PD in the RR group. Subsequently, at postoperative 1 week, 1 and 3 months, the deviations became more exotropic in the ULR group than in the RR group (p < 0.05). However, the mean deviation angles at 6 months, 1 and 2 years and at the final follow-up did not significantly differ between the two groups. Surgical success at the final follow-up was achieved for 50 patients (60.9%) in the ULR group and 55 patients (56.1%) in the RR group (p = 0.511).ConclusionsULR is an effective surgical method for treatment of moderate-angle intermittent exotropia of 20-25 PD, showing results similar to those of RR.

Treatment of Consecutive Exotropia: Unilateral Lateral Rectus Recession Combined With Medial Rectus Advancement or Resection

Consecutive exotropia presents a difficult clinical problem, especially when previously recessed medial recti are to be strengthened. Surgical options include advancement, typically with a small resection, and resection alone. The authors retrospectively reviewed records of all patients who underwent a second two-muscle surgery on a single eye for consecutive exotropia. Patients with paralytic strabismus and those with less than 1 month of postoperative follow-up were excluded. In 2003, one of the authors began medial rectus resections without advancements in most cases, whereas a second author continued to perform advancements. Two treatment groups were thus reviewed. Forty-two patients qualified for inclusion, including 23 for the resection group and 19 for the advancement group. Preoperative deviations were similar (P = .35, 95% confidence interval: -2.64 to 9.82). Postoperative deviations averaged 11.4 prism diopters (PD) in the resection group and 11.5 PD in the advancement group (P = .98, 95% confidence interval: -12.2 to 12.3). Forty-eight percent of the resection group and 63% of the advancement group achieved alignment within 10 PD of orthophoria (P = .33, 95% confidence interval: -9.0% to 39%). Surgical results were favorable following both techniques. Although both techniques appear to be adequate, resection of previously recessed medial recti may be preferable because they allow use of standard surgical tables and avoid advancement of inflamed tissue into the palpebral fissure.

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. J Korean Ophthalmol Soc 2014;55(8):1180-1186

Outcome of unilateral lateral rectus recession and medial rectus resection in primary exotropia

BackgroundThe purpose of this study was to measure the success rate of unilateral lateral rectus recession and medial rectus resection in primary exotropia.MethodsThis is an interventional case series of 55 patients with primary exotropia (degree of deviation 15–85 PD), above the age of 5 years. Patients were treated in the Department of Ophthalmology, Jinnah Postgraduate Medical Center, Karachi, Pakistan, during the period of July 2009 to March 2010. All the patients underwent surgical procedure i.e., lateral rectus muscle recession (maximum up to 10 mm) and medial rectus muscle resection (up to 6 mm) of one eye, according to the Park’s method. Surgery was done based on prism cover test measurements obtained at 6 m with appropriate optical correction in place. Patients were re evaluated at one day, one month, two months and six months post operatively. Final outcome was considered at the end of six months at which achievement of ≤10 PD of exotropia was the success. Data was analyzed on SPSS version 17.0.ResultsWe obtained success (≤10 PD) in 42 out of 55 patients (76.4%) and 13 out of 55 patients (23.6%) did not meet our criteria for surgical success (>10 PD). Analysis of success with the type of primary exotropia showed that success was achieved in 22 out of 24 cases of intermittent type (91.6%) and 20 out of 31 cases of constant type (64.5%)(P Value 0.019). The highest percentage of success was achieved in patients with the pre-operative deviation of ≤70 PD i.e., 93.3% (42 out of 45 cases), while none of the patients with the pre-operative deviation of >70 PD (10 out of 10 cases) achieved the criteria for success.ConclusionWe conclude that pre-operative deviation is one of the strongest predictor for favorable surgical outcome. Therefore, eliminating the factors causing error in the correct determination of pre-operative deviation should improve the success and predictability of the surgical outcome. Despite the obstacles in the surgical management of strabismus, our results are encouraging.

Comparison of bilateral lateral rectus recession and unilateral recession resection for basic type intermittent exotropia in children

AimsTo compare surgical outcome of bilateral lateral rectus recession (BLR-rec) and unilateral lateral rectus recession combined with medial rectus resection (R&R) for the basic type of intermittent exotropia (IXT) in...

Comparative study of lateral rectus recession versus recession-resection in unilateral surgery for intermittent exotropia

To compare outcomes of unilateral lateral rectus recession (ULR) vs lateral rectus recession-medial rectus resection (RR) in treatment of small to moderate angle exotropia in children. The medical records of intermittent exotropia patients with exodeviation measuring 20 to 25Δ, and underwent ULR or RR between 2002 and 2010 were retrospectively reviewed. The successful alignment after surgery was defined as esophoria/tropia ≤5Δ to exophoria/tropia ≤10Δ. Surgical outcomes were compared between the ULR group and the RR group. Of 85 patients, 44 underwent ULR and 41 underwent RR. The mean follow-up period was 43.2 months in the ULR group and 45.1 months in the RR group (P = 0.935). Mean preoperative exodeviation at distance and near was 21.9Δ ± 2.0Δ, 22.3Δ ± 3.6Δ in the ULR group and 24.3Δ ± 1.6Δ, 26.1Δ ± 3.8Δ in the RR group, respectively (P < 0.05). The incidence of successful outcome at the last follow-up visit was not significantly different between 2 groups which was 39% in the ULR group and 32% in the RR group (P = 0.650). Reoperation rate for recurrence of exodeviation was 18% in the ULR group and 27% in the RR group (P = 0.437). Reoperation for consecutive esotropia was done in 2 patients of the RR group. Cumulative probability of survival from recurrence did not differ between 2 groups (P = 0.83, log rank test). Surgical outcomes at a mean of 3.7 years were not significantly different between the ULR and the RR group. Unilateral lateral rectus recession could be considered as a primary approach in the treatment of small to moderate angle exotropia.

Medial Rectus Muscle Advancement in Consecutive Exotropia

Purpose: Consecutive exotropia is a frequent consequence of surgery for convergent strabismus that may develop at differing rates postoperatively. Several surgical options on horizontal recti have been proposed, but none report a clearly standardized amount of surgery. The present study provides further results of the medial rectus muscle advancement. Methods: Twenty-eight patients, age range 6 - 55 years, who had undergone unilateral or bilateral medial rectus advancement to the physiological insertion, with or without contemporary unilateral lateral rectus muscle recession, were included in the study. Factors leading to the onset of consecutive exotropia were analyzed. Results: After 2 - 3 years, the overall mean angle reduction was 21.3 prismatic diopters (PD) for distance and 22.8 PD for near, with an effectiveness on near vision lower than expected. Only in the 7 cases with a preoperatively larger exotropia at near (of at least 10 PD), the reduction was 17.0 PD for distance and 24.6 PD for near. In unilateral medial rectus muscle advancement, the mean reduction was 14.3 PD for distance and 16.3 PD for near; in bilateral advancement it was 25.8 PD and 25.2 PD respectively. Conclusion: Medial rectus advancement is preferable to other options, especially in cases with convergence deficit, if no excess of divergence or limitation of bulb rotation is present, for which a lateral rectus muscle recession is indicated. Unilateral and bilateral surgeries are useful for exotropia of about 15 PD and 25 PD respectively. The effectiveness depends weakly or not at all by the amount of the previously executed recession.

Postoperative Changes in Spatial Localization Following Exotropia Surgery

Purpose: To measure changes in spatial localization following exotropia surgery using a computer touch-screen method of measurement.Methods: Enrolled in the study were 60 exotropia patients, all of whom had undergone corrective muscle surgeries under general anesthesia: 37 patients had undergone unilateral lateral rectus or bilateral lateral rectus muscle recession procedures (recession group) and 23 patients had undergone unilateral lateral and medial rectus muscle resection (R&R), or unilateral medial rectus resection only (resection group). We evaluated spatial localization by having patients point to targets on a computer touch-screen before surgery, and 1 day and 1 month after surgery. The pointing error, Δp, is defined as the difference between the actual location of the target and the pointed-to location of the target by unsigned value, was recorded as the mean of five tests. We compared the extent of postoperative changes in Δp between the two groups.Results: The mean Δp before surgery did not differ statistically between the two groups (p = 0.93). One day after surgery, however, the postoperative change in Δp of the resection group compared with that of the recession group (2.0 ± 0.7° and 0.4 ± 0.5°, respectively) was significant (p = 0.01 and p = 0.86 respectively).Conclusions: The ability for spatial localization is decreased in patients immediately following medial rectus resection, but is regained by 1 month following surgery.

Factors predisposing to consecutive esotropia after surgery to correct intermittent exotropia

To investigate the incidence of and factors predisposing to consecutive esotropia after intermittent exotropia surgery, and to prevent the onset of consecutive esotropia. We retrospectively surveyed 226 patients who had been followed up for more than 1year after surgery for intermittent exotropia conducted between February 2005 and September 2010. Consecutive esotropia was defined as an esotropia of at least 10 prism diopters (PD) at distance or near at least once in 2weeks after surgery. Presumed risk factors for consecutive esotropia were analyzed. Gender, age at surgery, average binocular spherical equivalent, anisometropia, high myopia, amblyopia, preoperative angle of deviation, vertical deviation, A-V pattern strabismus, exotropia type, type of surgery, stereopsis, and suppression were investigated to evaluate factors influencing the onset of consecutive esotropia. Consecutive esotropia occurred in 22 patients (9.7%). Significant correlations with occurrence of the condition were found with high myopia (P = 0.013), amblyopia (P = 0.047), preoperative angle of deviation of 25-40 PD at distance (P = 0.016), deviation at distance - deviation at near > 10 PD (P = 0.041), lateral incomitance (P = 0.007), tenacious proximal convergence fusion type (P = 0.001), unilateral lateral rectus muscle recession and medial rectus muscle resection (P = 0.001). High myopia, amblyopia, and lateral incomitance were predisposing factors for consecutive esotropia. Furthermore, the preoperative angle of deviation at distance, differences between the angle of deviation at near and at distance, the type of intermittent exotropia, and the type of surgery affected the incidence of consecutive esotropia. More attention must be paid to patients with such factors.

Astigmatic Changes after Horizontal Rectus Muscle Surgery in Intermittent Exotropia

PurposeTo evaluate the changes of refractive astigmatism after horizontal rectus muscle surgery in intermittent exotropic children.MethodsSixty-nine exotropic patients were retrospectively reviewed. Of those, 35 patients received unilateral lateral rectus recession (BLR group, 35 eyes) and 34 patients received unilateral lateral rectus recession and medial rectus resection (R&R group, 34 eyes). Non-cycloplegic refractions were measured until 6 months postoperatively. Spherical equivalent (SE), J0 and J45 using power vectors were calculated to determine and compare the changes of refractive astigmatism and axis in both groups.ResultsSE significantly decreased after surgery for the first week and did not changed thereafter in both groups (p = 0.000 and p = 0.018, respectively). In BLR group, J0 showed significant changes at the first week and 1 month after surgery (p = 0.005 and p = 0.016, respectively), but in R&R group, J0 changed significantly between 1 week and 3 months postoperatively (p = 0.023 and p = 0.016, respectively). J45 did not change significantly as time passed in both groups (all p > 0.05). There was no statistically significant difference in the magnitude of changes in SE, J0 and J45 between the two groups after the 6-month follow-up (p = 0.500, p = 0.244 and p = 0.202, respectively).ConclusionsHorizontal rectus muscle surgery in intermittent exotropic children tends to induce a statistically significant change in astigmatism in the with-the-rule direction and myopic shift in SE. This astigmatism change seems to occur within the first 3 months after surgery. Thus, astigmatism induced by surgery should be checked and corrected at least 3 months after horizontal strabismus surgery.

The Long-Term Survival Analysis of Bilateral Lateral Rectus Recession Versus Unilateral Recession-Resection for Intermittent Exotropia

To conduct a comparison of the long-term surgical outcomes of bilateral lateral rectus recession (BLR) vs unilateral lateral rectus recession-medial rectus resection (RR) in treatment of intermittent exotropia. Nonrandomized, retrospective case series. Consecutive patients who underwent BLR or RR for treatment of intermittent exotropia between 2002 and 2006 and had ≥2 years' follow-up were recruited. Surgical outcomes were grouped according to postoperative angle of deviation as overcorrection (esophoria/tropia >5 Δ), success (esophoria/tropia ≤5 Δ to exophoria/tropia ≤10 Δ), or undercorrection/recurrence (exophoria/tropia >10 Δ), and were compared between the BLR group and the RR group at postoperative 1 day, 1 month, 6 months, 1 year, and 2 years, and at the final examination. Of 128 patients, 55 underwent BLR and 73 underwent RR. The mean follow-up period was 44.2 months in the BLR group and 47.8 months in the RR group. At 1 day, 1 month, 6 months, 1 year, and 2 years after surgery, surgical outcomes in each group were not different (P > .05) However, the final outcome at a mean of 3.8 years was significantly different between the groups, demonstrating a higher success rate in the BLR group than in the RR group (58.2% vs 27.4%, P < .01). Cumulative probability of survival from recurrence was higher in the BLR group than in the RR group (P = .01, log-rank test). Recurrences were most common within 6 months from surgery; however, after that, recurrences occurred continuously in the RR group and rarely in the BLR group. Surgical outcomes by 2 years after surgery for intermittent exotropia were not different between the BLR and RR groups. However, final outcomes were better in the BLR group than in the RR group. This may be caused by the difference of recurrence rate over time: continuous recurrence of exotropia occurred in the RR group, while recurrence was low in the BLR group after postoperative 6 months.

Initial postoperative deviation as a predictor of long-term outcome after surgery for intermittent exotropia

To determine the relationship between initial postoperative deviation and long-term results after surgery for intermittent exotropia. A nonrandomized, retrospective case series. The records of patients who underwent surgery for intermittent exotropia between 2002 and 2006 and had 2 or more years of follow-up were evaluated. Distance alignment at postoperative week 1 was used to predict long-term surgical outcomes. A successful outcome was defined as no recurrence of exodeviation (exotropia/phoria >15(Δ)) at last follow-up. A total of 81 patients with mean age of 7.2 years at surgery (range, 1.3-16.9) were included. Bilateral lateral rectus recession was performed in 24 patients, unilateral recession and resection in 48, and unilateral lateral rectus recession in 9. At postoperative week 1, 41 patients had orthophoria or undercorrection (0(Δ)-18(Δ) exotropia/phoria; Group A), 28 had esotropia/phoria ≤10(Δ) (Group B), and 12 had esotropia/phoria >10(Δ) (Group C) at distance. At 2 years after surgery, 12 patients (29%) in Group A, 3 patients (11%) in Group B, and none (0%) in Group C had recurrent exotropia. The recurrence rates within 2 years of surgery significantly differed between groups (P = 0.03). The long-term recurrence rates did not significantly differ in the 3 groups after a mean of 51 ± 23 months' follow-up. Although initial overcorrection after intermittent exotropia surgery may be associated with lower probability of recurrence within 2 years after surgery, it cannot predict long-term motor outcomes.

Prognostic factors for recurrence with unilateral recess-resect procedure in patients with intermittent exotropia

To evaluate the prognostic factors, particularly age at the time of surgery, for recurrence after unilateral medial rectus resection and lateral rectus recession (R&R) procedures in patients with intermittent exotropia, or X(T). Medical records of 489 subjects who received unilateral R&R procedures with more than 12 months of follow-up were reviewed. The patients' surgical outcomes with a deviation of less than 10 prism diopters (PD) of exotropia and less than 5 PD of esotropia were defined as a success. Outcomes with more than 11 PD of exotropia were designated as recurrences, and those with esotropia of more than 5 PD after 3 months of operation were noted as overcorrection. The prognostic factors for recurrence were analyzed by the multivariate logistic regression test. Of the 489 subjects, 209 had successful surgical outcomes and 280 had recurrences, whereas overcorrection was not found. Mean age at operation was 8.9 ± 6.5 years, mean preoperative distant X(T) size was 32.9 ± 6.0 PD, and mean follow-up period was 27.5 ± 17.9 months. On the basis of the survival analysis in which survival represented time of recurrence, the mean duration was 31.2 ± 1.7 months. Age at onset, age at surgery, and immediate postoperative alignment proved to be significant factors influencing a favorable outcome by multivariate logistic regression analysis (P<0.05). However, gender, family history, and preoperative deviation size were not significantly predictive of success (P>0.05). In unilateral R&R procedures, increasing patient age at the time of surgery was associated with lower recurrence rates. Recurrence rates also increased with the immediate postoperative angle and with the postoperative angle of deviation at 1, 3, 6, and 12 months.

Outcome study of unilateral lateral rectus recession for small to moderate angle intermittent exotropia in children

Outcome study of unilateral lateral rectus recession for small to moderate angle intermittent exotropia in children

One muscle strabismus surgery

To describe recent evidence from the literature regarding one muscle strabismus surgery for small- to moderate-angle horizontal deviations. The use of one muscle surgery for comitant strabismus had been controversial because of concerns that it may result in a significant number of undercorrections and/or produce ocular incomitance. Recent evidence in unilateral lateral rectus recession for exotropia, unilateral medial rectus recession for esotropia, and unilateral rectus resections for undercorrected or recurrent strabismus and convergence or divergence insufficiency suggests that unilateral rectus muscle surgery is a safe, effective and predictable procedure for small- to moderate-angle horizontal deviations. Future prospective, comparative studies with larger samples in unilateral rectus muscle surgery are still needed. Unilateral rectus muscle surgery is a safe, effective and predictable treatment for small- to moderate-angle horizontal deviations. This procedure limits surgery to one eye, leaves other muscles untouched for repeat surgery, and therefore, should be considered as a primary or alternative approach in the treatment of small- to moderate-angle strabismus.

Combined horizontal rectus muscle minimally invasive strabismus surgery for exotropia

Objective: To evaluate combined horizontal rectus muscle minimally invasive strabismus surgery (MISS) for exotropia. Design: Case series. Participants: Fifty-two consecutive exotropic patients operated on by 1 surgeon with MISS combined unilateral lateral rectus muscle recession and medial rectus muscle plication. Methods: Alignment, binocular single vision, conjunctival injection and swelling, and complications during the first 6 postoperative months were recorded prospectively. Conjunctival swelling and injection on the first postoperative day were scored retrospectively and compared with historic controls operated on with combined recession-plication or recession-resection using a limbal approach. Results: Conjunctival swelling and injection were mainly mild on the first postoperative day and less pronounced than after surgery with a limbal approach (comparison of swelling and injection for MISS vs limbal opening recession-plication p < 0.001 and for MISS vs limbal opening recession-resection p < 0.001). A conversion to a limbal approach was necessary in 3/104 (3%, 95% CI 1%–7%) of all muscles. No scleral perforation or other serious complication was observed, and no patient needed a repeat operation within 6 months (0/49, 0%, 95% CI 0%–6%). Conclusions: This study demonstrates that small-incision, minimal dissection combined recession-plication surgery induces less conjunctival swelling and injection compared with the usual limbal approach.