Esotropic Patients Research Articles

Choroidal Thickness in Strabismus and Amblyopia Cases

ABSTRACTPurpose: The aim of our study was to examine the effect of hypermetropia and anisometropic, exotropic, and esotropic amblyopia on choroidal thickness. Methods: A prospective, cross-sectional, comparative study of 120 children under the age of 16 years was conducted. Choroidal thickness was measured in patients with hypermetropia, anisometropia, esotropia, exotropia, and controls. Results: The mean subfoveal choroidal thickness in the control and hypermetropia groups was 323.9±69.0 µm and 348.9±64.5 µm, respectively. Mean choroidal thickness in amblyopic and fellow eyes was 387.4 and 351.9 µm in anisometropic, 353.8 and 338.7 µm in exotropic, 347.5 and 336.5 µm in esotropic, and 389.3 and 359.3 µm in esotropic+anisometropic groups, respectively. Choroid was significantly thicker in amblyopic eyes of anisometropic group compared to fellow (P=0.004) and control (P=0.03) eyes. The difference of choroidal thickness was not significant between both eyes and when compared to control eyes in the other groups. Conclusions: Anisometropic amblyopic eyes had thicker choroids compared to controls and fellow eyes. However the choroidal thickness was not significantly different between amblyopic and fellow eyes of esotropic or exotropic patients.

Esotropia with an accommodative component after surgery for infantile esotropia compared to primary accommodative esotropia

To compare the clinical outcomes of patients with an esotropia with an accommodative component after infantile esotropia surgery and patients with primary refractive accommodative esotropia. The medical records of patients with postoperative (secondary group) and primary refractive accommodative esotropia (primary group) were reviewed retrospectively. Changes in ocular alignment, refractive error, weaning rate, decompensation rate over time, and sensory outcomes were compared. The overall change in ocular deviation with glasses correction was -0.5Δ/year in the secondary group and -0.2Δ/year in the primary group (P=0.010). The overall change in spherical equivalent refractive error was -0.2 D/year in the secondary group and -0.3 D/year in the primary group (P<0.001). The latest stereoacuity result was poorer in the secondary group than in the primary group (P=0.027). No significant differences in the decompensation or weaning rates were detected between groups. The changes in refractive error and the amount of esotropia over time were different between the secondary group and the primary group. Although refractive error was significantly lower and stereoacuity was poorer in the secondary group compared to the primary group, the majority of patients in the secondary group maintained good control of ocular alignment after hyperopic correction.

Adjustable suture strabismus surgery in pediatric patients using pull-string technique.

BACKGROUND/PURPOSE:The concept of adjustable suture has been developed in strabismus surgeries for nearly four decades. This technique is not yet universally embraced by strabismus surgeons, especially in pediatric patients. The aim of this study is to describe and evaluate the application of the adjustable suture with pull-string technique in pediatric patients.METHODS:A retrospective medical record review was conducted for patients aged 18 years and under who received adjustable suture strabismus surgery using short tag sliding noose with pull-string technique. For the analysis, the patients were arbitrarily divided into three age groups: 6 years and younger, between 6 and 12 years, and 12 years and older. Patients were examined at 1 week and 1, 3, and 6 months after surgery.RESULTS:A total of 123 patients were enrolled in this study. The mean age at the time of surgery was 9.4 years, ranging from 0.7 to 18.4 years. Eighteen (14.6%) patients required adjustment and 105 (85.4%) patients did not require adjustment. The average follow-up was 10.2 months (range, 1–48 months). At their final postoperative follow-up, 93 of 123 (75.6%) patients were within 10 prism diopters of orthophoria. The success rates were 77.6% (66/85) in exotropia patients and 71.1% (27/38) in esotropia patients. The success rates were 76.4% (84/110) for those who receive the procedure as primary surgery and 69.2% (9/13) for those who receive the procedure as reoperative surgery. Of the 18 patients who required adjustment, 16 (88.9%) patients were successful. Of the 105 patients who did not require adjustment, 77 (73.3%) patients were successful.CONCLUSION:This study showed that the pull-string technique provided similar success rate compared to those reported in literature in pediatric patients. The pull-string technique is developed to simplify the postoperative adjustments. Many surgeons encounter difficulties to handle the postoperative adjustments, especially when they need to retrieve the buried subconjunctival adjustable sutures. The obstacles are reduced with the aid of pull string. Using the pull-string technique, the surgeon can perform adjustable suture surgeries in any age group with confidence.

A comparative study of adjustable and non-adjustable sutures in primary horizontal muscle surgery in children

PurposeTo compare the results of using adjustable and non-adjustable sutures in primary horizontal strabismus surgeries in children.MethodsThis randomized control trial included 60 cases of primary horizontal deviation. The adjustable suture (AS) group included 30 patients, and the non-adjustable suture (NAS) group included 30 patients. The follow-up period was at least 6 months. A successful motor outcome was defined as orthophoria or a horizontal tropia of 8 PD or less at both near and far distances. The success rate and ocular drift were recorded and analysed.ResultsThe mean age in the AS group was 3.48±2.37 years at the time of surgery. The mean age in the NAS group was 3.55±2.64 years at the time of surgery. The success rate at the end of 6 months was 86.67% in the AS group and 73.33% in the NAS group (P=0.197). In exotropic patients, there was a mean undercorrection drift of 2.86 PD in the AS group and a mean undercorrection drift of 2.17 PD in the NAS group. In esotropic patients, there was a mean undercorrection drift of 0.26 PD in the AS group and a mean undercorrection drift of 1.83 PD in the NAS group.ConclusionThere was no significant difference between the groups. However, the success rate was clinically higher in the AS group than in the NAS group.

Early alignment versus delayed alignment in patients with hyperopia and esotropia

To compare the clinical outcomes in hyperopic and esotropic patients with and without early alignment after spectacle correction. The medical records of patients with hyperopia and esotropia who were initially treated at a single center with full spectacle correction of their hyperopia from 1994 to 2009 were retrospectively reviewed. Patients with ≤10(Δ) of residual esotropia after 2months were assigned to the early-alignment group; those with >10(Δ) were assigned to the delayed-alignment group. The main outcome measure was final stereoacuity of each group. Of 136 patients who met the inclusion criteria, 85 (63%) were aligned after 2months, whereas 51 (37%) had residual esotropia. The early-alignment group had more patients with high-grade stereoacuity ≤100 arcsec (37% vs 19%) and significantly better stereoacuity results overall (P=0.037). Almost 70% of patients with poor alignment at 2months required strabismus surgery, whereas 30% improved after over 1year in spectacles alone, achieving a final alignment of ≤10(Δ) without surgery. These results suggest that earlier correction of esotropia results in better final stereoacuity. The desire for early correction, however, should be tempered by the knowledge that 30% of patients with poor early alignment may eventually achieve alignment without surgery, a result that should be considered when counseling parents about the need for strabismus surgery.

Pattern of strabismus in a tertiary hospital in Nigeria: a six-year review

Background: Strabismus (ocular misalignment) is frequently seen in clinical practice. Its prevalence varies in different parts of the world with no sex predilection. Stabismus is a significant cause of ocular morbidity. Esotropia is often the commonest form of presentation among children. Aim: To determine the frequency and clinical features of patients presenting with strabismus in the ophthalmic clinic a past 6-year period. Methods: This was a hospital based study of all the patients diagnosed having strabismus in University of Port Harcourt Teaching hospital between January 2007 and December 2013. The medical records of a total of 74 patients who visited the ophthalmic clinic and diagnosed as having strabismus were retrospectively reviewed and subsequently analysed using Statistical Package for Social Sciences (SPSS) version 17 computer soft ware package. Ethical clearance was obtained from the Ethics committee of the University of Port Harcourt Teaching Hospital. Results: A total of 12,334 case files were reviewed in this study. Five thousand one hundred and eighty-one (42%) were males and 7,153 (58%) females. A total of 74 cases had strabismus (0.6%). Twenty- three were males and 51 females (M:F=1:2.2). Twenty-eight (37.8%) had alternating squint, twenty- three (31.1%) had esotropia, twenty- one (28.4%) had exotropia and two (2.7%) had hypertropia. Conclusion: This study confirmed the relatively high frequency of alternating squint and esotropia in patients with strabismus. Keywords: Strabismus, Prevalence, Pattern

Strabismus Amblyopia in Young Cameroonian at their First Visit at Yaounde Hospital Centre-Essos

The management of strabismus in Cameroon is not well developed and the average age of first consultation is beyond the age amblyopia reversal. It is with the aim of improving strabismus management that we undertook this prospective and descriptive study which spanned 11 months. The objective was to describe amblyopia in patients with comitant strabismus at their first visit. Data collected included the age at the first visit, past history, refractive error, and the characteristics of strabismus, amblyopia and strabismus-associated factors. Forty patients were included amongst whom there were 21 females and 19 males. The mean age was 5.5 ± 4.6 years, with extremes of 3 months and 24 years. The hospital prevalence of amblyopia was 1.02%. Esotropia was the most common form of strabismus in 52.5 % of cases. In 37.5% of cases, the onset of strabismus was before the age of six months. Amblyopia was present in 63.7% of cases. It was classified as severe in 29.41% of cases, moderate in 21.57% of cases, and mild in 49.02% of cases. Head tilt was present in 27.5% of cases and nystagmus in 25% of cases. In conclusion, the prevalence of amblyopia is high in our milieu with a higher prevalence amongst esotropic patients. The management of strabismus relies on the wearing of the full cycloplegic correction and requires the full cooperation of the parents.

Modified Y-splitting Procedure for the Treatment of Duane Retraction Syndrome.

Objectives:To present the outcomes of modified lateral rectus Y-splitting combined with either unilateral or bilateral horizontal rectus recession in Duane Retraction Syndrome (DRS) with significant upshoot or downshoot.Ma­te­ri­als and Met­hods:A total of 12 patients including 10 patients with Type I DRS and 2 with Type III DRS underwent modified Y-splitting surgery. Amount of additional recessions varied with the degree of preoperative deviation by intraoperative adjustable suture technique. Preoperatively 3 patients had esotropia (ET), 6 had exotropia (XT), and 3 patients had orthotropia. The mean preoperative deviation was 19.3 prism diopters (PD) (range, 18-20 PD) in ET patients and 19.2 PD (range, 16-20 PD) in XT patients.Re­sults:Postoperatively, all patients had significant correction in horizontal deviation and aligned within 4 PD of orthotropia, and no patients exhibited abnormal head posture. Co-contraction and globe retraction were markedly reduced and abnormal ocular vertical movement disappeared or significantly decreased in all cases. No patients experienced recurrence of ocular motility disorders in the mean 26-month (range, 13-66 months) follow-up period.Conclusion:Modified Y-splitting surgery combined with co-contracting horizontal muscle recession technique seems to be a safe and effective treatment in DRS.

The Effect of Achieving Immediate Target Angle on Success of Strabismus Surgery in Children.

To determine if achieving the ideal postoperative target range increases the long-term success of pediatric strabismus surgery. Interventional case series. Children below 12 years old with horizontal strabismus who underwent surgical correction by recession, resection, advancement, or a combination of both between 1996 and 2011 were included. Alignment was measured within 1week and at a minimum of 6months after surgery. The ideal postoperative target range was defined as 0-8 prism diopters (PD) of esotropia in exotropic patients and within 4 PD of orthotropia in esotropic patients measured within 1week after the surgery. Success was defined as a measurement within 10 PD of orthotropia at the latest postoperative visit. The main outcome measures were surgical success rate and the factors affecting it. We included 352 patients with mean follow-up of 18months. Overall, patients within the target range had a higher success rate than those outside it (75.6% vs 57% P= .0004). This was highly significant for exotropia (P= .0002) but not for esotropia (P= .4). Multiple regression analysis revealed that being within target range was the strongest predictor of long-term success (odds ratio [OR]= 2.3, range 1.4-3.7). Overall, surgeries on patients with esotropia were more likely to be successful than on those with exotropia (OR= 1.9, range 1.2-3), and premature patients had poorer outcomes (OR= 0.2, range 0.1-0.8). Achieving the ideal target range within1week after surgery is associated with a high rate oflong-term success in exotropia surgery in children.

Esotropia associated with high myopia.

The aim of the present article is to describe the pathophysiology of esotropia associated with high myopia, commonly known as heavy eye syndrome, and discuss the preoperative evaluation and surgical options in these complex patients. Numerous studies have looked to determine the cause of esotropia in patients with high myopia. Orbital imaging has shown a nasal displacement of the superior rectus muscle and an inferior displacement of the lateral rectus muscle. As such, traditional resection-recession surgery can be ineffective in these patients. Instead, correcting the deviant muscles paths is necessary. Recent studies have shown that loop myopexy with or without medial rectus recession can be performed without sclera fixation sutures to correct the underlying pathophysiology. Heavy eye syndrome or strabismus fixus is a rare restrictive strabismus. Careful preoperative evaluation must be performed in order to correctly diagnose these patients. If posterior globe prolapse with superior and lateral rectus muscle displacement is seen, loop myopexy can be a well tolerated and effective procedure in treating heavy eye syndrome.

Combining rectus muscle recessions with a central tenectomy to treat large-angle horizontal strabismus

To report the effectiveness of incorporating a central tenectomy on the recessed rectus muscles when treating large-angle horizontal deviations. Patients undergoing recession and central tenectomy from March 2010 to January 2013 were prospectively enrolled. The procedure entails making two longitudinal incisions, each 4 mm, on the muscle adjacent to sutures made during the recession procedure. With recession complete and muscle sutured to the sclera, the central flap (with approximately one-third of the insertion width) is excised. The following variables were analyzed: expected correction (according to surgical dose tables), achieved correction (preoperative deviation minus postoperative deviation), and tenectomy effect (achieved correction minus expected correction). A total of 16 horizontal rectus muscles of 16 eyes of 12 patients were included, 8 with exotropia and 4 with esotropia. No cases of significant limitation in duction in the field of the recessed muscle occurred. In all patients, the median achieved corrections at distance (55(Δ)) and at near (53.5(Δ)) were significantly higher than the median expected corrections (45(Δ) for both distance and near [P = 0.002]). The postoperative deviations at distance and near were lower in the unilateral surgery group (n = 8; statistically significant only for near deviation). The tenectomy effects in the esotropia group for both distance and near were more pronounced than those of the exotropia group (although not statistically significant). In our patients central tenectomy of the recessed rectus muscles increased the effect of recession procedures without limiting ductions. There were possible greater effects in esotropia patients and recession-resection procedures.

Results of Bilateral Medial Rectus Recession for Comitant Esotropia in Patients with Developmental Delay

Purpose: There is paucity of literature on surgical outcomes after strabismus surgery in patients with developmental delay. There is no consensus regarding whether standard surgical tables are applicable to these children. The goal of our study was to determine results of strabismus surgery for esotropia among these children.Methods: Two retrospective cohorts of patients, with developmental delay (excluding Down syndrome) and without developmental delay, who underwent bimedial recession for comitant eso-deviation between January 2005 and January 2011, meeting our criteria, were selected. Amount of surgery performed in these children was compared with standard table. This comparison gave us operated angle of deviation. This operated angle of deviation was expressed as percentage of preoperative angle of deviation to get amount of surgery performed. Response to surgery was defined as percentage of change in angle of deviation after surgery to the operated angle of deviation. Amount of surgery performed, response to surgery, and results were compared between two groups.Results: This study included 25 patients with developmental delay and 53 normal children with comitant esotropia. Age, refractive error, and preoperative angle of deviation were comparable in patients with and without developmental delay. Among patients with developmental delay, on average 72.13% ± 16.08 of angle of deviation was operated; response to surgery gained was 134.06% ± 51.62. In the control group, the average amount of surgery done was 89.08% ± 10.83; response gained was 89.83% ± 22.49. Successful outcome (±10 PD of orthophoria) was noted in 60% patients with developmental delay compared to 73.58% in control group. On average 70.67% ± 17.95 angle of deviation was operated in patients with developmental delay with successful outcome.Conclusion: Surgical outcome in patients with developmental delay is very unpredictable. An exaggerated response to standard amounts of bimedial recession should be anticipated in these patients. Though there was no statistically significant difference, operating for 70.67% ± 17.95 angle of deviation is more likely to be successful.

The benefits, risks, and efficacy of strabismus surgery in adults.

Strabismus surgery in adults achieves satisfactory alignment with one operation in approximately 80% of patients, depending on the specific nature of the problem. Risks of adult strabismus surgery are relatively low, and serious complications are anecdotal and rare. Even if the strabismus has been long-standing, most adults will experience some improvement in binocular function after strabismus surgery. Consequently, adult strabismus surgery should not be considered merely cosmetic in most cases. In esotropic patients, this improvement typically takes the form of an expansion of binocular visual fields; however, some patients may also regain stereopsis. There are many psychosocial benefits to adult strabismus surgery. This is reflected in the finding that the majority of adults surveyed with strabismus would trade a portion of their life expectancy to be rid of their strabismus.

Consecutive esotropia after surgery for intermittent exotropia: the clinical course and factors associated with the onset

BackgroundTo analyse the incidence and factors associated with the onset of consecutive esotropia after surgery for intermittent exotropia, and to investigate its clinical course.MethodsWe retrospectively reviewed the medical records of...

The Accuracy of the PlusoptiX for Measuring Pupillary Distance

Introduction: The plusoptiX photoscreener provides a number of measurements, including an estimate of inter-pupillary distance. We compare the plusoptiX photoscreening measurements of pupillary distance to that of an experienced optician in order to measure the accuracy of this reading.Methods: A retrospective chart review was done on 731 patients ranging in age from 1 to 16 years. Of these, 256 patients had both a plusoptiX photoscreening and a pupillary distance measurement by one of our office opticians.Results: Of the 236 patients evaluated, 142 were orthophoric, 97 were esotropic, and 17 were exotropic. The mean absolute difference for the entire group between the two measurements was 0.3 mm. For the orthophoric patients, this metric was 0.3 mm, while for the esotropic patients it was 0.8 mm. There were too few exotropic patients to obtain reliable statistics.Conclusions: Although the average difference between the optician’s measurements and those provided by the plusoptiX was within 0.5 mm for orthophoric patients, the variability of the measurements provided by the plusoptiX was too great to permit us to recommend the device as an alternative to the optician for routinely dispensing spectacles.

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. J Korean Ophthalmol Soc 2014;55(5):711-718

Real stereopsis test using a three-dimensional display with Tridef software.

PurposeTo investigate horizontal image disparity in three-dimensional (3-D) perception using 3-D animations in normal control patients and patients with intermittent exotropia, anisometropic amblyopia, and partially accommodative esotropia.Materials and MethodsA total of 133 subjects were included. Stereopsis was measured using the Titmus Stereo test (Stereo Optical Inc., Chicago, IL, USA) and a 3-D stereopsis test with a 15 inch 3-D display laptop, adjusting 3-D parameters of 0 mm horizontal disparity to 15 mm horizontal disparity.ResultsWhen compared with normal controls, the average threshold of the 3-D stereopsis test was significantly reduced for esotropia patients (p<0.001) and for anisometric amblyopia patients (p<0.001), compared to normal controls. No significant difference was observed between normal controls and intermittent exotropia patients (p=0.082). The 3-D stereopsis test was correlated with the Titmus Stereo test (Spearman's rho=0.690, p<0.001). Mean difference in stereoacuity was 1.323 log seconds of arc (95% limits of agreement: 0.486 to 2.112), and 125 (92.5%) patients were within the limits of agreement.ConclusionThis study demonstrated that a 3-D stereopsis test with animation is highly correlated with the Titmus Stereo test; nevertheless, 3-D stereopsis with animations generates more image disparities than the conventional Titmus Stereo test. The 3-D stereopsis test is highly predictive for estimating real stereopsis in a 3-D movie theater.

The Initial Factors Influencing Successful Final Stereoacuity in Refractive Accommodative Esotropia

Purpose: To evaluate the initial factors influencing successful final stereoacuity in patients with refractive accommodative esotropia. Methods: The charts of 48 refractive accommodative esotropia patients 2 years of age or older andassessed using the Titmus stereoacuity test were retrospectively reviewed. Hyperopic refractive error on post-cycloplegic refraction, age at first glasses, stereoacuity after refractive correction and amblyopia were categorized and evaluated as the factors influencing final stereoacuity. Results: The mean follow-up period was 43.51 ± 30.02 months. The mean hypermetropia at the initial examination was 4.67 ± 2.18 diopters (D), the mean age at first glasses was 48.09 ± 20.22 months and the mean stereoacuity after refractive correction was 1243.75 ± 1378.24 seconds of arc. The rates of successful stereoacuity at the final visit were 83.3% without amblyopia, 75.0% with mild amblyopia and 42.9% with moderate amblyopia which were statistically significant (p = 0.039). Hyperopic refractive error and age at first glasses were categorized as +1.0 to <3.0 D, +3.0 to <5.0 D, ≥+5.0 D and 2 to <4 years, 4 to <6 years and ≥6 years, respectively, and the rates of successful stereoacuity at the final visit were 83.3%, 66.7%, 61.9% (p = 0.362) and 71.4%, 75.0% and 54.5% (p = 0.334), respectively. Conclusions: The amblyopia at the initial examination was significantly associated with the outcome of stereoacuity at the final visit in patients with refractive accommodative esotropia. J Korean Ophthalmol Soc 2014;55(6):877-881

Plusoptix S08 sensitivity in detecting strabismus as amblyogenic risk factor

Purpose: To evaluate the sensitivity of photoscreener Plusoptix S08 in screening strabismus.Methods: Eighty-three consecutive patients were examined by a single expert to determine the type and amount of the deviation. Then photoscreening was done for all the patients via Plusoptix S08 photoscreener (Plusoptix GmbH, Nuremberg, Germany) on the same day, using the default software for referring the patients.Results: The age range was between 6 months and 40 years. The overall sensitivity of the device to detect strabismus is 70%; it was 25% for exophoria, 67% for esotropia, 73% for exotropia, and 89% in patients who had mixed strabismus. Regarding degree of deviation, sensitivity was 46% in deviations less than 30 prism diopters (PD) and rises while the degree of deviation increases.Conclusions: Our research shows that Plusoptix should not be used solely in evaluating strabismus because its sensitivity decreases significantly specially in esotropic patients with less than 30 PD deviations.

The Stability of the Monofixation Syndrome

To determine etiology, characteristics, and stability of the monofixation syndrome (MFS) in a chart review of 63 consecutive patients in a private practice of pediatric ophthalmology. Retrospective, consecutive chart review. The charts of 63 consecutive patients with MFS, encountered from 2007-2012 followed for a minimum of 3 years were included. Best visual acuity, motor angle deviation at near, fusion, and stereoacuity as recorded on the most recent visit during the follow-up period were examined. Stability of the MFS was determined by comparing the dates of diagnosis with the last examination for those patients who remained stable. Decompensated patients were also studied for characteristics and results of secondary surgery. The etiology of the MFS was esotropia in 58 (92.1%), anisometropia in 2 (3.2%), and exotropia in 3 patients (4.8%). The majority of patients, 57 of 63 (92%), had stable MFS for a mean of 13.9 years. Six esotropic patients decompensated after a mean of 6 years; 5 of these patients were restored to MFS by secondary surgery and 1 spontaneously recovered. Five patients were found to have improved stereoacuity to 60 arc seconds or better by the end of the study. The MFS is a relatively stable binocular status during the first 2 decades of follow-up. A small percentage of patients decompensated, requiring secondary surgery to restore the MFS binocular status. A similar small percentage of MFS patients developed a higher grade of stereoacuity when followed for a sufficient interval of time.