Nonsurgical Consecutive Exotropia Following Childhood Esotropia: A Multicentered Study.

PURPOSE: Nonsurgical consecutive exotropia (NCX) occurs when an esotropia (ET) spontaneously converts to exotropia (XT) without surgical intervention. Although NCX is considered to occur in early-onset accommodative ET with high hyperopia, consensus on causation is lacking. We report the clinical characteristics of NCX and assess the response to conservative management. DESIGN: Retrospective, multicenter, observational case series. METHODS: Patients aged 6 months and older with an initial diagnosis of ET who converted to XT without surgical intervention. Sensory strabismus was excluded. Age, visual acuity, cycloplegic refraction, glasses prescriptions, deviation, and binocular vision were collected. RESULTS: Forty-nine children were included with a mean age of 3.5 ± 1.6 years and 8.4 ± 3.6 years at the time of ET and NCX, respectively. Mean refractive error was +4.40 ± 2.13 diopters (D) and +4.05 ± 2.74 D at the time of ET and NCX, respectively. Accommodative ET occurred in 60% of cases, and only 35.7% were high hyperopes. All but 1 patient presented with XT at distance. In response to the XT, a mean decrease in hyperopic prescription of 1.55 ± 0.48 D was given (N = 17); only 1 case reverted to ET. Eventually, 43% underwent XT surgery, with similar rates between those who had refractive management and those who did not. CONCLUSIONS: NCX occurs in both accommodative and nonaccommodative ET; high hyperopia is present in only one-third of cases. On average, drift to XT occurs within 5 years. Refractive management has a modest result. No predictive risk factors were identified. Our findings challenge hyperopia-linked theories of causation. Nonrefractive explanations, such as the role of the vergence system, deserve further study.

Comparison of Unilateral Versus Bilateral Lateral Rectus Recession for Small Angle Intermittent Exotropia: Outcomes and Surgical Dose-Responses.

PURPOSE: To compare the surgical outcomes of unilateral lateral rectus recession to bilateral lateral rectus recession for small angle intermittent exotropia. METHODS: This was a retrospective cohort study of pediatric patients with an intermittent exotropia between 16 and 20 prism diopters (PD) who underwent unilateral lateral rectus recession or bilateral lateral rectus recession at a single tertiary care pediatric hospital. The primary outcome was success (exotropia < 10 PD of esotropia < 5 PD, no decrease in stereopsis > 0.6 log arcsec, and no reoperation) at 12 months postoperatively. Secondary outcomes included survival analysis of time to surgical failure, surgical dose-response, and improvement in central fusion or stereopsis. RESULTS: At 12 months, successful outcomes were achieved in 13 of 27 patients (46%) in the bilateral lateral rectus recession group and 19 of 28 patients (70%) in the unilateral lateral rectus recession group, which was not a statistically significant difference (P = .10). Survival analysis showed a trend toward a higher rate of failure in the bilateral lateral rectus recession group compared to the unilateral lateral rectus recession group (P = .04). The mean surgical dose-response was 1.7 PD/mm at 1 week and 1.0 PD/mm at 12 months for the bilateral lateral rectus recession group, and 2.0 PD/mm at 1 week postoperatively and 1.4 PD/mm at 12 months postoperatively for the unilateral lateral rectus recession group. There were no cases of long-term postoperative lateral incomitance in either group. CONCLUSIONS: Unilateral lateral rectus recession and bilateral lateral rectus recession have similar success rates for small angle intermittent exotropia after at least 12 months of follow-up. Randomized controlled trials in surgical management of intermittent exotropia should consider unilateral lateral rectus recession as a treatment arm. [J Pediatr Ophthalmol Strabismus. 2022;59(5):350-355.].

Ocular motility disturbances after glaucoma drainage device implantation for paediatric glaucoma: a cross-sectional study.

AIM: To grade extraocular motility in the field of action of each extraocular muscle following superotemporal glaucoma drainage device (GDD) implantation in a paediatric population and to investigate which drainage device (Ahmed vs Baerveldt) yields less extraocular motility disturbance. METHODS: Cross-sectional study of children with a GDD implanted consecutively by a single surgeon who underwent ocular motility examination by two masked orthoptists. Ductions in the cardinal positions were graded. Ocular alignment, visual acuity, binocularity, stereopsis and intraocular pressure were also measured, and patient charts were reviewed. RESULTS: Thirty children each had one eye included. Twenty-one eyes had an Ahmed GDD and 9 had a Baerveldt GDD. Mean time between GDD insertion and ocular motility exam was 68 months in the Ahmed group and 19 months in the Baerveldt group. Exotropia was present in 46% and vertical heterotropia in 46% of children post-GDD insertion. Thirty-three percent of eyes had a moderate or severe limitation of elevation in abduction, 30% of elevation in adduction, 10% of abduction and 10% of adduction. There was a trend towards more eyes in the Ahmed group (62%) having at least a moderate limitation in ocular motility (-2 or worse; scale -1 to -4) compared with the Baerveldt group (22%). CONCLUSION: Strabismus is common in children with GDDs. Our motility and alignment findings are consistent with either a mass effect of the device and bleb and/or scarring beneath the plate in the quadrant of the GDD causing dysmotility, most commonly limitation towards the GDD.

Endophthalmitis after strabismus surgery: incidence and outcome in relation to age, operated eye muscle, surgical technique, scleral perforation and immune state.

PURPOSE: Identify risk factors for endophthalmitis after strabismus surgery (EASS) and relate these to incidence and outcome. METHODS: Ophthalmologists, who had operated, diagnosed or treated EASS, completed a case record form with 71 questions in six domains: Preoperative, Surgery, Perforation, Postoperative, Outcome and Experts' opinion. To estimate the age-specific incidence per number of strabismus operations in the Netherlands during 1994-2013, the age distribution of Dutch cases was compared with the age-specific rates of strabismus surgery in the Dutch Registry of Strabismus Operations and with population data. Exploratory data analysis was performed. The immune state was evaluated in six patients. Five enucleated eyes were studied histopathologically. RESULTS: None of the 26 patients (27 eyes with EASS) were between 9 and 65 years old, except for one patient with retinal haemorrhage followed by endophthalmitis. In the Netherlands during 1994-2013, the rate of EASS was approximately one per 11 000 strabismus operations, but one per 4300 for children aged 0-3 and one per 1000 for patients 65 and older. Endophthalmitis was diagnosed on postoperative day 1-4 in children aged 0-3. In all 15 children aged 0-5, the 16 affected eyes were phthisical, eviscerated or enucleated. The involved eye muscle had been recessed in 25 of 27 cases. It was a medial rectus in 15 of 16 children aged 0-6. It was a lateral (6), inferior (2) or medial (1) rectus in elderly. Scleral perforation went unnoticed in all children (no record in three) and in two of seven elderly (no record in two). Histopathology showed transscleral scarring compatible with scleral perforation in four patients but, in a two-year-old girl who had EASS together with a transient medial rectus palsy, the sclera underneath the former suture tract was not perforated but did contain the long posterior ciliary artery. CONCLUSIONS: Endophthalmitis after strabismus surgery (EASS) affects children and elderly, with a grave outcome in young children. It occurs after recession of the medial rectus muscle in children, and it may occur without scleral perforation. Age and perforation are key determinants that interact with other factors that determine the occurrence and fulminance of EASS.

Population trends in adult strabismus surgery.

OBJECTIVE: To review the trends in adult strabismus procedures in Ontario from 2000-2013. DESIGN: Population-based, retrospective data analysis. PARTICIPANTS: All patients 18 years or older who underwent a strabismus related procedure in Ontario and all ophthalmologists who performed these procedures from 2000-2013. METHODS: Ontario Health Insurance Plan billing claims for strabismus procedures were collected and subdivided by number of muscles repaired, the use of adjustable sutures, repeat procedures, and pharmacological injection of the extraocular muscles adjusted by the total adult population. The number of ophthalmologists performing adult strabismus surgery was also analyzed, subdivided by high-volume and low-volume surgeons. RESULTS: From 2000-2013, per 100 000 adult population, the number of total strabismus surgeries in Ontario increased 26.0%; single-muscle surgery increased 24.2%, 2-muscle surgery increased 43.1%, and 3 or more muscle surgery increased 3.8%. During the study period, strabismus procedures using adjustable sutures increased 30.3%, and repeat procedures increased 19.1%. The number of surgeons performing adult strabismus surgery decreased 30.0% from 2000-2013. In 2013, 92.6% of surgeries were performed by 35.7% of surgeons who performed adult strabismus surgery. CONCLUSION: From 2000-2013, more strabismus surgery was performed in adults by fewer surgeons, including procedures using adjustable sutures and repeat procedures. These increases may be due to increases in health care funding and a heightened awareness of the functional and psychosocial benefits of strabismus surgery.

What Did They Know Then? A Journey Among the Giants of the Past.

Dr. Richard Scobee has the honorary title "The Father of American Orthoptics." In addition to his numerous accomplishments in his academic career, he had hobbies that included collecting historical stamps. In tribute to his love of things past, this lecture will delve into the remote history of ophthalmology, to see what eminent pioneers knew and wrote about eye muscle disorders and binocular vision in their treatises. Our journey will include eight personalities and their works, ranging from the 7th century through to the early 19th century, and will encompass Europe, the Middle East, Great Britain, and North America. Analyzing the writings of these masters affords glimpses into the knowledge base and philosophies that were prevalent in different centuries. Many of these individuals were innovators who pushed the boundaries of knowledge. Some of them made advances using intuition and reason, mainly through case experience and case studies, while others used the scientific method to gain new information. In many cases, the words written by these luminaries centuries ago still resonate with us today and guide us in our everyday practices. It is hoped that this journey will be enlightening for orthoptists, ophthalmologists, and allied health personnel, and confirm, as in many areas of science, that we truly stand on the shoulders of giants, the masters from the recent and the distant past.

Idiopathic Enlargement of the Extraocular Muscles in Young Patients: A Case Series.

PURPOSE: To describe a case series of enlarged extraocular muscles in young patients. DESIGN: Retrospective interventional case series. METHODS: Study involves 6 young patients who presented with atypical restrictive strabismus and reduced eye movements. Examination, neuroimaging, biochemistry results, and biopsy results are presented. The surgeries are described, and the follow-up over 1-20 years is presented. RESULTS: All 6 patients had enlarged extraocular muscles that caused restrictive strabismus. The patients had no significant medical history. There was no identifiable underlying pathology on biochemistry tests or muscle biopsy. Three of the patients required multiple surgeries. CONCLUSION: Atypical presentations of strabismus should be investigated for systemic conditions. Neuroimaging of the orbit and brain and a biopsy of the affected muscles should be considered. The patients should be counseled that multiple surgeries may be necessary to improve the strabismus, and it is unlikely that orthotropia will be attained.

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

PURPOSE: To determine if achieving the ideal postoperative target range increases the long-term success of pediatric strabismus surgery. DESIGN: Interventional case series. METHODS: 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 1 week and at a minimum of 6 months 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 1 week 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. RESULTS: We included 352 patients with mean follow-up of 18 months. 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). CONCLUSION: Achieving the ideal target range within 1 week after surgery is associated with a high rate of long-term success in exotropia surgery in children.

The accuracy of anterior segment optical coherence tomography (AS-OCT) in localizing extraocular rectus muscles insertions.

PURPOSE: To evaluate the accuracy of the anterior segment optical coherence tomography (AS-OCT) in measuring the distance from the limbus to the insertion of primary and previously operated rectus muscles in children. METHODS: In this prospective, double masked, observational study the distance of the extraocular muscle insertion from the limbus measured by AS-OCT preoperatively was compared to intraoperative measurement using the surgical calipers. Consecutive patients 4-18 years of age undergoing primary or repeat strabismus surgery on horizontal or vertical rectus muscles between September 2013 and May 2014 were included. Patients with any condition that interfered with imaging were excluded. Participants were asked to look in the direction opposite to the muscle to ensure that the middle third of the muscle was being imaged and measured. RESULTS: A total of 65 muscles were evaluated, including 9 muscles undergoing reoperation and 10 vertical rectus muscles. Of these, 62 muscles were successfully imaged. In all reoperated eyes, the AS-OCT measurements were within 1 mm of the intraoperative measurements. Overall, 89.7% (95% CI, 78.8%-96.1%) of the measurements were within the 1 mm difference considered "clinically acceptable." The intraclass correlation coefficient comparing the reliability of the AS-OCT measurements with intraoperative measurements was 0.73 (95% CI, 0.53-0.85), or "good" agreement. CONCLUSIONS: AS-OCT can accurately detect rectus muscle insertions in primary or previously operated cases in children as young as 4 years of age.

Cyclic strabismus in adults.

Cyclic strabismus is a rare condition that usually occurs in children and is characterized by alternating intervals of straight and strabismic eyes. In adults with the condition, strabismus surgery often eliminates the cycles. We report a case of adult-onset cyclic esotropia that was converted into a cyclic exotropia.

Achieving postoperative target range increases success of strabismus surgery in adults: a case for adjustable sutures?

BACKGROUND/AIMS: To evaluate the role of achieving immediate target angles on the success of strabismus surgery. METHODS: We performed a retrospective cohort study of all patients over 12 years old undergoing strabismus surgery with either adjustable or non-adjustable sutures. Target angle for patients with esotropia and vertical deviation was within 4 prism dioptres (PD) of orthotropia and for patients with exotropia between orthotropia and 8 PD of esotropia. Success was defined as alignment within 10 PD for horizontal rectus surgery and within 5 PD of orthotropia for vertical rectus surgery, without diplopia or reoperations. The main outcome measure was surgical success rate. RESULTS: Three hundred and fifty-three patients were included in the study with mean follow-up of 13.9 (4-132) months. Patients achieving the target angle immediately postoperatively had higher success rate than patients who did not (83.6% vs 63.7%, p<0.0001, OR 2.9, 95% CI 1.8 to 4.9). When target angle was achieved, adjustable and non-adjustable sutures had similar success (84.8% and 80.9%, respectively, p=0.46, OR 1.3, CI 0.58 to 2.9). However, patients undergoing adjustable surgery were more likely to obtain the target angle (75.5% vs 54%, p<0.0001, OR 2.7, CI 1.7 to 4.2). Success for exotropia surgery was significantly higher when the immediate target angle was achieved (86.4% vs 58.7%, p<0.0001, OR 4.47, CI 2.3 to 8.6). For esotropia and vertical deviations, a similar beneficial effect was not shown (p=0.31, OR 1.6, CI 0.65 to 4.0 and p=0.33, respectively). On multiple logistic regressions, sex, amblyopia, binocularity and reoperations were not significant factors in surgical success. CONCLUSIONS: Our results suggest that achieving the immediate target angle is the most significant factor in the success of strabismus surgery for exotropia. Adjustable suture surgery results in higher proportion of patients achieving this target angle.

Outcomes of three different vertical rectus muscle transposition procedures for complete abducens nerve palsy.

PURPOSE: To compare the efficacy of three different vertical rectus muscle transposition (VRT) techniques performed as a sole procedure to correct ocular alignment and improve abduction in cases of complete abducens nerve palsy. METHODS: The medical records of patients with complete abducens nerve palsy who underwent one of three different VRT procedures without simultaneous medial rectus weakening over a period of 20 years were retrospectively reviewed. The following procedures were used: full-tendon transposition (FTT), FTT with 4 mm resections before reinsertion (FTTR), and FTT with myopexy sutures (FTTM). We recorded the pre- and postoperative alignments, limitations of adduction and abduction, and complications. Follow-up was at least 6 months. RESULTS: A total of 26 patients (age range, 8-74 years) were included: 25 unilateral and 1 bilateral. Follow-up ranged from 6 to 21 months. Among 25 patients having unilateral surgery, the mean changes in esotropia were: 36.0(Δ) for FTT (n = 9), 46.4(Δ) for FTTR (n = 7), and 41.3(Δ) for FTTM (n = 9). Mean improvements in abduction grading were 0.94 for FTT (9 eyes), 1.64 for FTTR (7 eyes), and 1.41 for FTTM (11 eyes). For both measures the means were not significantly different. Three patients (2 FTT and 1 FTTM) had new postoperative vertical tropias >3(Δ). Only 1 patient (with FTTR) had an overcorrection. CONCLUSIONS: FTTR corrected the most esotropia and improved abduction to the greatest degree, with the advantages of a low risk of creating a new vertical deviation and avoiding the risks of extra scleral sutures.

Surgical management of strabismus in Duane retraction syndrome.

SUMMARY: While Duane retraction syndrome (DRS) is relatively common, surgical management of the associated strabismus can be challenging because of the lack of abduction/adduction, the variable severity of muscle contracture, and the variety of clinical presentations. In this workshop a panel of experienced surgeons provide their perspective and practical tips on the management of strabismus in patients with DRS.

Localising rectus muscle insertions using high frequency wide-field ultrasound biomicroscopy.

AIM: The ultrasound biomicroscope (UBM) can accurately locate an extraocular muscle (EOM) insertion. The authors compared the accuracy of the Sonomed UBM (SUBM), a new 'wide-field ultrasound biomicroscope', with the older model Humphrey UBM (HUBM) in localising EOM insertions and compared their ranges of detection of muscle insertions. METHODS: Prospective, double-masked, observational study of 27 patients undergoing primary (n=40 muscles) or repeat (n=10 muscles) horizontal or vertical rectus muscle surgery. EOM insertional distances were measured with SUBM, and then intraoperatively with callipers. A Bland-Altman analysis and intraclass correlation coefficient were used to compare the SUBM and surgical data. RESULTS: For all muscles, the differences between SUBM and surgery measurements were less than 1.0 mm. The mean of the SUBM insertion distances was 6.67 mm (SD 1.65 mm) versus 6.7 mm (SD 1.6 mm) at surgery. The intraclass correlation coefficient showed 'excellent' correlation between the two sets of data and was higher than that reported with HUBM. The image quality with the SUBM was superior to the HUBM, and its range of field was much larger (14×18 mm vs 5×6 mm). CONCLUSION: The SUBM with its smaller, more manoeuvrable probe handpiece and a wider scanning field was more accurate in detecting muscle insertions compared with HUBM.

Utility of adjustable sutures in primary strabismus surgery and reoperations.

PURPOSE: To evaluate the success of adjustable suture (AS) and nonadjustable suture (NAS) strabismus surgery in primary procedures and reoperations. DESIGN: Retrospective case series. PARTICIPANTS: Four hundred four patients older than 12 years who underwent strabismus surgery over a 13-year period. METHODS: All eyes underwent the same hang-back suturing technique by a single surgeon (S.P.K.) in both the AS and NAS groups. Success was defined as alignment within 10 prism diopters (PD) for horizontal recti and within 5 PD of orthophoria for vertical recti without diplopia or further surgery. MAIN OUTCOME MEASURES: Surgical success rate of AS and NAS primary surgery or reoperations was the primary outcome measure. Effects of amblyopia, binocularity, and strabismus type on success were secondary outcome measures and were analyzed using multiple logistic regression. RESULTS: Patients in the AS group required adjustment in 28.8% of cases. Higher overall success was seen with AS (77.7%) compared with NAS (69.1%) surgery, although this did not reach significance (P = 0.059). Overall success for AS in exotropia surgery (80.8%) was significantly higher than that in the NAS group (65.9%; P = 0.011). This was because of higher success in patients undergoing primary surgery (82.5% vs. 50%; P = 0.003), but not in patients undergoing reoperation (80.2% vs. 77.6%; P = 0.71). On multiple regression analysis, male gender and not having a mechanical or neurogenic cause for strabismus were significant factors for a successful outcome. Overall, other factors including amblyopia, binocularity, strabismus type, and primary or reoperation were not significant. CONCLUSIONS: These results suggest that primary surgery in adults with exotropia has a more successful outcome with AS surgery. This advantage was not present with esotropia and vertical deviations in this series.