BACKGROUND AND OBJECTIVE

There is no strict by-the-book rule as to which approach is the best strabismus surgery for patients with sensory exotropia. More commonly, a monocular lateral rectus recession and a medial rectus resection (monocular R & R; MRR) is performed in the eye with a poorer prognosis. Rarely, for larger deviations, a third or fourth horizontal muscle in the better eye is added. This study aimed to determine the outcomes of strabismus surgery performed for sensory exotropia in a tertiary hospital in the Philippines.

The medical records of all patients with sensory exotropia who underwent strabismus surgical correction from January 2015 to December 2019 were retrospectively reviewed.

A total of 29 medical records satisfied the inclusion criteria. Mean age at diagnosis and at the time of surgery were 7.5 ± 11.6 (range: 1 to 68 years) and 12.4 ± 16.2 years (range: 1 to 68 years) years old, respectively, with a mean follow-up of 6.2 months (range: 3 to 24 months). After a mean follow-up of 6.2 months, the overall success (alignment in primary position is within 10 prism diopters of orthotropia) was relatively low, where 34% were successful, 65.5% developed recurrence, and none had overcorrections. Survival plots of both surgeries revealed a decline in success probability in achieving desired alignment six months after surgery.

We reported the surgical outcomes of 29 patients with sensory exotropia. The general trend realized was that the decline in success rates of good alignment was evident beginning six months post-operatively. The retrospective design serves as a limitation and hence, readers should treat results with caution.

OBJECTIVE: Intermittent exotropia (IXT) is the most common form of strabismus that warrants standardized management for better and predictable outcomes. Currently there are no preferred practice guidelines on the non-surgical management of IXT. Among the aforementioned methods, orthoptics is the most favored by optometrists and ophthalmologists based in China and Israel. However, consensus statements on the use of such modality are yet to be established. This study aimed to identify preferred non-surgical management strategies for intermittent exotropia (IXT) among members of the Philippine Society of Pediatric Ophthalmology and Strabismus (PSPOS). METHODS: The survey collected data on respondent and patient demographics, perceived causes of IXT, clinical course, and management preferences. Incomplete responses were excluded, and data were analyzed using frequency distribution and the Fisher test. RESULTS: Forty of 54 (74%) PSPOS members participated, predominantly from urban settings (34 respondents). Most IXT cases were children aged 4 to 11 years. The proportion of pediatric patients was not significantly influenced by respondents’ age (p=0.1628) or practice region (p=0.451). Twenty-one (52.5%) respondents cited fusion defects as the primary cause of IXT. While twenty-one noted an unpredictable course, 14 identified it as a progressive course. Overminus lenses were preferred for younger patients (1-4 years), with an increasing preference for orthoptics in older age groups (5 to>18 years). Pediatric ophthalmologists aged 30 to 40 years (p=0.005) and those with 1 to 5 years of experience (p=0.020) favored overminus lenses for 5-10-year-olds. Preference for overminus lenses was stronger outside the NCR (p=0.044). Furthermore, 90% of respondents said surgery shouldn’t be performed at diagnosis, and 42.5% of respondents were against it for younger ages. CONCLUSION The findings revealed a strong preference for overminus lenses among PSPOS members, with increasing use of orthoptics for older patients. Factors influencing management decisions included respondent age, practice region, and perceptions of IXT’s cause and course. Future randomized controlled trials are essential to evaluate non-surgical interventions and develop comprehensive treatment guidelines.
Human ; ophthalmology ; strabismus ; exotropia

Silver-Russell Syndrome (SRS) is a rare disorder associated with prenatal and postnatal growth retardation with associated characteristic facial and ocular features including strabismus. We report the outcome of strabismus surgery performed for exotropia in a 4-year-old patient with SRS. The patient presented with decreased visual acuity and constant exotropia of the right eye noted since 3 months of age. Systemic SRS characteristics consisted of relative macrocephaly, short stature, forehead prominence and stunted growth pattern. An X-pattern exotropia is consistent with bilateral tight lateral recti muscles with overelevation in adduction of the left eye was present. Patient underwent unilateral right lateral rectus recession and right medial rectus resection for a 50-prism diopter constant exotropia. Patient had a favorable outcome of within 8 prism diopters from orthotropia at 1st, 3rd-, 6th- and 12th-month post-operatively.
Russell Syndrome ; exotropia ; macrocephaly

In this study, we explored the neural mechanism underlying impaired stereopsis and possible functional plasticity after strabismus surgery. We enrolled 18 stereo-deficient patients with intermittent exotropia before and after surgery, along with 18 healthy controls. Functional magnetic resonance imaging data were collected when participants viewed three-dimensional stimuli. Compared with controls, preoperative patients showed hypoactivation in higher-level dorsal (visual and parietal) areas and ventral visual areas. Pre- and postoperative activation did not significantly differ in patients overall; patients with improved stereopsis showed stronger postoperative activation than preoperative activation in the right V3A and left intraparietal sulcus. Worse stereopsis and fusional control were correlated with preoperative hypoactivation, suggesting that cortical deficits along the two streams might reflect impaired stereopsis in intermittent exotropia. The correlation between improved stereopsis and activation in the right V3A after surgery indicates that functional plasticity may underlie the improvement of stereopsis. Thus, additional postoperative strategies are needed to promote functional plasticity and enhance the recovery of stereopsis.
Humans ; Exotropia/surgery* ; Depth Perception/physiology* ; Strabismus/surgery* ; Oculomotor Muscles/surgery*

Objective: To compare the postoperative alignment of patients surgically corrected for esotropia or exotropia 6 weeks and 6 months after surgery. Method: This retrospective study reviewed clinical records of patients who underwent horizontal muscle surgery at the University of the Philippines-Philippine General Hospital from 2010 to 2014. The changes in alignment from 1 week to 6 weeks and from 1 week to 6 months after surgery were compared for overcorrection, undercorrection, and adequate correction groups. ANOVA and Pearson correlation were used. Results: Twenty two esotropia and 10 exotropia patients were included. Overcorrected esotropia patients had an esotropic change in alignment (15.50+13.44 PD after 6 weeks, p=0.026; 25+18.38 PD after 6 months, p=0.008). Under corrected esotropia patients had an exotropic change in alignment (-1.25+5.91 PD after 6 weeks, p=0.026;-4.38+14.16 PD after 6 months, p=0.008). Undercorrected exotropia patients had an esotropic change in alignment (6.67+6.35 PD after 6 weeks, p=0.028; 6+9.85 PD after 6 months, p=0.024). The presence of vertical deviations in esotropia caused an exotropic change in alignment after 6 months (p=0.03). Conclusion Although an exotropic drift is more commonly reported, fusional vergences may account for postoperative alignment changes towards orthotropia.
Esotropia ; Exotropia

PURPOSE: To investigate the recovery period of overcorrection and related factors after surgery in pediatric patients with basic intermittent exotropia (XT). METHODS: Retrospective chart reviews of the medical records of patients who underwent bilateral lateral rectus recession for basic XT were analyzed. Preoperative age, sex, angle of deviation (prism diopters [PD]), and suppression at distance were measured. Patients were observed every week when the angle of deviation was > 2 PD of overcorrection at postoperative day 1. Recovery of overcorrection was defined as improvement of overcorrection with orthotropia. Patients were divided into two groups according to age: younger (group 1) and older (group 2) than 10 years of age. Success was defined as an angle of deviation between 10 PD of exodeviation and 5 PD of esodeviation at the final visit. RESULTS: A total of 88 patients were included. At postoperative day 1, the angle of deviation at distance was −6.9 ± 2.2 PD, and the near angle of deviation was −6.9 ± 2.4 PD. Esodeviation presented as a minus value. The recovery period of overcorrection was 1.9 ± 3.9 weeks and the success rate was 80.7% (71 patients). The success rates of group 1 and group 2 were not statistically significant (p = 0.51). The recovery period of overcorrection in group 2 (2.7 ± 5.9 weeks) was significantly longer than in group 1 (1.8 ± 3.4 weeks) (p = 0.02). CONCLUSIONS: In pediatric adolescents with basic XT, the surgical success rates did not differ significantly according to age, but recovery of overcorrection after strabismus surgery took longer in patients ≥ 10 years of age.
Adolescent ; Esotropia ; Exotropia ; Humans ; Medical Records ; Retrospective Studies ; Strabismus

PURPOSE: To evaluate the efficacy and safety of medial rectus muscle plication compared to resection, coupled with antagonist muscle recession, as treatments for intermittent exotropia (IXT). METHODS: We retrospectively reviewed the charts of IXT patients treated by a single surgeon and followed-up for at least 6 months between September 2016 and February 2017. The patients were divided into three groups: a bilateral lateral rectus muscle recession (BLR) group, a unilateral lateral rectus recession with medial rectus plication (R&P) group, and a unilateral lateral rectus recession with medial rectus resection (R&R) group. Serial changes in ocular alignment at 4–24 weeks after surgery were compared among the groups. In addition, the operative times were assessed. RESULTS: We included 119 patients (mean age 6.65 ± 2.79 years). The preoperative exodeviation was 29.81 ± 7.31 prism diopters (PDs) and did not differ among the groups. The R&P group exhibited significantly less postoperative deviation than the BLR group. The operative time was significantly less for the R&P group (25.77 ± 9.29 minutes) than the R&R group (28.97 ± 5.74 minutes). The success rates were identical among groups at 6 months; no severe adverse events were recorded apart from one case of dellen that improved after application of a topical agent. CONCLUSIONS: Plication may reduce the risk for anterior segment ischemia to a level lower than the risks associated with other procedures, and also facilitate reoperation if necessary. We found that R&P took less time but had success rate similar to BLR and R&R. Thus, medial rectus muscle plication for IXT patients is a valuable alternative procedure when the external rectus muscle requires strengthening.
Exotropia ; Humans ; Ischemia ; Operative Time ; Reoperation ; Retrospective Studies

PURPOSE: We report the outcomes of two- or three-muscle surgery on patients with large-angle exotropia exceeding 45 prism diopters (PDs). METHODS: We retrospectively analyzed data on 45 exotropia patients (> 45 PDs) who underwent two- or three-muscle surgery. We excluded patients with paralytic or restrictive strabismus, A- or V-pattern strabismus, a coexistent oblique dysfunction or nystagmus, and/or a history of prior extraocular muscle surgery. Only patients for whom at least 6 months of follow-up data were available were included. Successful surgery was defined as postoperative esotropia ≤ 5 PD, orthophoria, and exotropia ≤ 10 PD at the last visit. RESULTS: We included 45 patients, of whom 22 and 23 underwent two- and three-muscle surgery, respectively. The mean postoperative deviations were 9.5 and 2.7 PD in the two- and three-muscle groups, respectively; the overall success rates were 54.55% (12/22) and 91.30% (21/23). Subgroup analyses revealed that the surgical success rate of two-muscle operations was 66.67% (12/18) in 45–55 PD patients and 0% (0/4) in ≥ 55 PD patients; the success rates of three-muscle operations were 100% (7/7) and 87.50% (14/16). The success rate did not differ significantly between those with postoperative deviations of 45–55 PD (p = 0.137), but did between those who underwent two- and three-muscle operations to treat postoperative deviations of ≥ 55 PD (p = 0.003). CONCLUSIONS: Satisfactory results can be achieved via two-muscle surgery in patients with exotropia < 55 PD. However, for those with exotropia > 55 PD, three-muscle surgery is superior to two-muscle surgery. Therefore, large-angle exotropia is optimally treated via three-muscle surgery.
Esotropia ; Exotropia ; Follow-Up Studies ; Humans ; Retrospective Studies ; Strabismus

Pelizaeus-Merzbacher disease (PMD) is a progressive and degenerative chromosomal disorder of the central nervous system caused by defective myelin production. Few case reports have been issued on the anesthetic management of PMD, because of its extremely low incidence. We anesthetized a 13-year-old female patient diagnosed with PMD for ophthalmic surgery because of intermittent exotropia. General anesthesia was induced and maintained with propofol and sevoflurane in air and oxygen. Rocuronium was administered to facilitate orotracheal intubation, and residual neuromuscular blockage was reversed with pyridostigmine. Between emergence to 24 hours postoperatively, her muscle power completely recovered and no unpredictable events occurred. Summarizing, anesthesiologists should be concerned about the high possibility of aspiration, spasticity, and seizure during the perioperative period in patients with even mild PMD. Appropriate preoperative evaluation, intraoperative monitoring, and choice of proper anesthetic drugs enable safe anesthesia in patients with PMD.
Adolescent* ; Anesthesia ; Anesthesia, General* ; Anesthetics ; Central Nervous System ; Chromosome Disorders ; Exotropia ; Female ; Humans ; Incidence ; Intubation ; Monitoring, Intraoperative ; Muscle Spasticity ; Myelin Sheath ; Oxygen ; Pelizaeus-Merzbacher Disease* ; Perioperative Period ; Propofol ; Pyridostigmine Bromide ; Seizures

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.
Child ; Diplopia ; Exotropia ; Eye Movements ; Follow-Up Studies ; Humans ; Medical Records ; Methods ; Ocular Motility Disorders ; Retrospective Studies