Strabismus

This article presents a surgical technique using a pericardial patch for the permanent repair of severe scleral thinning encountered during strabismus surgery. In the present case scleral thinning resulted from buckle removal. Familiarity with this technique may prove important for the strabismus surgeon treating patients with a history of surface ocular hardware or disease-induced scleral thinning. This video article may be viewed atjaapos.org.

PURPOSE: To report strabismus surgery frequency and outcomes after monocular infantile cataract surgery with or without IOL implantation. METHODS: The Infant Aphakia Treatment Study (IATS) is a randomized, multicenter clinical trial comparing treatment of aphakia with a primary IOL or contact lens in 114 infants with a unilateral congenital cataract. This report is a secondary outcome analysis of ocular motor data from IATS patients who underwent strabismus surgery prior to age 5 years. RESULTS: Strabismus surgery was performed in 45 (39%) patients (contact lens group [CL], 37%; IOL group, 42% [P = 0.70]). The indications for strabismus surgery were esotropia (62%), exotropia (33%), and hypertropia (4%). Infants who underwent cataract surgery at a younger age were less likely to undergo strabismus surgery (28-48 days, 12/50 [24%]; 49-210 days, 33/64 [52%]; P = 0.0037). Of the 42 patients who underwent strabismus surgery, 14 (33%) had a postoperative distance alignment within 8(Δ) of orthotropia at age 5 years. The 5-year visual acuity of children with strabismus was the same whether or not strabismus surgery had been performed (1.10 logMAR with surgery vs 1.00 without [P = 0.71]). CONCLUSIONS: In this study cohort, cataract surgery performed in the first 6 weeks of life was associated with a reduced frequency of strabismus surgery. Strabismus surgery outcomes in this population are guarded. Surgical improvement of strabismus does not appear to influence long-term visual acuity.

INTRODUCTION: Congenital fibrosis of the extraocular muscles type 2 (CFEOM2) is a distinct non-syndromic form of congenital incomitant strabismus secondary to orbital dysinnervation from recessive mutations in the gene PHOX2A. The phenotype includes bilateral ptosis, very large angle exotropia, ophthalmoplegia, and poorly-reactive pupils. Other than amblyopia, afferent visual dysfunction has not been considered part of CFEOM2; however, we have repeatedly observed non-amblyopic subnormal vision in affected patients. The purpose of this study was to document this recurrent feature of the phenotype. METHODS: A retrospective case series (2002-2012). RESULTS: Eighteen patients (four families) were identified; all affected individuals had confirmed homozygous recessive PHOX2A mutations except one individual for whom genetic testing was not done because of multiple genetically confirmed family members. Age at assessment ranged from 5-62 years old (median 10 years old). All patients had decreased best-corrected visual acuity not completely explainable by amblyopia in both the preferred and non-preferred eye. In those patients who had further ancillary testing, visual fields (five patients) and electroretinography (10 patients) confirmed abnormalities not ascribable to amblyopia. CONCLUSIONS: In addition to a distinct form of congenital incomitant strabismus, the phenotype of CFEOM2 includes subnormal vision consistent with retinal dysfunction. This could be the direct result of PHOX2A mutations or a secondary effect of orbital dysinnervation.

Children born very preterm are at greater risk of ophthalmic morbidities, including strabismus, than children born at term. We evaluated perinatal factors associated with strabismus at age 2 years in a large population of infants delivered before 28 weeks' gestation. A total of 996 infants in the multicenter ELGAN (Extremely Low Gestational Age Newborn) study who had a retinal exam in infancy and a developmental assessment at 2 years corrected age are included. Their mothers were interviewed about the pregnancy, and both mother and newborn charts were reviewed. Certified examiners administered the Bayley Scales of Infant Development-II and performed an examination of ocular alignment. Time-oriented logistic regression risk models were created to evaluate the associations of characteristics and exposures with the development of strabismus. Overall, 14% (n = 141) of the children had strabismus at 2 years, and 80% of strabismic children had esotropia. Characteristics associated with strabismus were birth before 26 weeks' gestation, severe fetal growth restriction, and maternal history of aspirin ingestion. Associated postnatal factors included a SNAP-II (Score for Neonatal Acute Physiology) illness severity value ≥30, brain ventriculomegaly, type I retinopathy of prematurity, and ventilator-dependent severe bronchopulmonary dysplasia. Strabismus in very preterm populations is associated with a number of antenatal and postnatal antecedents as well as clinical and imaging correlates indicative of brain damage in these children. Routine ophthalmologic assessments in the early years can allow appropriate and timely interventions.

IMPORTANCE: Understanding the criteria for when strabismus becomes detectable by non-health care professionals could influence the goals for determining the success of surgical intervention and how patients with such misalignments are counseled. OBJECTIVE: To examine the magnitude at which strabismus is detectable by lay observers in an ethnically diverse set of images. DESIGN, SETTING, AND PARTICIPANTS: Photographs of 12 ethnically diverse models (black, white, and Asian) were simulated to have strabismus from esotropia of 21 prism diopters (∆) to exotropia of 21∆. From July 1, 2007, to October, 1, 2008, images were presented to 120 non-health care professionals aged 21 years or older from the general community in Boston, Massachusetts, who were asked whether strabismus was present. Analysis was conducted from November 1, 2008, to March 31, 2009. MAIN OUTCOMES AND MEASURES: The threshold angle for detecting strabismus to enable 70% of lay observers to make a positive determination whether strabismus is present. RESULTS: In white and black models, the threshold allowing a 70% positive detection rate was higher for esotropia than for exotropia (P < .001 for both). For white models, the threshold was 23.2∆ (95% CI, 21.0∆ to 26.5∆) for esotropia and 13.5∆ (95% CI, 12.5∆ to 14.6∆) for exotropia. For black models, the threshold was 20.8∆ (95% CI, 19.2∆ to 22.2∆) for esotropia and 16.3∆ (95% CI, 15.5∆ to 17.2∆) for exotropia. Asian models showed an opposite trend, with the threshold allowing a 70% positive detection rate for esotropia (14.3∆; 95% CI, 13.2∆ to 15.7∆) being lower than that for exotropia (20.9∆; 95% CI, 18.0∆ to 24.6∆) (P < .001). CONCLUSIONS AND RELEVANCE: Esotropia was easier for lay observers to detect than exotropia in Asian models, and exotropia was easier to detect than esotropia in white and black models. This information should be considered when managing patients who have concerns about the social significance of their strabismus. Future studies should include diverse individuals and make an effort to account for individual factors that may alter the perception of strabismus.

IMPORTANCE: Asymmetric horizontal strabismus surgery is often performed to correct primary gaze alignment without considering the symptoms that may result from misalignment in the patient's side gaze. Surgical choices influence alignment in side gaze and may contribute to functional and social deficits. OBJECTIVE: To identify the surgical procedures associated with changes of alignment in side gaze to help inform surgical planning for patients with horizontal strabismus. DESIGN, SETTING, AND PARTICIPANTS: The medical records of 1081 horizontal strabismus surgical procedures that were performed at Boston Children's Hospital during a 2-year period were retrospectively reviewed. Only records with strabismus measurements recorded in the right and left gaze before and after surgery were included. Data analysis was conducted from September 1, 2012, through June 7, 2015. MAIN OUTCOMES AND MEASURES: Change in comitance (CIC), determined by measuring the horizontal comitance (the difference between right- and left-gaze strabismus measurements) before and after surgery. RESULTS: The review identified 569 patients who met the inclusion criteria. Of the 491 patients with comitant preoperative alignment, 59 developed postoperative incomitance, of whom 53 (89.9%) had asymmetric surgery. Of the 78 patients with incomitant preoperative alignment, 36 patients' (46.2%) deviation had improved to comitance after surgery; 32 (88.9%) of these patients had asymmetric surgery. Asymmetric 2-muscle surgery had a median CIC of 4.0 while symmetric 2-muscle surgery had a median CIC of 1.5 (difference in CIC, 2.5; 95% CI, 2.0-3.0; P < .001). A CIC of 25 prism diopters or more was observed in 6 patients who underwent asymmetric surgery (0 with symmetric surgery). New postoperative incomitance was symptomatic in at least 17 patients (28.8%). CONCLUSIONS AND RELEVANCE: Asymmetric strabismus surgery can treat incomitant deviations, but it can also create symptomatic incomitant deviations in patients who were previously comitant. Surgical planning should include consideration of the potential for CIC, including the potential for unsatisfactory appearance in side gaze. Patients with binocular vision will be sensitive to diplopia in any gaze direction; in such cases, the consequences of asymmetric surgery should be considered with particular care.

PURPOSE: To present a goal-determined methodology for monitoring outcomes after surgery for exotropia. METHODS: The goal-determined metric required surgeons to rank four possible goals preoperatively: (1) binocular potential, (2) restoration of eye contact, (3) diplopia control; and (4) torticollis management. Potential preoperative risk factors were noted. Goal-specific outcomes criteria were applied to the latest sensory-motor examination, 2-6 months after surgery. The medical records of patients who underwent surgery from 2007 to 2012 were retrospectively reviewed with respect to the goal-directed metric. RESULTS: A total of 852 patients were evaluated in the study period: 411 for restoration of eye contact; 347 for binocular potential; 78 for diplopia resolution; and16 for torticollis management. Excellent (62%) or good (16%) outcomes were achieved in 78%. Procedures to resolve diplopia (OR, 6.56; 95% CI, 3.39-12.68) and to restore eye contact (OR, 3.74; 95% CI, 2.65-5.29) were more likely to result in excellent outcomes than procedures to improve binocular potential. Simultaneous surgery for dissociated vertical deviation (OR, 0.38; 95% CI, 0.16-0.92) and preoperative near deviation ≥50(Δ) (OR, 0.27; 95% CI, 0.17-0.42) limited likelihood of an excellent outcome. Outcomes monitored by simultaneous rather than alternate prism and cover test were more likely graded excellent (OR, 5.16; 95% CI, 3.50-7.62). Applying motor criteria from the binocular potential goal to the entire cohort diminished putative outcomes (P < 0.001). CONCLUSIONS: Goal-determined metric monitoring outcomes of exotropia surgery provides outcomes germane to the reason for intervention, enables analysis of risk factors affecting outcomes, and facilitates reporting on heterogeneous populations.