Pediatric Ophthalmology

IMPORTANCE: Superior rectus transposition (SRT) with or without medial rectus recession (MRc) has been introduced as an alternative to MRc alone for treatment of esotropic Duane syndrome; however, the effectiveness of these procedures has not been compared previously. OBJECTIVE: To compare the safety and efficacy of MRc and SRT in treatment of Duane syndrome. DESIGN, SETTING, AND PARTICIPANTS: Retrospective medical record review of all patients with esotropic Duane syndrome who underwent surgical treatment from January 1, 2006, through December 31, 2012, in a multispecialty, hospital-based pediatric ophthalmology/adult strabismus practice at Boston Children's Hospital. Patients in the SRT group underwent SRT with or without MRc; those in the non-SRT group underwent unilateral or bilateral MRc. EXPOSURES: Surgical treatment of esotropic Duane syndrome. MAIN OUTCOMES AND MEASURES: Binocular alignment, ocular ductions, head position, stereopsis, and fundus torsion were recorded before surgery and at the 2-month and final postoperative visits. We also evaluated postoperative drift. RESULTS: The medical record review identified 36 patients who underwent 37 procedures, including 19 in the SRT group (13 SRT + MRc and 6 SRT alone) and 18 in the non-SRT group (11 unilateral MRc and 7 bilateral medial rectus resession). Mean MRc was smaller when performed with SRT (3.3 vs 5.3 mm; P = .004). Although the initial deviation was larger in the SRT group, both groups had a similar improvement in esotropia and head turn. Abduction improved by at least 1 unit in 15 of 19 patients in the SRT group (79%) vs 5 of 18 in the non-SRT group (28%). In 24 patients followed up for more than 6 months, mean esotropia decreased from 8.2 to 6.1 prism diopters (Δ) in the SRT group (n = 12) but increased from 7.2 to 10.9Δ in the non-SRT group (n = 12). CONCLUSIONS AND RELEVANCE: The combination of SRT and MRc was more effective than MRc or bilateral medial rectus resession at improving abduction while allowing for a smaller recession to align the eyes and eliminate a compensatory head posture. Although any surgery on the vertical rectus muscles should in theory increase the risk for vertical or torsional complications, to date this theory has not been borne out in our patients. Patients treated with SRT appear to have a reduced likelihood of long-term undercorrection. We therefore recommend SRT with adjustable MRc for treatment of Duane syndrome in patients with larger amounts of esotropia.

PURPOSE: To measure binocular interaction in amblyopes using a rapid and patient-friendly computer-based method, and to test the feasibility of the assessment in the clinic. METHODS: Binocular interaction was assessed in subjects with strabismic amblyopia (n = 7), anisometropic amblyopia (n = 6), strabismus without amblyopia (n = 15) and normal vision (n = 40). Binocular interaction was measured with a dichoptic phase matching task in which subjects matched the position of a binocular probe to the cyclopean perceived phase of a dichoptic pair of gratings whose contrast ratios were systematically varied. The resulting effective contrast ratio of the weak eye was taken as an indicator of interocular imbalance. Testing was performed in an ophthalmology clinic under 8 mins. We examined the relationships between our binocular interaction measure and standard clinical measures indicating abnormal binocularity such as interocular acuity difference and stereoacuity. The test-retest reliability of the testing method was also evaluated. RESULTS: Compared to normally-sighted controls, amblyopes exhibited significantly reduced effective contrast (∼20%) of the weak eye, suggesting a higher contrast requirement for the amblyopic eye compared to the fellow eye. We found that the effective contrast ratio of the weak eye covaried with standard clincal measures of binocular vision. Our results showed that there was a high correlation between the 1st and 2nd measurements (r = 0.94, p<0.001) but without any significant bias between the two. CONCLUSIONS: Our findings demonstrate that abnormal binocular interaction can be reliably captured by measuring the effective contrast ratio of the weak eye and quantitative assessment of binocular interaction is a quick and simple test that can be performed in the clinic. We believe that reliable and timely assessment of deficits in a binocular interaction may improve detection and treatment of amblyopia.

PURPOSE: To compare accuracy of intraocular lens (IOL) power calculation formulae in infantile eyes with primary IOL implantation. DESIGN: Comparative case series. METHODS: The Hoffer Q, Holladay 1, Holladay 2, Sanders-Retzlaff-Kraff (SRK) II, and Sanders-Retzlaff-Kraff theoretic (SRK/T) formulae were used to calculate predicted postoperative refraction for eyes that received primary IOL implantation in the Infant Aphakia Treatment Study. The protocol targeted postoperative hyperopia of +6.0 or +8.0 diopters (D). Eyes were excluded for invalid biometry, lack of refractive data at the specified postoperative visit, diagnosis of glaucoma or suspected glaucoma, or sulcus IOL placement. Actual refraction 1 month after surgery was converted to spherical equivalent and prediction error (predicted refraction - actual refraction) was calculated. Baseline characteristics were analyzed for effect on prediction error for each formula. The main outcome measure was absolute prediction error. RESULTS: Forty-three eyes were studied; mean axial length was 18.1 ± 1.1 mm (in 23 eyes, it was <18.0 mm). Average age at surgery was 2.5 ± 1.5 months. Holladay 1 showed the lowest median absolute prediction error (1.2 D); a paired comparison of medians showed clinically similar results using the Holladay 1 and SRK/T formulae (median difference, 0.3 D). Comparison of the mean absolute prediction error showed the lowest values using the SRK/T formula (1.4 ± 1.1 D), followed by the Holladay 1 formula (1.7 ± 1.3 D). Calculations with an optimized constant showed the lowest values and no significant difference between the Holladay 1 and SRK/T formulae (median difference, 0.3 D). Eyes with globe AL of less than 18 mm had the largest mean and median prediction error and absolute prediction error, regardless of the formula used. CONCLUSIONS: The Holladay 1 and SRK/T formulae gave equally good results and had the best predictive value for infant eyes.

Retinopathy of prematurity occurs because the retina of a preterm infant at birth is incompletely vascularized, and if the postnatal environment does not match the in utero environment that supported retinal development, the vessels and neural retina will not grow normally. Risk factors determined from many clinical studies and animal studies fall into 2 categories: prenatal factors and postnatal factors.

OBJECTIVE: To identify nutritional and weight gain limitations associated with retinopathy of prematurity (ROP) severity among very preterm newborns. PATIENTS AND METHODS: 1180 infants <28 weeks GA at birth with ROP examination results were grouped and analyzed by quartile of weekly total calorie, carbohydrate, protein, and lipid intake, as well as growth velocity between postnatal days 7 and 28 (adjusted for GA and birth weight Z-score). ROP was categorized by development of no, mild (

PURPOSE: To compare long-term ophthalmic outcomes in infants treated for unilateral coronal synostosis (UCS) by endoscopic strip craniectomy (ESC) and helmet therapy with those treated by fronto-orbital advancement (FOA). METHODS: Consecutive patients with UCS, uncomplicated by other suture synostosis, were identified by a retrospective review of medical records. Assessment of presence of amblyopia, cycloplegic refraction, strabismus, and strabismus surgical intervention at all visits was recorded. RESULTS: Between 2004 and 2010, 22 patients were treated by FOA (mean follow-up, 21.5 months) and 21 patients with ESC and helmet therapy (mean follow-up, 23.5 months). The mean aniso-astigmatism was equal; however, the SD was greater for those treated by FOA (P < 0.05). A more severe pattern of strabismus developed in those treated by FOA (P < 0.0001). Those treated by FOA were more likely to have amblyopia (P = 0.0015) and to undergo surgical correction of their strabismus (odds ratio, 6.3:1). CONCLUSIONS: Children with UCS treated with ESC and helmeting had less severe overelevation in adduction, amblyopia, extremes of astigmatism, and less need for strabismus surgery than those treated by FOA. Although the reason for these more favorable outcomes remains uncertain, we speculate that the earlier timing of ESC or differences in the anatomical changes resulting from the two procedures may play a role.

Although retinopathy of prematurity (ROP) is clinically characterized by abnormal retinal vessels at the posterior pole of the eye, it is also commonly characterized by vascular abnormalities in the anterior segment, visual dysfunction which is based in retinal dysfunction, and, most commonly of all, arrested eye growth and high refractive error, particularly (and paradoxically) myopia. The oxygen-induced retinopathy rat model of ROP presents neurovascular outcomes similar to the human disease, although it is not yet known if the "ROP rat" also models the small-eyed myopia characteristic of ROP. In this study, magnetic resonance images (MRIs) of albino (Sprague-Dawley) and pigmented (Long-Evans) ROP rat eyes, and age- and strain-matched room-air-reared (RAR) controls, were examined. The positions and curvatures of the various optical media were measured and the refractive state (℞) of each eye estimated based on a previously published model. Even in adulthood (postnatal day 50), Sprague-Dawley and Long-Evans ROP rats were significantly myopic compared to strain-matched controls. The myopia in the Long-Evans ROP rats was more severe than in the Sprague-Dawley ROP rats, which also had significantly shorter axial lengths. These data reveal the ROP rat to be a novel and potentially informative approach to investigating physiological mechanisms in myopia in general and the myopia peculiar to ROP in particular.

PURPOSE: Retinopathy of prematurity (ROP) is a leading cause of blindness in children and is, in its most severe form, characterized by uncontrolled growth of vision-threatening pathologic vessels. Propranolol, a nonselective β-adrenergic receptor blocker, was reported to protect against pathologic retinal neovascularization in a mouse model of oxygen-induced retinopathy (OIR). Based on this single animal study using nonstandard evaluation of retinopathy, clinical trials are currently ongoing to evaluate propranolol treatment in stage 2 ROP patients who tend to experience spontaneous disease regression and are at low risk of blindness. Because these ROP patients are vulnerable premature infants who are still in a fragile state of incomplete development, the efficacy of propranolol treatment in retinopathy needs to be evaluated thoroughly in preclinical animal models of retinopathy and potential benefits weighed against potential adverse effects. METHODS: Retinopathy was induced by exposing neonatal mice to 75% oxygen from postnatal day (P) 7 to P12. Three routes of propranolol treatment were assessed from P12 to P16: oral gavage, intraperitoneal injection, or subcutaneous injection, with doses varying between 2 and 60 mg/kg/day. At P17, retinal flatmounts were stained with isolectin and quantified with a standard protocol to measure vasoobliteration and pathologic neovascularization. Retinal gene expression was analyzed with qRT-PCR using RNA isolated from retinas of control and propranolol-treated pups. RESULTS: None of the treatment approaches at any dose of propranolol (up to 60 mg/kg/day) were effective in preventing the development of retinopathy in a mouse model of OIR, evaluated using standard techniques. Propranolol treatment also did not change retinal expression of angiogenic factors including vascular endothelial growth factor. CONCLUSIONS: Propranolol treatment via three routes and up to 30 times the standard human dose failed to suppress retinopathy development in mice. These data bring into question whether propranolol through inhibition of β-adrenergic receptors is an appropriate therapeutic approach for treating ROP.

PURPOSE: To describe the incidence of associated infection, respiratory compromise, apparent intranasal cyst, as well as sex, laterality, and age at presentation in 64 infants with dacryocystocele and to assess characteristics associated with successful interventions. METHODS: A retrospective chart review of all patients with dacryocystocele seen at Children's Hospital Boston between 1996 and 2010 was performed. Inclusion criteria were accuracy of diagnosis, treatment, and follow-up at our institution. Interventions were divided into 3 categories: procedures that did not require general anesthesia; simple procedures requiring general anesthesia, such as nasolacrimal probing with or without stent or balloon dilation; and more complex procedures under general anesthesia, specifically, those aided by intranasal endoscopy. RESULTS: Of the 90 identified patients, 64 met inclusion criteria. The majority of patients were female (63%) and had unilateral involvement (77%). More than one-half of all patients were successfully treated without anesthesia; however, patients presenting with infection were more likely to be treated with a simple procedure under general anesthesia. All patients treated endoscopically had intranasal cysts. Age, sex, and infection did not predict the use of intranasal endoscopy. Bilaterality of dacryocystocele was associated with the use of an endoscopic approach. CONCLUSIONS: Many infants with dacryocystocoele can be successfully treated without general anesthesia. The incidence of occult intranasal cyst among those treated without endoscopy remains unknown. Patients who were treated under general anesthesia but without the use of nasal endoscopy were more likely to have an infected system, but the clinical significance of this association is not clear.

OBJECTIVE: To assess WINROP (https://winrop.com), an algorithm using postnatal weight measurements, as a tool for the prediction of retinopathy of prematurity (ROP) in a large geographically and racially diverse study population. METHODS: WINROP analysis was performed retrospectively on conventionally at-risk infants from 10 neonatal intensive careunits.Weight measurements were entered into WINROP, which signals an alarm for an abnormal weight gain rate. Infants were classified into categories of no alarm (unlikely to develop type 1ROP)and alarm (at risk for developing type 1ROP).Use of WINROP requires that an infant has (1) gestational age less than 32 weeks at birth, (2) weekly weight measurements,(3) physiologic weight gain,and(4)absence of other pathologic retinal vascular disease. RESULTS: A total of 1706 infants with a median gestational age of 28 weeks (range, 22-31 weeks) and median birth weight of 1016 g (range, 378-2240 g) were included in the study analysis. An alarm occurred in 1101 infants (64.5%), with a median time from birth to alarm of 3 weeks (range, 0-12 weeks) and from alarm to treatment of 8 weeks (range, 1 day to 22 weeks). The sensitivity of WINROP was 98.6% and the negative predictive value was 99.7%. Two infants with type 1 ROP requiring treatment after 40 weeks' postmenstrual age did not receive an alarm. CONCLUSION: The WINROP system is a useful adjunct for ROP screening that identifies high-risk infants early to optimize care and potentially reduce the overall number of diagnostic ROP examinations.

OBJECTIVE: To report the accuracy of intraocular lens (IOL) power calculations and the early refractive status in pseudophakic eyes of infants in the Infant Aphakia Treatment Study. METHODS: Eyes randomized to receive primary IOL implantation were targeted for a postoperative refraction of +8.0 diopters (D) for infants 28 to 48 days old at surgery and +6.0 D for those 49 days or older to younger than 7 months at surgery using the Holladay 1 formula. Refraction 1 month after surgery was converted to spherical equivalent, and prediction error (PE; defined as the calculated refraction minus the actual refraction) and absolute PE were calculated. Baseline eye and surgery characteristics and A-scan quality were analyzed to compare their effect on PE. MAIN OUTCOME MEASURES: Prediction error. RESULTS: Fifty-six eyes underwent primary IOL implantation; 7 were excluded for lack of postoperative refraction (n = 5) or incorrect technique in refraction (n = 1) or biometry (n = 1). Overall mean (SD) absolute PE was 1.8 (1.3) D and mean (SD) PE was +1.0 (2.0) D. Absolute PE was less than 1 D in 41% of eyes but greater than 2 D in 41% of eyes. Mean IOL power implanted was 29.9 D (range, 11.5-40.0 D); most eyes (88%) implanted with an IOL of 30.0 D or greater had less postoperative hyperopia than planned. Multivariate analysis revealed that only short axial length (<18 mm) was significant for higher PE. CONCLUSIONS: Short axial length correlates with higher PE after IOL placement in infants. Less hyperopia than anticipated occurs with axial lengths of less than 18 mm or high-power IOLs. Application to Clinical Practice Quality A-scans are essential and higher PE is common, with a tendency for less hyperopia than expected. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00212134.

PURPOSE: To report ocular injuries caused by airsoft guns in children. METHODS: A retrospective chart review of pediatric patients who sustained ocular injuries related to airsoft guns between November 2005 and December 2007. Place of trauma, presenting symptoms and signs, surgical interventions performed, and final visual outcome were reviewed. RESULTS: Thirty-two patients with a mean age of 8.8 ± 4.0 years (range: 1.5 to 18 years) were examined; 28 were boys (87.5%). Presenting visual acuity ranged from hand motions to 20/20 and could not be assessed in 2 patients. Hyphema was a common finding that was present in 24 cases, corneal abrasions were present in 10 cases, and raised intraocular pressure was present in 7 cases. Seven patients presented with traumatic cataract, and two had iridodialysis. Immediate surgical intervention was performed in 7 patients and 7 patients were scheduled for elective surgery. The patients presented after an average of 1.9 ± 1.9 days (range: 4 hours to 6 days) after the injury. Average follow-up was 18 days (range: 7 days to 5 months). Final visual acuity was 20/200 or worse in 5 patients, 20/40 or better in 23 patients, and could not be assessed in 2 cases. CONCLUSION: Airsoft guns can cause a variety of serious injuries, sometimes necessitating operative intervention. The long-term morbidity from some of these injuries is significant. Airsoft guns are capable of inflicting serious and permanent ocular damage.

The antiepileptic drug vigabatrin is known to cause retinal and visual dysfunction, particularly visual field defects, in some patients. Electroretinography (ERG) is used in an attempt to identify adverse effects of vigabatrin (VGB) in patients who are not candidates for conventional perimetry. We report data from 114 pediatric patients taking VGB referred for clinical evaluation; median age at test was 22.9 (2.4 to 266.1) months, and median duration of VGB use was 9.7 (0.3 to 140.7) months. Twenty-seven of them were tested longitudinally (3 to 12 ERG tests). ERG responses to full-field stimuli were recorded in scotopic and photopic conditions, and results were compared to responses from healthy control subjects. We found that abnormalities of photoreceptor and post-receptor ERG responses are frequent in these young patients. The most frequently abnormal scotopic parameter was post-receptor sensitivity, log σ, derived from the b-wave stimulus-response function; the most frequently abnormal photopic parameter was the implicit time of the OFF response (d-wave) to a long (150 ms) flash. Abnormal 30-Hz flicker response amplitude, previously reported to be a predictor of visual field loss, occurred infrequently. For the group as a whole, none of the ERG parameters changed significantly with increasing duration of VGB use. Four of the 27 patients tested longitudinally showed systematic worsening of log σ with duration of VGB use. In a subset of patients who underwent perimetry (N = 39), there was no significant association of any ERG parameter with visual field defects. We cannot determine whether the ERG abnormalities we found were due solely to the effects of VGB. We caution against over-reliance on the ERG to monitor pediatric patients for VGB toxicity and recommend further development of a reliable test of peripheral vision to supplant ERG testing.