Pediatric Ophthalmology

Hansen RM, Tavormina JL, Moskowitz A, Fulton AB. Effect of retinopathy of prematurity on scotopic spatial summation. Invest Ophthalmol Vis Sci 2014;55(5):3311-3.Abstract
PURPOSE: To evaluate scotopic retinal organization in retinopathy of prematurity (ROP) through a study of spatial summation. METHODS: Thresholds for a range of stimulus diameters (0.4°-10°) were measured using a two alternative, spatial, forced choice psychophysical procedure. The critical diameter (DCRIT) for complete summation was estimated in subjects with a history of severe ROP (N = 7) and mild ROP (N = 17). Subjects who were born preterm and never had ROP (N = 16) and term-born subjects (N = 7) were also tested. The subjects ranged in age from 9 to 17 (median 13.5) years. RESULTS: Critical diameter for complete spatial summation was significantly larger in ROP subjects than in subjects who never had ROP and in term-born control subjects. Critical diameter varied significantly with severity of ROP. CONCLUSIONS: The larger DCRIT values in ROP are consistent with altered organization of the post receptor retina. This may offer the ROP retina a strategy for achieving noise reduction and good dark-adapted visual sensitivity.
Engel MJ, Guyton DL, Hunter DG. Adjustable sutures in children. J AAPOS 2014;18(3):278-84.Abstract
Although adjustable sutures are considered a standard technique in adult strabismus surgery, most surgeons are hesitant to attempt the technique in children, who are believed to be unlikely to cooperate for postoperative assessment and adjustment. Interest in using adjustable sutures in pediatric patients has increased with the development of surgical techniques specific to infants and children. This workshop briefly reviews the literature supporting the use of adjustable sutures in children and presents the approaches currently used by three experienced strabismus surgeons.
West CE, Hunter DG. Displacement of optical centers in over-the-counter readers: a potential cause of diplopia. J AAPOS 2014;18(3):293-4.Abstract
Induced prism in spectacle lenses, which may result from inadvertent displacement of optical centers, may worsen an existing heterophoria or even cause diplopia, yet over-the-counter reading glasses (OTC readers) are not always assessed by clinicians when evaluating patients with diplopia or asthenopia. To gauge the magnitude of this potential problem, we used a focimeter and prescription aligner to assess the frequency and extent of clinically significant manufacturing variations in a random selection of 160 OTC readers. The optical centers were vertically displaced by ≥3 mm in 11%, with a maximum displacement of 7 mm in 1 pair. Average interpupillary distance was 64 mm (range, 58-74.5 mm), with interpupillary distance outside the normal range of 60-70 mm in 5%. Monocular pupillary distance was asymmetric by ≥5 mm in 4%. A 0.75 D power difference between lenses was measured in one pair of OTC readers. Some OTC readers have misaligned optical centers and other manufacturing defects that are of a magnitude sufficient to exacerbate a heterophoria and cause asthenopia or diplopia.
Wentworth BA, Freitas-Neto CA, Foster SC. Management of pediatric uveitis. F1000Prime Rep 2014;6:41.Abstract
Pediatric uveitis is a topic of special interest not only because of the unique diagnostic and therapeutic challenges but also because of the lifetime burden of vision loss if the problem is not adequately treated, as well as the economic and psychological toll on the family. Often, uveitis in children is discovered as part of a routine eye exam; this silent, insidious inflammation can be difficult to treat and can lead to further complications if not handled skillfully. Corticosteroids have long been the mainstay of therapy; however, the significant associated side effects mandate a corticosteroid-sparing therapeutic regimen in pursuit of remission. In this review, we cover the therapeutic options for pediatric uveitis, specifically focusing on the most common non-infectious varieties, juvenile idiopathic arthritis-associated uveitis and pars planitis.
Lundgren P, Kistner A, Andersson EM, Hansen Pupp I, Holmström G, Ley D, Niklasson A, Smith LEH, Wu C, Hellström A, Löfqvist C. Low birth weight is a risk factor for severe retinopathy of prematurity depending on gestational age. PLoS One 2014;9(10):e109460.Abstract
OBJECTIVE: To evaluate the impact of low birth weight as a risk factor for retinopathy of prematurity (ROP) that will require treatment in correlation with gestational age at birth (GA). STUDY DESIGN: In total, 2941 infants born <32 weeks GA were eligible from five cohorts of preterm infants previously collected for analysis in WINROP (Weight IGF-I Neonatal ROP) from the following locations: Sweden (EXPRESS) (n = 426), North America (n = 1772), Boston (n = 338), Lund (n = 52), and Gothenburg (n = 353). Data regarding GA at birth, birth weight (BW), gender, and need for ROP treatment were retrieved. Birth weight standard deviation scores (BWSDS) were calculated with Swedish as well as Canadian reference models. Small for gestational age (SGA) was defined as BWSDS less than -2.0 SDS using the Swedish reference and as BW below the 10th percentile using the Canadian reference charts. RESULTS: Univariate analysis showed that low GA (p<0.001), low BW (p<0.001), male gender (p<0.05), low BWSDSCanada (p<0.001), and SGACanada (p<0.01) were risk factors for ROP that will require treatment. In multivariable logistic regression analysis, low GA (p<0.0001), male gender (p<0.01 and p<0.05), and an interaction term of BWSDS*GA group (p<0.001), regardless of reference chart, were risk factors. Low BWSDS was less important as a risk factor in infants born at GA <26 weeks compared with infants born at GA ≥26 weeks calculated with both reference charts (BWSDSSweden, OR = 0.80 vs 0.56; and BWSDSCanada, OR = 0.72 vs 0.41). CONCLUSIONS: Low BWSDS as a risk factor for vision-threatening ROP is dependent on the infant's degree of immaturity. In more mature infants (GA ≥26 weeks), low BWSDS becomes a major risk factor for developing ROP that will require treatment. These results persist even when calculating BW deficit with different well-established approaches.
Yang S, MacKinnon S, Dagi LR, Hunter DG. Superior rectus transposition vs medial rectus recession for treatment of esotropic Duane syndrome. JAMA Ophthalmol 2014;132(6):669-75.Abstract
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.
Wan MJ, Adebona O, Benson LA, Gorman MP, Heidary G. Visual outcomes in pediatric optic neuritis. Am J Ophthalmol 2014;158(3):503-7.e2.Abstract
PURPOSE: To describe the visual outcomes of a large cohort of pediatric patients presenting to a tertiary care pediatric hospital with first-episode optic neuritis. DESIGN: Retrospective, observational cohort study. METHODS: In a tertiary care pediatric hospital, patients with first-episode optic neuritis and at least 3 months of follow-up over a 10-year period were assessed and followed-up in the ophthalmology department. The main outcome measures were visual acuity at 3 months and 1 year of follow-up, with analysis of risk factors for poor visual outcomes and the time course of visual recovery. RESULTS: Of the 59 pediatric patients with first-episode optic neuritis, 46 had at least 3 months of follow-up and 36 had at least 1 year of follow-up. The mean age was 12.6 years old; 72% were female, 41% had bilateral involvement, 52% had or developed an underlying diagnosis (39% multiple sclerosis, 7% acute disseminated encephalomyelitis, 7% neuromyelitis optica), and 91% received treatment (85% steroids, 7% multimodal). At 1 year, 81% were at least 20/20 and 89% were at least 20/40. A poor visual outcome at 1 year (<20/40) was associated with vision of <20/20 at 3 months (P = 0.041). Other clinical characteristics, including visual acuity at presentation, sex, bilateral involvement, optic nerve edema, and underlying diagnoses were not significantly associated with poor visual outcomes. CONCLUSIONS: In this cohort of pediatric patients with optic neuritis, the majority of patients regained normal visual acuity at 1 year, regardless of baseline clinical characteristics.
Kwon MY, Lu Z-L, Miller A, Kazlas M, Hunter DG, Bex PJ. Assessing binocular interaction in amblyopia and its clinical feasibility. PLoS One 2014;9(6):e100156.Abstract
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.
VanderVeen DK, Martin CR, Mehendale R, Allred EN, Dammann O, Leviton A, Leviton A. Early nutrition and weight gain in preterm newborns and the risk of retinopathy of prematurity. PLoS One 2013;8(5):e64325.Abstract
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 (
VanderVeen DK, Trivedi RH, Nizam A, Lynn MJ, Lambert SR, Lambert SR. Predictability of intraocular lens power calculation formulae in infantile eyes with unilateral congenital cataract: results from the Infant Aphakia Treatment Study. Am J Ophthalmol 2013;156(6):1252-1260.e2.Abstract
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.
Smith LE, Hard A-L, Hellström A. The biology of retinopathy of prematurity: how knowledge of pathogenesis guides treatment. Clin Perinatol 2013;40(2):201-14.Abstract
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.
MacKinnon S, Proctor MR, Rogers GF, Meara JG, Whitecross S, Dagi LR. Improving ophthalmic outcomes in children with unilateral coronal synostosis by treatment with endoscopic strip craniectomy and helmet therapy rather than fronto-orbital advancement. J AAPOS 2013;17(3):259-65.Abstract
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.
Chen J, Joyal J-S, Hatton CJ, Juan AM, Pei DT, Hurst CG, Xu D, Stahl A, Hellstrom A, Smith LEH. Propranolol inhibition of β-adrenergic receptor does not suppress pathologic neovascularization in oxygen-induced retinopathy. Invest Ophthalmol Vis Sci 2012;53(6):2968-77.Abstract
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.