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The effect of strabismus on a young child’s selection of a pJohns HA, Manny RE, Fern KD, Hu YS. Ophthalmic and PhysOptics 2005;25:400-7.

This article is an extension of several recent studies of thelar consequences of manifest strabismus. Reports on the socsequences of strabismus first appeared more than 50 years athe advent of digital imaging, our ability to study this issue hgreatly enhanced. The current study involved creating photimages of 15 children without strabismus who appeared ortSubjects were between 3 and 6 years of age and recruitfamilies of university faculty, staff, students, and others visUniversity of Houston College of Optometry. Both males andwere included, along with children of Caucasian, African Aand Hispanic descent. A separate group of 122 children betwe8 years of age who were not playmates or related to the 1graphed children were recruited to view the photographs. Therandomly arranged in a book showing two photographs ofchildren on each page, one unedited (orthotropic) and the ottally altered to show varying amounts of esotropia or exotrop

Overall, the results indicated that children in the 3- to 8-yearrange were not less likely (ie, no difference) to indicate a childdesirable playmate because of the presence of strabismus. H�2 analysis identified 23 children (11% of the cohort) in whommus appeared to influence their choice of playmate, but not nenegatively. There was no apparent influence of age, gendedirection or magnitude of the “strabismus.” While an earlier puby Paysse et al1 suggest that negative attitudes toward stremerge at around age 6 years, this study was conducted usingwould seem to demonstrate only that children prefer to pnonstrabismic dolls; it does not directly address the issue of prein the selection of human playmates.

The jury is still out. The authors acknowledge that the stand nonstrabismic children were randomly paired, potentiaducing a bias based on other factors unrelated to the strasuch as hairstyle, physical attractiveness, and so forth. Tlieve, however, that such influences would be irrelevant ifmus were a highly undesirable characteristic in a playmatthe authors attempted to obtain additional verbal corroborplaymate selection, this information could be determined insubjects—too few for a meaningful analysis.

References1. Paysse EA, Steele EA, McCreery B, Wilhelmus KM, Coats

of the emergence of negative attitudes toward strabismus.2001;5:361-6.

Comparing efficacies of 0.5% apraclonidine with 4% cocaindiagnosis of Horner Syndrome in pediatric patients. Chen PJT, Lu DW, Chen YC, Hsiao CH. Journal of Ocular PharmacoTherapeutics 2006;22:182-7.

This interesting study compared the use of cocaineapraclonidine 0.5% in the diagnosis of Horner syndrome in ppatients. Ten subjects ranging in age from 1 to 18 years werusing a crossover study design in which patients, usinapraclonidine or cocaine, were evaluated 1 week apart. Thon pupil size was measured using external photographyfollowing drop instillation.

All subjects had been diagnosed with “probable” Horner sbased on clinical findings of unilateral relative miosis, greatewith dilation lag, upper eyelid ptosis of 1 to 2 mm, and iris het

mia (six patients). Ophthalmologic examination included magnetic re

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onance imaging of the head and neck as well as urine screeninclinically indicated. A definitive etiology and underlying diagnestablished in only 4 of the 10 patients (40%).

All patients had a “positive” response to pharmacologic tesmean anisocoria (in mm) statistically increased ( p � 0.01)groups, but the anisocoria consistently reversed in the apracgroup. This finding is presumably due to the difference in mechaction of the two drugs. Cocaine works by inhibiting reunorepinephrine at the synaptic junction, whereas apracloni�-adrenergic agonist, relies on denervation super-sensitivitpostsynaptic �1-receptor in the pupil dilator muscle. This clinture would make apraclonidine particularly useful in thesetting, where judgment of pupil diameter, external photogrpupillography may be difficult or impossible to obtain. Whclonidine has been associated with somnolence and othersystemic side effects in children when used to treat glaucoauthors observed no complications in their study group. Conhyperemia was noted in only two cases.

A few caveats are in order. The number of subjects in thwas small, and half were over 5 years of age. Since apracrelies on denervation super-sensitivity, recent-onset Horntients may give false-negative results. Given the potentialtemic side effects in younger children, the drug is avoidetreatment of pediatric glaucoma. Nevertheless, becausedifficulties associated with storage and monitoring a cosubstance, such as cocaine, its short shelf-life, and relucsome parents to allow the testing, apraclonidine may proveexcellent alternative agent for the diagnosis of Horner syn

Central corneal thickness and corneal diameter in premafants. Kirwan C, O’Keefe M, Fitzsimon S. Acta OphthalmScandinavica 2005;83:751-3.

This succinct article essentially makes one point: centralthickness is significantly greater in premature infants thanterm infants. Several previous studies have identified thetance of corneal thickness as related to measurement of intpressure. Thinner corneas tend to generate lower intraocusure readings, at least when measured by applanation tonWhile it is known that corneas of full-term infants are thicin older children or adults, the results of ultrasound pachypremature infant corneas have not been previously reporte

As an adjunct to routine screening for retinopathy of prethe authors studied 70 eyes of 35 infants. They found a meanthickness of approximately 700 �m in infants 30 to 32 weeksceptional age, gradually decreasing to just over 560 �m byweeks postconceptional age ( p � 0.05). They also studied chcorneal diameter and noted a progressive increase in the meandiameter from approximately 8 mm at 30 to 32 weeks postconcage to just over 9.5 mm at 39 to 41 weeks postconceptional anormal corneal enlargement (about 40%) may help explain thtion in number of endothelial cells that is known to occur conc

To the extent that premature infants have hazy corneascharacteristics that might alter intraocular pressure readimportant. Based on these data, a scenario could theoreticonstructed in which a premature infant with somewhat thneas and typical haze might be incorrectly diagnosed withital glaucoma. While the authors acknowledge that the exacanism by which corneas become thinner during developunknown, they speculate that the concurrent thinning of the

s- and increase in its diameter with ocular growth suggest a “remod-

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Volume 10 Number 6 December 2006 Saunders 599

eling and stretching” of the collagen fibers as well as chacentral corneal hydration.

Magnetic resonance imaging of the effects of horizontaextraocular muscle surgery on pulley and globe positistability. Clark RA, Demer JL. Investigative OphthalmoloVisual Science 2006;47:188-94.

Purpose: Magnetic resonance imaging was used to dethe effect of recessions and resections on horizontal extmuscle (EOM) paths and globe position.

Methods: Four adults with horizontal strabismus underwtrast-enhanced, surface-coil MRI in central, secondary, andgazes, before and after horizontal EOM recessions and/or reEOM paths were determined from 2-mm-thickness, quasicoroby analysis of cross-sectional area centroids in a normalizedcentric coordinate system. Globe displacement was determmeasuring the apparent shift of the bony orbit in eccentric ga

Results: In all subjects, the antero-posterior positionshorizontal rectus pulleys shifted by less than 2 mm afterindistinguishable from zero within measurement precision.subjects who underwent medial rectus (MR) recession or repostoperative globe position was similar in central gaze, btranslation during vertical gaze shift changed markedly. Thno effect on globe translation in the subject who underwlateral rectus muscle resection.

Conclusions: Recessions and resections of horizontahave minimal effect on anteroposterior EOM pulley positiocause the pulley does not shift appreciably despite large altin the EOM insertion, the proximity of a recessed EOM to iwould be expected to introduce torsional and vertical actertiary gazes. Connective tissue dissection during MRmay destabilize the globe’s vertical translational stabilitthe orbit, potentially changing the effective pulling directhe rectus EOMs in vertical gazes. These changes maoblique muscle dysfunction. Lateral rectus muscle surgavoid globe destabilization.

Eye movement recordings as an effectiveness indicatortherapy in RPE65-deficient canines: implications for themotor system. Jacobs JB, Dell’Osso LF, Hertle RW, AclaBennett J. Investigative Ophthalmology and Visual Science2865-75.

Purpose: To perform ocular motility recordings of infantagmus (IN) in RPE65-deficient canines and to determinethey can be used as a motor indicator of restored retinal funinvestigate the effects of gene therapy.

Methods: Viral vectors were delivered by subretinal iTreated and untreated animals were comfortably suspendcustom-built sling and encouraged to fixate on distant tagaze angles varying between �15 degrees horizontally adegrees vertically. Ocular motility recordings were madetreatment, and 3 and 10 months after treatment, using twomethods: infrared reflection and high-speed video. The rrecordings from three untreated, four treated, and three pposttreatment dogs were analyzed for using the eXpandedmus Acuity Function (NAFX ), which yields an objective assof best potential visual acuity, based on the duration and repaccuracy of foveation and centralization.

Results: During fixation, the untreated dogs exhibiteamplitude, classic IN waveforms, including pendular and jerthe horizontal and the vertical planes, which prevented th

keeping the targets within the area centralis (the region of highe

Journal of AAPOS

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receptor density, spanning �3 degrees horizontally by �1.5vertically, analogous to the fovea). Some untreated dogs asmall-amplitude (0.5 to 1 deg), high-frequency (6 to 9 Hz) oscUnder the same conditions, successfully treated canines nexhibited clinically detectable IN. Their IN was converted tforms with very low amplitudes yielding higher NAFX valallowing target images to remain well within the area cenparticular note, uniocular treatment appeared to dampen tboth eyes. Behaviorally, the treated dogs were able tomore successfully through obstacles without inadvertent cotask which the untreated dogs were unable to do.

Conclusions: Gene therapy that successfully restoredfunction also reduced the accompanying IN to an extent thanot clinically detectable �90% of the time in many of thImprovement in IN, as quantified by the NAFX, is an objectivindicator of visual improvement due to gene therapy.

Effect of topical 1.25% povidone-iodine eyedrops used forlaxis of ophthalmia neonatorum on renal iodine excretthyroid-stimulating hormone level. Richter R, Below H, KKramer A, Muller C, Fusch C. Journal of Pediatrics 2006;14

This article describes the influence of topically appliepovidone-iodine solution on thyroid function in neonates. Ispective trial involving newborns at a university-affiliated hoGermany, 69 infants (37 males and 32 females) were randoreceive either 1% silver nitrate drops or 1.25% povidondrops within 60 minutes of delivery. The medications were pby the university pharmacy in single-use vials, which wereand labeled by a code. Exclusion criteria included mothknown thyroid disease, gestational age less than 37 weeks,postpartum urination, and parental refusal.

Baseline thyroid function was determined usingstimulating hormone (TSH) samples obtained from umbiliblood the day of birth and from capillary blood on day 5. Inurine samples were collected on days 1, 2, and 5 of life andiodide concentrations were measured. Comparison of thnitrate and povidone-iodine groups did not reveal significanences in any standard category (weight, height, gestatioApgar score, etc.) or thyroid status at the time of birth. Levelwere also equivalent at day 5. However, mean urinary iodcentration on day 2 was 14.5 �g/dL in the silver nitrate grou23.1 �g/dL in the povidone-iodine group ( p � 0.015). No infapovidone-iodine group exhibited external eye problems. Hone-third of infants in the silver nitrate group developed evidchemical conjunctivitis, which spontaneously resolved in a

Povidone-iodine has been shown to be an effective alter1% silver nitrate drops, topical erythromycin, or tetracycline ointhe prevention of ophthalmia neonatorum. Its principal advaeffectiveness against some viruses and Chlamydia trachomatisexcellent tolerability.1 However, there is a potential effect onfunction from absorption of the approximately 70 �g of iodine cin a drop of povidone-iodine solution. While urinary excretionin the urine increased significantly in these infants, serum TSwere unaffected. The authors conclude that a single administ1.25% povidone-iodine solution eyedrops in healthy newborn isafe, but recommend additional studies to determine potentialeffects in preterm infants.

References1. Isenberg, SJ, Apt, L, Wood, M. A controlled trial of povidon

as prophylaxis against ophthalmia neonatorum. N Engl J M

st 332:562-6.