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We compared sensitivity to first-order versus second-order local motion in patients treated for dense central congenital cataracts in one or both eyes. Amplitude modulation thresholds were measured for discriminating the direction of motion of luminance-modulated (first-order) and contrast modulated (second-order) horizontal sine-wave gratings. Early visual deprivation, whether monocular or binocular, caused losses in sensitivity to both first- and second-order motion, with greater losses for second-order motion than for first-order motion. These findings are consistent with the hypothesis that the two types of motion are processed by different mechanisms and suggest that those mechanisms are differentially sensitive to early visual input.

Unlike most objects, faces are processed holistically: They are processed as a whole rather than as a collection of independent features. We examined the role of early visual experience in the development of this type of processing of faces by using the composite-face task, a measure of holistic processing, to test patients deprived of visual experience during infancy. Visually normal control subjects showed the expected composite-face effect: They had difficulty perceiving that the top halves of two faces were the same when the top halves were aligned with different bottom halves. Performance improved when holistic processing was disrupted by misaligning the top and bottom halves. Deprived patients, in contrast, showed no evidence of holistic processing, and in fact performed significantly better than control subjects when top and bottom halves were aligned. These findings suggest that early visual experience is necessary to set up or maintain the neural substrate that leads to holistic processing of faces.

Adult expertise in face processing is mediated largely by neural networks in the right hemisphere. Here we evaluate the contribution of early visual input in establishing this neural substrate. We compared visually normal individuals to patients for whom visual input had been restricted mainly to one hemisphere during infancy. We show that early deprivation of visual input to the right hemisphere severely impairs the development of expert face processing, whereas deprivation restricted mainly to the left hemisphere does not. Our results indicate that the neural circuitry responsible for adults' face expertise is not pre-specified, but requires early visual experience. However, the two hemispheres are not equipotent: only the right hemisphere is capable of using the early input to develop expertise at face processing.

Objective: To evaluate the experiences, attitudes, and perceptions of the caregivers of children with cataracts who were visually rehabilitated with contact lenses., Participants: One hundred twenty-three caregivers of children <8.1 years old treated for unilateral and bilateral cataracts at one pediatric hospital., Design: Survey by questionnaire., Intervention: Primary caregivers were asked to complete an anonymous questionnaire., Main Outcome Measures: Caregiver responses to questions assessing background and demographic and clinical information, as well as perceptions, attitudes, levels of compliance, and anxiety with respect to treatment, were reviewed. Caregivers were also asked to choose between aphakic rehabilitation with contact lenses, aphakic glasses, or intraocular lenses, given various hypothetical scenarios differing in regard to their final visual prognosis, risks of treatment complications, and cost., Results: The response rate was 82.9%. Absolute average stress levels for contact lens use were 1.36 +/- 1.79 and 0.79 +/- 1.48 (scale, 0-5) for insertion and removal, respectively, compared with 4.03 +/- 1.64 and 2.40 +/- 1.92 for cataract surgery and patching therapy, respectively. Although average paired initial resistance to treatment (RT) levels for contact lens insertion and removal on a scale of 0 to 3 were high (2.09 +/- 1.15) and moderate (1.63 +/- 1.20), respectively, final RT levels were significantly lower (1.09 +/- 1.14 and 0.66 +/- 1.07, respectively; P < 0.0001). The vast majority of caregivers chose contact lens use in hypothetical scenarios that depicted realistic expectations for other forms of aphakic rehabilitation., Conclusions: In our study, contact lenses seemed to be well tolerated by most patients, as assessed by caregivers. Although initial resistance to contact lens use is high, this decreases with time. Relative to other events in the treatment of pediatric cataracts, contact lens use is not a major stressor for most caregivers and patients. This study supports the notion that contact lenses should continue to receive serious consideration as a treatment option for pediatric cataracts.

To compare the effects of early monocular versus early binocular deprivation on the perception of global form, we assessed sensitivity to global concentric structure in Glass patterns with varying ratios of paired signal dots to noise dots. Children who had been deprived by dense congenital cataracts in one (n=10) or both (n=8) eyes performed significantly worse than comparably aged children without eye problems. Consistent with previous results on sensitivity to global motion [Vision Research 42 (2002) 169], thresholds in the deprived eyes were significantly better after monocular deprivation than after binocular deprivation of comparable duration, even when there had been little patching of the nondeprived eye after monocular deprivation. Together, the results indicate that the competitive interactions between a deprived and nondeprived eye evident in the primary visual cortex can co-occur with complementary interactions in extrastriate cortex that enable a relative sparing of some visual functions after early monocular deprivation.

We used random-dot kinematograms to compare the effects of early monocular versus early binocular deprivation on the development of the perception of the direction of global motion. Patients had been visually deprived by a cataract in one or both eyes from birth or later after a history of normal visual experience. The discrimination of direction of global motion was significantly impaired after early visual deprivation. Surprisingly, impairments were significantly worse after early binocular deprivation than after early monocular deprivation, and the sensitive period was very short. The unexpectedly good results after monocular deprivation suggest that the higher centers involved in the integration of global motion profit from input to the nondeprived eye. These findings suggest that beyond the primary visual cortex, competitive interactions between the eyes can give way to collaborative interactions that enable a relative sparing of some visual functions after monocular deprivation.

This article examines the effects of visual input on the development of attention by comparing normal children to children, all more than 8 years old, who had been treated for bilateral congenital cataracts during infancy. In Experiment 1, patients pushed a button as soon as they detected a target that appeared 100, 400, or 800 msec after a central cue. The cue either validly cued the upcoming location or invalidly cued the wrong location. Patients (n = 16) performed normally at the 100 msec and 400 msec stimulus onset asynchrony (SOA). However, when the cue preceded the target by the 800 msec SOA, patients' reaction times were not affected by the validity of the cue, especially when deprivation had extended past 4 months of age. In Experiment 2, patients indicated which of two shapes appeared in the periphery 400 msec after a central cue, with those shapes surrounded by compatible or incompatible distractors. Patients (n = 15) differed from age-matched controls in (a) being slowed more by incompatible distractors on invalid trials, and (b) tending to show a larger than normal effect of the validity of the cue preceding targets in the upper visual field. Together, these findings suggest that the normal development of attention is influenced by early visual experience.

Using the method of limits, we measured spatial and temporal vision in 15 patients, aged 4-28 years, who had been monocularly deprived of patterned visual input during infancy by a dense cataract. All patients showed losses in both spatial and temporal vision, with greater losses in spatial than in temporal vision. Losses were smaller when there had been more patching of the non-deprived eye. The results indicate that visual deprivation has smaller effects on the neural mechanisms mediating temporal vision than on those mediating spatial vision.

Visual acuity was assessed in 28 human infants who had been deprived of all patterned visual input by cataracts in one or both eyes until they were treated at 1 week to 9 months of age. Immediately after treatment, acuity was no better than that of normal newborns. Acuity improved significantly over the next month, with some improvement apparent after as little as 1 hour of visual input. Unlike findings at older ages, the pattern of results was the same for eyes treated for monocular and for binocular deprivation. The results indicate that patterned visual input is necessary for the postnatal improvement of human visual acuity and that the onset of such input initiates rapid functional development.

Using the method of limits, we measured spatial and temporal vision in 13 children who had been deprived of patterned visual input during infancy until they were treated for dense central cataracts in both eyes. Spatial vision was assessed with vertical sine-wave gratings, and temporal vision was assessed with an unpatterned luminance field sinusoidally modulated over time. Under these testing conditions, spatial contrast sensitivity at low and medium spatial frequencies (0.33-2 c deg-1) was within normal limits, but sensitivity at higher spatial frequencies and grating acuity were reduced on average by 1.3 and 0.5 log units, respectively. Temporal vision was affected less severely, with losses in sensitivity only for low temporal frequencies (5 and 10 Hz), which averaged 0.4 log units. Thus, spatial and temporal vision are likely mediated by different neural mechanisms, that are differentially affected by deprivation.

Purpose: We measured the extent of the monocular visual fields of children deprived of normal visual experience and examined the influence of the timing and duration of deprivation, of whether deprivation was monocular or binocular, of having patched the fellow eye, and of optical factors., Methods: The Goldmann perimeter and a 6.4' stimulus of either 31.8 cd/m2 (target 12e) or of 318 cd/m2 (target 14e) were used to test 44 children treated for a dense and central cataract in one (n = 25) or both (n = 31) eyes that developed before 6 years of age. Then, the influence of optical factors was assessed in two adults treated for a late-onset, unilateral cataract and in two children treated for unilateral congenital cataract., Results: Compared with age norms or the normal fellow eye, all children treated for cataract showed a restricted field, especially temporally, even when deprivation began as late as 6 years of age and lasted less than 6 months. The restrictions were larger than those shown by the adults who developed cataracts. The restrictions were larger after longer deprivation and monocular deprivation than after binocular deprivation. However, children who regularly patched the fellow nondeprived eye and, therefore, experienced less interocular competition, exhibited smaller restrictions temporally. Neither visual acuity nor optical factors could account for all of the restrictions in the deprived children., Conclusions: The development of the visual field is vulnerable to the effects of deprivation, especially to unilateral deprivation and to long deprivation. The losses likely reflect alterations in the visual pathways subserving peripheral vision.

Purpose: To study the development of grating acuity in children treated for dense congenital unilateral or bilateral cataract and to examine how variations in treatment affect grating acuity during early childhood., Methods: The authors used optokinetic nystagmus (OKN), preferential looking (PL), or both to measure the grating acuity of children treated for congenital cataract in one eye (n = 63) or both eyes (n = 77) whenever possible from the time of treatment until 3 years of age. At each age, the authors compared patients' monocular acuity to that of children with no history of eye disorders., Results: The OKN acuity of treated eyes did not improve with age and was abnormal by 12 months of age. In contrast, PL acuity improved with age, and acuity of most treated eyes was not outside normal limits until 24 to 30 months of age. Nonetheless, at 12 months and at 3 years of age, PL acuity correlated significantly with age at treatment in children who had bilateral cataract. In children who had unilateral cataract, PL acuity correlated significantly with the number of hours per day the good eye had been patched since treatment. Children whose good eye was patched fewer than 3 hours per day did significantly worse than children treated at a comparable age for bilateral congenital cataract. However, children whose good eye was patched at least 3 hours per day had PL acuities similar to those of children treated at a comparable age for bilateral congenital cataract., Conclusions: Children treated for congenital cataract show deficits in grating acuity, with the deficit apparent earlier in OKN acuity than in PL acuity. At least by 1 year of age, visual development has begun to be influenced by the age at treatment and, in children treated for unilateral cataract, by patching of the good eye.

Purpose: To determine if form-deprived aphakes, like normal infants, show especially poor sensitivity in the nasal visual field. The purpose of this article was also to examine the influence on their peripheral sensitivity of the timing and duration of deprivation, of whether deprivation was monocular or binocular, and of having patched the fellow nondeprived eye., Methods: Static perimetry was used to measure intensity thresholds at 20 degrees in the nasal visual field and at 30 degrees in the temporal visual field in normal subjects (n = 20 7-year-old children, 20 8-year-old children, 12 9-year-old children, and 20 adults) and in 46 children treated for a dense and central cataract in one (n = 21) or both (n = 25) eyes. The deprivation began either at birth or after a normal early history, and the duration of deprivation varied widely among patients. Also tested were two adults who had been treated promptly for unilateral cataracts that had developed after the age of 40 years., Results: In normal subjects, sensitivity was slightly higher at 20 degrees nasally than at 30 degrees temporally, with no developmental changes in sensitivity at either location. The deprived eyes of the children had losses in sensitivity at both locations but only children treated for unilateral congenital cataract had larger losses at 20 degrees nasally than at 30 degrees temporally. There were no significant effects on their sensitivity of the duration of deprivation or, in children treated for unilateral cataract, of patching of the nondeprived eye. In contrast, the two patients in whom cataracts did not develop until adulthood had normal sensitivity., Conclusions: Pattern deprivation interferes with the development of peripheral sensitivity at both 30 degrees temporally and 20 degrees nasally. Nasal sensitivity, which is slow to mature, is affected more by early monocular deprivation than by early binocular deprivation. The results are consistent with the hypothesis that unfair interocular competition during early infancy especially affects visual functions that are slow to mature.

Purpose: The authors determined whether stereopsis can be demonstrated in children treated for congenital cataract after compensating for their amblyopia and strabismus., Methods: A custom-made set of large stereograms was used to compensate for amblyopia and presented in a synoptophore to facilitate motor fusion. Each pair of stereograms contained five wide vertical bars of high contrast, of which two or three were in crossed disparity. The authors aligned the stimuli in the synoptophore, then decreased the disparity until the child could no longer identify which bars appeared to be "in front.", Results: In normal children (n = 25), stereo acuity on this test (Tytla-Lewis-Maurer-Brent [TLMB] test) correlated well with the Titmus and Randot results within the ranges measured by those tests. Seven children in whom a traumatic cataract had developed after 6 yr of age (four with no clinical stereopsis) had TLMB test stereo acuities ranging from 225 to 28 arc-sec. Of 30 children treated for congenital cataract with no clinical stereopsis, 5 regularly achieved a TLMB stereo acuity of up to 225 arc-sec, and 2 with Titmus stereo acuities up to 200 arc-sec, each had a TLMB stereo acuity of 112 arc-sec. These seven congenital cases (two unilateral and five bilateral) with measurable TLMB acuities are among those with the shortest deprivation, the highest minimum resolvable acuity, and the highest contrast sensitivity., Conclusions: By compensating for amblyopia and strabismus, stereopsis can be demonstrated in some form-deprived amblyopic patients.

Purpose: The authors examined linear acuity and contrast sensitivity in the "good" (fellow) eye of children treated for unilateral congenital cataract to determine (1) whether there were subtle deficits like those described for the good eye of patients with strabismic amblyopia and (2) whether any deficits were related to the degree to which the good eye had been patched., Methods: The authors tested patients treated for unilateral congenital cataract who had a well-documented history of patching. The good eye was physically normal with minimal refractive error. The measures were linear acuity at far (n = 15) and contrast sensitivity (n = 9)., Results: Compared with age-matched control subjects, the good eyes of patients had subtle deficits in linear acuity and in contrast sensitivity at high spatial frequencies. These deficits occurred even in eyes that had received minimal patching, and their severity was not related systematically to the duration of patching, which varied widely across the group., Conclusion: The visual sensitivity of the good eye of children treated for unilateral congenital cataract is, on average, slightly reduced, even in cases of minimal patching. Consequently, any deficits discovered after aggressive patching may not have been caused by occlusion amblyopia.

Fifty-two cases of developmental cataracts extracted using the pars plicata lensectomy/vitrectomy technique were reviewed. Eyes with additional ocular anomaly other than microphthalmos were not included. No early complications were detected in a postoperative period ranging from 1.5 to 7 years with a median of 4 years, and late complications were limited to secondary membranes occurring in small eyes. Since secondary membranes occurred only in eyes in which the axial length was less than or equal to 17.4 mm and the corneal diameter was less than or equal to 9.5 mm, we suggest that eyes that are small by the absolute dimensions cited here are at greater risk of developing secondary membranes postoperatively. Small eyes by absolute dimensions should be distinguished from microphthalmic eyes, since the relative term microphthalmic is less predictive of risk of complication than are absolute dimensions. Linear Snellen acuity in 15 patients capable of response ranged as follows: 20/20-20/80 with a median of 20/40 in eyes with partial bilateral cataracts; 20/25-20/80 with a median of 20/50 in eyes with complete bilateral cataracts; 20/30-20/400 with a median of 20/200 in eyes with unilateral partial cataracts; and 20/60-CF with a median of 20/400 in eyes with complete unilateral cataracts. Mean patient ages at surgery were 3 months for those with bilateral complete cataracts, 5 months for those with unilateral complete cataracts, 18 months for those with bilateral partial cataracts, and 25 months for those with unilateral partial cataracts. The earliest possible removal of visually significant opacities must be combined with aggressive postoperative visual rehabilitation to obtain the best possible visual outcome.

The vision of cats which were monocularly deprived during early infancy, of kittens, and of young human infants shares two limitations: detection in the nasal visual field is far poorer than detection in the temporal visual field, and optokinetic nystagmus (OKN) is difficult to elicit when a pattern moves nasally to temporally. Here we report similar limitations on the vision of children who had a dense central cataract in one eye during early infancy. Extensive static perimetry with one of these children whose visual acuity was good in both eyes revealed that her threshold for detection all along the horizontal meridian was higher in her aphakic than in her normal eye, with this difference much more pronounced in the nasal visual field than in the temporal visual field. Three children who developed cataracts after 6 months of age showed no such discrepancy between thresholds in the temporal and nasal fields. We tested the symmetry of OKN in 12 children treated for unilateral congenital cataract. In every test of an aphakic (n = 4) or normal eye (n = 12), OKN occurred significantly more often when stripes moved temporally to nasally than when they moved nasally to temporally. In contrast, no asymmetry was observed in any of 13 children treated for traumatic cataracts incurred after 3 years of age. We conclude that children treated for unilateral congenital cataract, like young human infants and monocularly deprived cats, show asymmetric OKN and relatively poor detection in the nasal visual field.

We measured three aspects of vision in children treated for unilateral congenital cataract: visual resolution, the symmetry of optokinetic nystagmus (OKN), and peripheral vision. Good visual resolution was achieved by children who had had the earliest treatment and who had had the normal eye patched close to 50% of the waking time throughout early childhood. All children treated for unilateral congenital cataract showed a marked asymmetry of OKN regardless of the age of treatment. One child with early treatment who could be tested with the Goldmann perimeter also showed especially poor sensitivity in the nasal visual field of her aphakic eye. We found no such deficits in the vision of children who had had normal visual experience during early infancy and then later developed cataracts in one or both eyes. The limitations observed in children treated for congenital cataract are similar to those reported in normal human infants, in normal kittens, and in cats which were visually deprived early in life.

Ten years ago we proposed that the limitations on young infants' vision might be caused by an immature Y-pathway through the cortex, while their abilities might be mediated by an X-pathway to the cortex and by Y- and/or W-pathways to the superior colliculus and pretectum (Maurer & Lewis, 1979). Although that explanation was too simple overall, it fits well with what is known about asymmetrical optokinetic nystagmus, viz. the difficulty in eliciting OKN to patterns moving from the nasal field toward the temporal field. In this paper, we describe the development of symmetrical OKN, its alteration by early deprivation from cataract, and its physiological basis. We then suggest that, for primates, an explanation based on projections through the magnocellular versus parvocellular layers of the lateral geniculate nucleus may be more appropriate than one based on X-, Y-, and W-cells.