Macular Morphologic and Microvascular Analysis in Pseudophakic Children with Previous Pediatric Cataract Using Optical Coherence Tomography Angiography.

INTRODUCTION: The macular morphologic and microvascular changes in children with pseudophakia after pediatric cataract surgery remain unknown. The aim of this study was to analyze macular morphologic and microvascular remodeling in children with pseudophakia after pediatric cataract surgery using optical coherence tomography angiography (OCTA). METHODS: Consecutive cases between December 1, 2018, and November 31, 2020 were recruited. Sixty-one participants (31 pseudophakic children and 30 healthy controls) met the inclusion criteria and were included for final analysis. OCTA was used to measure macular vascular density, the foveal avascular zone (FAZ), and macular thickness. The parameters were compared between pseudophakic and healthy eyes using binary logistic regression, with adjustment for the effect of refractive error, age, and axial length. RESULTS: Compared with normal eyes, a significantly reduced area of the FAZ (p = 0.042), increased superficial foveal vascular density (p = 0.033), and increased inner and outer foveal thickness (p = 0.034 and 0.029, respectively) were noted in pseudophakic eyes. The deep parafoveal vascular density was generally lower in eyes with cataracts (p ≤ 0.044). The inner foveal thickness was positively correlated with the superficial foveal vascular density (r = 0.889, p < 0.001) and negatively correlated with the area of the FAZ (r = -0.903, p < 0.001). The outer foveal thickness was positively correlated with the deep foveal vascular density (r = 0.399, p = 0.002). CONCLUSIONS: Morphological and microvascular remodeling in children with previous pediatric cataract indicates foveal underdevelopment. The underlying mechanism requires further investigation.

Learning to see after early and extended blindness: A scoping review.

Purpose: If an individual has been blind since birth due to a treatable eye condition, ocular treatment is urgent. Even a brief period of visual deprivation can alter the development of the visual system. The goal of our structured scoping review was to understand how we might better support children with delayed access to ocular treatment for blinding conditions. Method: We searched MEDLINE, Embase and Global Health for peer-reviewed publications that described the impact of early (within the first year) and extended (lasting at least 2 years) bilateral visual deprivation. Results: Of 551 reports independently screened by two authors, 42 studies met our inclusion criteria. Synthesizing extracted data revealed several trends. The data suggests persistent deficits in visual acuity, contrast sensitivity, global motion, and visual-motor integration, and suspected concerns for understanding complex objects and faces. There is evidence for resilience in color perception, understanding of simple shapes, discriminating between a face and non-face, and the perception of biological motion. There is currently insufficient data about specific (re)habilitation strategies to update low vision services, but there are several insights to guide future research in this domain. Conclusion: This summary will help guide the research and services provision to help children learn to see after early and extended blindness.

Contrast-balanced binocular treatment in children with deprivation amblyopia.

BACKGROUND: Children with deprivation amblyopia due to childhood cataract have been excluded from much of the emerging research into amblyopia treatment. An investigation was conducted to determine whether contrast-balanced binocular treatment - a strategy currently being explored for children with anisometropic and strabismic amblyopia - may be effective in children with deprivation amblyopia. METHODS: An unmasked, case-series design intended to assess proof of principle was employed. Eighteen children with deprivation amblyopia due to childhood cataracts (early bilateral n = 7, early unilateral n = 7, developmental n = 4), as well as 10 children with anisometropic (n = 8) or mixed anisometropic and strabismic amblyopia (n = 2) were prescribed one hour a day of treatment over a six-week period. Supervised treatment was available. Visual acuity, contrast sensitivity, global motion perception and interocular suppression were measured pre- and post-treatment. RESULTS: Visual acuity improvements occurred in the anisometropic/strabismic group (0.15 ± 0.05 logMAR, p = 0.014), but contrast sensitivity did not change. As a group, children with deprivation amblyopia had a smaller but statistically significant improvement in weaker eye visual acuity (0.09 ± 0.03 logMAR, p = 0.004), as well a significant improvement in weaker eye contrast sensitivity (p = 0.004). Subgroup analysis suggested that the children with early bilateral deprivation had the largest improvements, while children with early unilateral cataract did not improve. Interestingly, binocular contrast sensitivity also improved in children with early bilateral deprivation. Global motion perception improved for both subgroups with early visual deprivation, as well as children with anisometropic or mixed anisometropic/strabismic amblyopia. Interocular suppression improved for all subgroups except children with early unilateral deprivation. CONCLUSION: These data suggest that supervised contrast-balanced binocular treatment should be further investigated as a treatment option for children with deprivation amblyopia. However, for children with more severe deprivation amblyopia due to early unilateral cataracts, supplementary or alternative options should also be explored.

A rare case of persistent pupillary membrane: Case-based approach and management.

Persistent pupillary membranes (PPMs) are a common congenital anomaly seen in 95% of neonates. Extensive PPMs, occluding the visual axis and resulting in reduced visual acuity, are relatively uncommon. We describe a case of bilateral total PPM in a 36-year-old female who presented with complaints of blurred vision in both the eyes. Dense pupillary membranes obscuring the visual axis need early surgical treatment. It is essential that the lens status remains clear along the visual axis both before and after pupilloplasty.

Motion perception: a review of developmental changes and the role of early visual experience.

Significant controversies have arisen over the developmental trajectory for the perception of global motion. Studies diverge on the age at which it becomes adult-like, with estimates ranging from as young as 3 years to as old as 16. In this article, we review these apparently conflicting results and suggest a potentially unifying hypothesis that may also account for the contradictory literature in neurodevelopmental disorders, such as Autism Spectrum Disorder (ASD). We also discuss the extent to which patterned visual input during this period is necessary for the later development of motion perception. We conclude by addressing recent studies directly comparing different types of motion integration, both in typical and atypical development, and suggest areas ripe for future research.

Baseline characteristics of the infant aphakia treatment study population: predicting recognition acuity at 4.5 years of age.

PURPOSE: To identify patient baseline characteristics that predict recognition acuity at 4.5 years of age in the Infant Aphakia Treatment Study, a study of patients with monocular infantile cataracts. METHODS: We analyzed baseline characteristics of the 114 infants enrolled in the Infant Aphakia Treatment Study to determine which were most predictive of visual outcome at 4.5 years of age. All infants underwent cataract surgery between 1 and 7 months of age. Monocular acuity was assessed at 4.5 years of age by a traveling examiner using the Amblyopia Treatment Study HOTV protocol. RESULTS: Age at cataract surgery was weakly associated with visual acuity (Spearman rank correlation coefficient = 0.19, P = 0.041) with median visual acuity better among the younger patients (28-48 days: 0.50 logMAR, 49-210 days: 1.10 logMAR, P = 0.046). Patients from families with private insurance had significantly better median visual acuity (0.60 vs. 1.40 logMAR, P = 0.0004). No other baseline characteristic revealed a significant bivariate relationship with visual acuity. A multiple linear regression relating visual acuity to all baseline characteristics demonstrated that only the availability of private insurance was statistically significant, accounting for 12% of the variance. CONCLUSIONS: This analysis concurs with previous studies that early surgery is important for good visual outcomes in patients with unilateral infantile cataracts. The fact that only one baseline variable (private insurance) contributed to the multivariate analysis, accounting for 12% of the variance, suggests that predicting visual outcome for these patients is complicated at best, and cannot be estimated from baseline characteristics alone. (ClinicalTrials.gov number, NCT00212134.).

Relationship between monocularly deprivation and amblyopia rats and visual system development.

OBJECTIVE: To explore the changes of lateral geniculate body and visual cortex in monocular strabismus and form deprived amblyopic rat, and visual development plastic stage and visual plasticity in adult rats. METHODS: A total of 60 SD rats ages 13 d were randomly divided into A, B, C three groups with 20 in each group, group A was set as the normal control group without any processing, group B was strabismus amblyopic group, using the unilateral extraocular rectus resection to establish the strabismus amblyopia model, group C was monocular form deprivation amblyopia group using unilateral eyelid edge resection + lid suture. At visual developmental early phase (P25), meta phase (P35), late phase (P45) and adult phase (P120), the lateral geniculate body and visual cortex area 17 of five rats in each group were exacted for C-fos Immunocytochemistry. Neuron morphological changes in lateral geniculate body and visual cortex was observed, the positive neurons differences of C-fos expression induced by light stimulation was measured in each group, and the condition of radiation development of P120 amblyopic adult rats was observed. RESULTS: In groups B and C, C-fos positive cells were significantly lower than the control group at P25 (P<0.05), there was no statistical difference of C-fos protein positive cells between group B and group A (P>0.05), C-fos protein positive cells level of group B was significantly lower than that of group A (P<0.05). The binoculus C-fos protein positive cells level of groups B and C were significantly higher than that of control group at P35, P45 and P120 with statistically significant differences (P<0.05). CONCLUSIONS: The increasing of C-fos expression in geniculate body and visual cortex neurons of adult amblyopia suggests the visual cortex neurons exist a certain degree of visual plasticity.

Expression of collapsin response mediator protein 2 in visual cortex of form deprivation amblyopic rats / 中华实验眼科杂志

Objective To study the expression of collapsin response mediator protein 2 (CRMP-2) in the visual cortex of monocular form deprivation amblyopia rats.Methods Sixty-four 14-day-old rats were randomly divided into monocular deprivation amblyopia group and normal control group by random number table method.Right eyelid margin suture was performed at 14 days after birth in the monocular deprivation amblyopia group.Eight rats in the monocular deprivation amblyopia group and the normal control group were observed at 14,21,45 and 120 days after birth,respectively.Flash visual evoked potential (F-VEP) was used to dectect the latency and amplitude of P1 wave.The expression of CRMP-2 in visual cortex was observed by immunohistochemical method.The use and care of the animals complied with Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.This study protocol was approved by Ethic Committee of the University of South China (No.20140228).Results F-VEP results showed that the amplitudes of P1 were decreased and latent periods of P1 were prolonged in the monocular deprivation amblyopia group compared with the normal control group (t=16.760,P =0.000;t =-22.919,P =0.000).CRMP-2 expression levels in the visual cortex of monocular deprivation amblyopia groups and normal control groups were compared at different time points after birth,and the differences were statistically significant (Fgroup =8.855,P =0.010;Ftime =63.091,P =0.000).Compared with normal control groups,the expressions of CRMP-2 at the postnatal 21,45 and 120 days were obviously decreased in the monocular deprivation amblyopia groups,the differences were statistically significant (all at P＜0.05).Conclusions CRMP-2 may be involved in the occurrence and development of amblyopia.

Sensory experience during locomotion promotes recovery of function in adult visual cortex.

Recovery from sensory deprivation is slow and incomplete in adult visual cortex. In this study, we show that visual stimulation during locomotion, which increases the gain of visual responses in primary visual cortex, dramatically enhances recovery in the mouse. Excitatory neurons regained normal levels of response, while narrow-spiking (inhibitory) neurons remained less active. Visual stimulation or locomotion alone did not enhance recovery. Responses to the particular visual stimuli viewed by the animal during locomotion recovered, while those to another normally effective stimulus did not, suggesting that locomotion promotes the recovery only of the neural circuits that are activated concurrent with the locomotion. These findings may provide an avenue for improving recovery from amblyopia in humans.DOI: http://dx.doi.org/10.7554/eLife.02798.001.

Relationship between monocularly deprivation and amblyopia rats and visual system development

OBJECTIVE@#To explore the changes of lateral geniculate body and visual cortex in monocular strabismus and form deprived amblyopic rat, and visual development plastic stage and visual plasticity in adult rats.@*METHODS@#A total of 60 SD rats ages 13 d were randomly divided into A, B, C three groups with 20 in each group, group A was set as the normal control group without any processing, group B was strabismus amblyopic group, using the unilateral extraocular rectus resection to establish the strabismus amblyopia model, group C was monocular form deprivation amblyopia group using unilateral eyelid edge resection + lid suture. At visual developmental early phase (P25), meta phase (P35), late phase (P45) and adult phase (P120), the lateral geniculate body and visual cortex area 17 of five rats in each group were exacted for C-fos Immunocytochemistry. Neuron morphological changes in lateral geniculate body and visual cortex was observed, the positive neurons differences of C-fos expression induced by light stimulation was measured in each group, and the condition of radiation development of P120 amblyopic adult rats was observed.@*RESULTS@#In groups B and C, C-fos positive cells were significantly lower than the control group at P25 (P0.05), C-fos protein positive cells level of group B was significantly lower than that of group A (P<0.05). The binoculus C-fos protein positive cells level of groups B and C were significantly higher than that of control group at P35, P45 and P120 with statistically significant differences (P<0.05).@*CONCLUSIONS@#The increasing of C-fos expression in geniculate body and visual cortex neurons of adult amblyopia suggests the visual cortex neurons exist a certain degree of visual plasticity.

Expression of ciliary neurotrophic factor in visual cortex of form deprivation amblyopia cat and its effect / 中华实验眼科杂志

Background Researches demonstrated that ciliary neurotrophic factor (CNTF) can enhance survival and promote differentiation of neutron.Meanwhile,CNTF also is thought to play an important role in the development of visual pathway.But,less studies are reported in the relationship of CNTF and form deprivation amblyopia.Objective This study was to investigate the expressions of CNTF in visual cortex area 17 in form deprivation amblyopia model.Methods Twelve 4-week-old cats were randomized into normal group and form deprivation amblyopia group.Monocular form deprivation amblyopic models were established in 6 cats by eyelids suture method.Pattern visual evoked potential(P-VEP) was recorded to evaluate the amblyopic models 16 weeks later following the eyelids suturing.Then,bilateral visual cortex tissue was incised at a vertical in sagittal axis fashion to prepare the section.Nissl staining was used to detect the morphologies of neurons.Expression of CNTF in Ⅰ-Ⅵ layers of visual cortex area 17 was located and quantified by immunochemistry.The positive cell number and gray scale for CNTF were calculated and compared between two groups.The use of the animals complied with Regulations for the Administration of Affairs Coucerning Experimental Animals by State Science and Technology Commission.Results Compared with the normal group,P-VEP amplitude was significantly reduced (6.11 ±1.56 μV vs.11.42±t.92 μV) and latency was significantly prolonged(75.77±9.83 ms vs.58.56±7.17 ms) in the form deprivation amblyopia group (t=5.272,3.464,P＜0.05).Nissl staining showed that the number of neurons in the form deprivation amblyopia group was less than that in the normal group.In the form deprivation amblyopia group,neurons became shrinkage and turned round,cytoplasmic processes get shortened,and the nucleus became small.The number of Nissl bodies was decreased.lmmunochemistry showed the positive neutrons for CNTF in Ⅰ-Ⅵ layers of visual cortex area 17 in hoth normal cats and model cats with the more positive cells in Ⅱ-Ⅳ layers.Compared with the normal group,the positive cell number for CNTF was significantly reduced in Ⅱ-Ⅳ layers of visual cortex area 17 in the form deprivation amblyopia group (Ⅱ layer:95.93±8.24 vs.116.25±6.52;I layer:102.65±7.45 vs.125.23±8.21;Ⅳ layer:l10.65±6.85 vs.139.54±4.26) (t=4.737,4.989,8.773,P＜0.05).In addition,the gray scale of CNTF positive cells was significantly lower in Ⅱ-Ⅳ layers of visual cortex area 17 in the form deprivation amblyopia group than that the normal group (Ⅱ layer:106.98 ± 8.86 vs.138.65 ± 6.38 ; Ⅲ layer:109.56 ± 8.69 vs.149.59 ±8.55;Ⅳ layer:l16.65 ±9.52 vs.155.76±9.87) (t=7.105,8.043,6.986,P＜0.05).Both CNTF positive cell number and gray scale in Ⅰ,Ⅴ,Ⅵ layers of visual cortex area 17 had no significant differences between two groups (P＞0.05).Conclusions Form deprivation in critical period of a new born animal may lead to distributing abnormality of CNTF in visual cortex,which maybe play a role in the development of form deprived amblyopia.