Cataract in children

Modeling ocular lens disease in Xenopus

BACKGROUND

Ocular lens clouding is termed as cataract, which depending on the onset, is classified as congenital or age-related. Developing new cataract treatments requires new models. Thus far, Xenopus embryos have not been evaluated as a system for studying cataract.

RESULTS

We characterized the developmental process of lens formation in Xenopus laevis tailbuds and tadpoles, and we disrupted the orthologues of three mammalian cataract-linked genes in F0 by CRISPR/Cas9. We assessed the consequences of gene inactivation by combining external examination with histochemical analyses and functional vision assays. Inactivating the key metazoan eye development transcription factor gene pax6 produces a strong eye phenotype including an absence of eye tissue. Inactivating the genes for gap-junction protein and a nuclease, gja8 and dnase2b, produces lens defects that share several features of human cataracts, including impaired vision acuity, nuclei retention in lens fiber cells, and actin fibers disorganization. We tested the potential improvement of the visual acuity of gja8 crispant tadpoles upon treatment with the molecular chaperone 4-phenylbutyrate.

CONCLUSION

Xenopus is a valuable model organism to understand the molecular pathology of congenital eye defects, including cataracts, and to screen molecules with a potential to prevent or reverse cataracts.

Quality of life and functional vision in children treated for cataract-a cross-sectional study

PurposeChildren with cataract and their families face intensive medical and surgical management, with numerous hospital attendances, topical medications, and surgical procedures, as well as uncertainty about the child's future visual ability, education, and independence. Little is known about the impact on functional visual ability, vision-, and health-related quality of life (VR-, HR-QoL).Patients and methodsSeventy two children aged 2-16 years (mean 8.45, SD 4.1) treated for developmental or secondary cataract and their parents/carers completed three validated instruments measuring functional visual ability, VR-, and HR-QoL: the Cardiff Visual Ability Questionnaire for Children (CVAQC), Impact of Vision Impairment for Children (IVI-C), and PedsQL V 4.0.ResultsAll scores are markedly reduced: median (interquartile range (IQR)) CVAQC score -1.42 (-2.28 to -0.03), mean (SD) IVI-C score 65.67 (16.91), median (IQR) PedsQL family impact score 75 (56.94-88.19), parent report 71.74 (51.98-88.5), self-report 76.09 (61.96-89.13). Psychosocial PedsQL subscores are lower than physical subscores. Parent-completed tools (PedsQL family and parent report) state greater impact on HR-QoL than tools completed by children/young people, particularly in teenagers. Older children/young people have higher functional visual ability scores than younger children.ConclusionsCataract has a marked a long-term impact on functional visual ability and quality of life of children and young people, with HR-QoL affected to degrees reported in children with severe congenital cardiac defects or liver transplants.

Symptom based diagnosis of infant under one year in outpatient clinic

PURPOSE

We investigated chief complaints and ocular disorders in infants under one year of age and analyzed the association between complaints and disorders.

METHODS

The medical records of 815 infants were reviewed. Chief complaints were grouped into the following 11 categories: eyelid drooping, epiphora (tearing), ocular discharge, lid swelling, eyelashes touching the eyeball, abnormalities of the anterior segment, abnormal eyeball movement (e.g., squint or nystagmus), red eye, trauma, poor eye contact, and miscellaneous. We performed ophthalmologic examinations at the doctors' discretion and analyzed the relationship between chief complaint and final diagnosis.

RESULTS

Mean age of visiting the outpatient clinic was 6.09 ± 3.07 months. The most common complaint was ocular discharge, followed by abnormal eyeball movement, epiphora, and eye redness. Among infants with ocular discharge, most were attributed to congenital nasolacrimal duct obstruction (155 infants) and conjunctivitis (75 infants). A total of 160 guardians complained of abnormal eyeball movement and 86 of 160 infants (51.9%) suffered from pseudoesotropia. Additionally, exodeviation and esodeviation was found in 17.9% and 16.4% of infants, respectively. Eight guardian complained of poor eye contact in their infants and these infants were diagnosed with retinal disorders (3), congenital optic nerve disorders (2), cataract (1), glaucoma (1), and high hyperopia (1).

CONCLUSIONS

The most common ocular symptoms in infants under one year of age included ocular discharge, epiphora, and eye redness. However, infants with poor eye contact or suspected abnormal eye movement should undergo a full ophthalmologic examination.

[Examination methods in the diagnosis of uni- and bilateral cataracts in childhood]

Today, the management of congenital and developmental pediatric uni- and bilateral cataract is still a problem, particularly because untreated lens opacity has a high amblyogenic potential. Such irreversible deprivation amblyopia in pediatric cataracts requires an early diagnosis. Due to the increased inflammatory reaction postoperatively, a minimally traumatic operation, intensive occlusion therapy and optimal correction with glasses or contact lenses are also necessary. Uni- and bilateral cataracts and their preoperative diagnostics have to be considered separately.

2005 Gregg Lecture: Congenital cataract--from rubella to genetics

On the 65th anniversary of Gregg's observation "Congenital cataract following German measles in the mother", rubella has retired as the leading cause of congenital cataract, from 87% of Gregg's cohort to less than 3% over the last 25 years and almost zero now in Australia and other developed countries. However, people must keep vigilance in maintaining immunization rates and encourage immunization in developing countries. At least one-fifth of congenital cataract is familial. Understanding the genetics of familial cataract will lead to better treatment of congenital as well as age-related cataract.