Results of late surgical intervention in children with early-onset bilateral cataracts

Abstract

Background Cataracts are a major cause of childhood blindness globally. Although surgically treatable, it is unclear whether children would benefit from such interventions beyond the first few years of life, which are believed to constitute `critical' periods for visual development. Aims To study visual acuity outcomes after late treatment of early-onset cataracts and also to determine whether there are longitudinal changes in postoperative acuity. Methods We identified 53 children with dense cataracts with an onset within the first half-year after birth through a survey of over 20 000 rural children in India. All had accompanying nystagmus and were older than 8 years of age at the time of treatment. They underwent bilateral cataract surgery and intraocular lens implantation. We then assessed their best-corrected visual acuity 6 weeks and 6 months after surgery. Results 48 children from the pool of 53 showed improvement in their visual acuity after surgery. Our longitudinal assessments demonstrated further improvements in visual acuity for the majority of these children proceeding from the 6-week to 6-month assessment. Interestingly, older children in our subject pool did not differ significantly from the younger ones in the extent of improvement they exhibit. Conclusions and relevance Our results demonstrate that not only can significant vision be acquired until late in childhood, but that neural processes underlying even basic aspects of vision like resolution acuity remain malleable until at least adolescence. These data argue for the provision of cataract treatment to all children, irrespective of their age.

Emergence of categorical face perception after extended early-onset blindness

“…This point is especially pertinent given the intersubject variability we see in our results. The variability, which is a common feature of many aspects of the vision of newly sighted children (18,49), does not yet have a satisfactory explanation such as age at treatment. Second, we have considered only one of the many face perception tasks humans perform.…”

“…This harkens to the classical notions of a critical period in visual development (14,15). Several findings suggest that low-level aspects of visual function, such as high-resolution vision and binocular depth perception, are subject to a critical period, and visual deprivation during this period renders impossible their acquisition later in life (14,(16)(17)(18)(19). Do critical periods apply similarly to higher-level visual tasks such as face perception?…”

Assessing the impact of a program for late surgical intervention in early-blind children

“…However, in the future we will conduct the survey before and after treatment to validate the results presented here. Secondly, even though the visual abilities of most patients improve markedly, they are still considered to be visually-impaired because of their below-par acuity and many would still be considered blind according to WHO criteria [14]. This may be why patients and their families perceived the least improvement in social situations and future prospects.…”

“…Its operations are currently focused on India that has an estimated 200,000 to 700,000 blind children, nearly 40% of whom have preventable or treatable conditions [10-12]. Results from Project Prakash show that after treatment for congenital cataracts, patients are able to acquire proficiency on an array of visual dimensions, ranging from basic functions such as acuity and contrast sensitivity [13, 14] to more complex abilities such as face localization and classification, spatial imagery, and mapping between visual and haptic senses [15-17]. Although the children do not reach normal levels for basic visual functions, such as acuity and contrast sensitivity, these findings suggest that the visual system and its underlying neural mechanisms do retain enough plasticity to allow for significant improvements, even late in childhood.…”

Contrast‐balanced binocular treatment in children with deprivation amblyopia

“…Even less is known about treatment for bilateral deprivation amblyopia. Rehabilitation studies are limited to a scattering of rather extreme case studies and an exploration of video game play (Medal of Honor) as a treatment for adults who experienced very short and early bilateral deprivation . If bilateral deprivation results in sustained unequal acuity between the eyes, patching or penalisation of the stronger eye is often prescribed, but evidence to support patching for bilateral amblyopia is scant …”