Functional vision assessment in children with Cerebral Visual Impairment

This project is conducted under the supervision of Dr Nienke Boonstra, Prof.Dr.N Jansonius, Prof. Dr. A Cillessen and Dr Bianca Huurneman at the Royal Dutch Visio, Nijmegen in collaboration with Radboud University and aims to streamline the diagnostic criteria for children with CVI in order to improve the available Dutch guidelines.

Personal Background and Interest:

A master’s graduate in optometry and vision science at the Elite school of optometry, India with clinical experience in multidisciplinary diagnosis and rehabilitation of children with CVI and special needs population.

Aims of the project:

The objective of my project is to objectively assess functional vision including combined visual- and motor reaction time in children with CVI. The project has been focussed on studying the structural and functional correlates of CVI and its subtypes using existing visual function methods and techniques. The resulting objectives are to 1) classify childhood CVI based on functional and structural measures; 2) test speed acuity during visual and auditory tasks, and perform developmental eye movement test and eye movement analysis in different groups of CVI; and 3) understand the structural and functional correlates of childhood CVI.

Current activities:

To date, I have performed a pilot study using a pre-existing database of children (developmental age 3-18 yrs) with CVI in order to classify CVI based on different visual functional measurements. Classifying CVI into subtypes will aid in: i) better understanding of the disease, ii) simplifying the diagnosis by reduction of diagnostic measures in multiple impaired children, and iii) framing educational and interventional strategies. Previous classifications were based only on basic visual functions and failed to incorporate other key features required in CVI diagnosis such as aspects of the optic disc, visual fields, and fixation and eye movements. This current study included these key features along with core visual functions which made up an extensive test battery (with 7 variables: visual acuity, contrast sensitivity, ocular alignment, evaluation of visual perception, visual fields, optic disc changes and eye movement analysis). This test battery was compared to a limited test battery consisting of basic visual function measures (with 4 variables: visual acuity, contrast sensitivity, ocular alignment and evaluation of visual perception). This comparison of classification outcomes should provide information about the value of an extensive test battery over a limited test battery.

In addition, I have been working on standardizing both the technical and practical aspects of taking OCT measurements in children at Visio.

Lastly, I have been collecting CVI patient data since June 2022. Data collection included various visual function measures including visual fields, crowding, eye tracking and speed acuity. 

Future directions:

I plan to apply a similar analysis as the pilot study described above, to the newly acquired CVI patient data to establish a reliable classification for childhood CVI in a larger sample size.