APPENDIX A: Summary of main themes, sub-themes and study outcomes relating to communication and language characteristics of young children with VI.

Main themes	Article	Sub-themes	Study outcomes
Early intervention	Dammeyer, 2012	Language abilities Congenital VI	No formal test for the language evaluation of children with deafblindness. Language delay was estimated using informal procedures and a rating scale 15 (n26) children with Usher presented with little or no language delay 3 (n17) children with CHARGE presented with little or no language delay Late age of walking may be an early predictor for: - cognitive and language delays in CHARGE syndrome - cognitive delay in Usher syndrome The combination of VI, hearing loss and delayed motor skills provided additional barriers for language, cognitive and social development. There was a correlation between the degree of deafblindness and the language delay in Usher. There was a correlation between the degree of intellectual disability and language delay in Usher and CHARGE.
		Lack of assessment tool Cognitive impairment Multiple disabilities
	Peltzer-Karpf, 2012	Language abilities Pragmatic skills Congenital VI Neuroimaging	In children with congenital VI, the visual areas of the brain are used for non-visual tasks, such as auditory language processing. Language acquisition in children with sensory impairment follows the same overall pattern to sighted or hearing children in terms of macrostructural changes, but various subsystems, within vision, hearing, language and attention, are selectively affected. Therefore there are time lags that are most evident in the early stages of development. Development of neural systems for syntax takes longer than systems for semantics. Due to the absence of lip reading, there is extended sound sorting and delays in phonological learning. Congenital VI results in the lack of referential gaze, which causes slower concept formation. This affects morphological and syntactic development. Initially, the single-word stage is delayed, but this is followed by intense lexical acceleration rate.
			Language delay decreases with age and maturity, resulting in developmental profiles process-oriented and not age-matched. Interdisciplinary, process-oriented research helps to apply multifaceted training programs as early and efficiently as possible to optimise children’s development
	Funnell & Wilding, 2011	Language abilities Speech production	Language delay identified from the age of two years. Progressive receptive and expressive language delay over the years. Phonology and articulation were normal as the systems are not dependent on vision. Severely impaired visual object naming contrasted with normal understanding of the spoken names of objects.
	Parr et al., 2010	Pragmatic skills Language abilities Congenital VI Lack of assessment tool ASD Multiple disabilities	Standard measures of social communication development and ASD are not available for young children with VI.
			There was at least one SCRR difficulty in 48 (n83) of the participants. 37% of the sample had difficulties in all three domains. Children with one or more SCRR and ASD have a developmental quotient within the learning difficulty range when compared to norms of children with VI. Basic form vision is not sufficient to support early social and communication development in children with ONH and SOD.
	Peltokorpi & Huttunen, 2008	Communication abilities Language abilities Pragmatic skills Congenital VI Stereotyped behaviour Multiple disabilities Parent-child interaction Tool modification required	Communication was impacted from the preverbal stage due to deafblindness, hospitalisation and facial paralysis.
			Children with CHARGE demonstrate more stereotypical behaviour than other children with deafblindness.
			All the children (n3): - used mainly gestures - made initiations slightly under half of the total number of communication expressions, indicating active involvement - used eye contact but limited even though sight was used to explore toys - showed limited requesting - protesting was the most common communication function. Intentional communicative acts were present in all three participants, but the frequency was low compared to the total number of communicative acts. Children with multiple disabilities demonstrate only some intentional communication in early stages of language development.
			Careful examinations of the communicative behaviour between a child and parent can serve as a basis for early intervention.
			Atypical features of visual behaviour make interpreting communication challenging. Audiological management is important for the development of communication and language in children with CHARGE.
	Rattray & Zeedyk, 2005	Communication abilities Communication means Pragmatic skills Parent-child interaction	All mothers used activ etouch as a mode for communication, but mothers of children with VI used increased active touch before gradually decreasing it. All mothers and infants showed more active and passive touch during shared attention, indicating that touch is a communication means. Active touch is prominent in children with VI as a tactile form of communication due to the lack of visual communication during shared attention. All mothers and children used increased vocalisations during joint attention as a means of communication.
			VI, of mother or child, may affect the overall rate of vocalisation, but is still used as a means of communication.
			All mothers and children used facial orientation during shared attention, but less than touch and vocalisations, indicating that facial orientation is not as important as a communication means. VI itself does not automatically decrease the quality of communication interactions between mothers and infants, but does necessitate the reliance on alternative, non-visual communication means. The VI status of the mother and/or child impacts the communication interaction. Mothers have an important role in children’s communication acquisition.
	Ashkenazy et al., 2005	Language abilities Emotional status Parent-child interaction Congenital VI	Receptive language attainments were significantly affected by the child’s emotional and behavioural status.
			The interaction between the child’s age and the mother’s level of education impacts on receptive language: older children of mothers with less education show compromised receptive language abilities. Expressive language attainments were associated with the child’s emotional and behavioural status and not significantly with the mother’s level of education. There was a strong association between development and a child with VI’s emotional and behavioural status.
			Early identification and treatment of emotional and behavioural problems lead to better emotional status and thus improved development