Convergence and accommodation development is 1 pre - programmed in premature infants 2 Anna

28 Purpose This study investigated whether vergence and accommodation development in pre29 term infants is pre-programmed or is driven by experience. 30 Methods 32 healthy infants, born at mean 34 weeks gestation (range 31.2-36 weeks) were 31 compared with 45 healthy full-term infants (mean 40.0 weeks) over a 6 month period, starting at 32 4-6 weeks post-natally. Simultaneous accommodation and convergence to a detailed target 33 were measured using a Plusoptix PowerRefII infra-red photorefractor as a target moved 34 between 0.33m and 2m. Stimulus/response gains and responses at 0.33m and 2m were 35 compared by both corrected (gestational) age and chronological (post-natal) age. 36 Results When compared by their corrected age, pre-term and full-term infants showed few 37 significant differences in vergence and accommodation responses after 6-7 weeks of age. 38 However, when compared by chronological age, pre-term infants’ responses were more 39 variable, with significantly reduced vergence gains, reduced vergence response at 0.33m, 40 reduced accommodation gain, and increased accommodation at 2m, compared to full-term 41 infants between 8-13 weeks after birth. 42 Conclusions When matched by corrected age, vergence and accommodation in pre-term 43 infants show few differences from full-term infants’ responses. Maturation appears pre44 programmed and is not advanced by visual experience. Longer periods of immature visual 45 responses might leave pre-term infants more at risk of development of oculomotor deficits such 46