Aim To correlate light increment sensitivity (LIS) and visual acuity (VA) with birth weight (BW), gestational age (GA) and stage of acute retinopathy of prematurity (ROP) (STG) in premature children at school age.

Methods 180 children (150 former prematures and 30 age-matched term-born children) were enrolled at age 6-13years. Former prematures were categorised by the results of the initial ROP screening based on digital wide-field fundus imaging: absence of ROP (n=100) and spontaneously resolved ROP (n=50). The latter group was further subdivided according to their STG (Stg 1; Stg 2; Stg 3). Both groups were categorised into sectors by BW (<1000g; 1000-1500g; >1500g), and GA (28weeks; >28<32weeks; 32weeks). VA was assessed with Early Treatment of Diabetic Retinopathy Study letters, LIS was measured at 0 degrees, 2.8 degrees and 8 degrees in the visual field (Microperimeter MP1, Nidek Technologies), and spherical equivalent refraction assessed with a Nidek autorefractor (Nidek, Italy).

Results Central and pericentral LIS (0 degrees and 2.8 degrees) and VA were significantly lower in all groups and sectors compared with term-born controls except for BW >1500g for LIS and GA >28 to <32 W for VA. No significant differences were found for LIS at 8 degrees in all groups. No correlation was found between LIS and VA on an individual basis.

Conclusions Low BW, GA and increasing severity of spontaneously resolving ROP were associated with significantly decreased central visual function. In addition to VA, LIS measurement further describes foveal function and is a unique parameter to assess parafoveal function.