A complete ophthalmic examination is not routinely performed on infants with 
Miller-Dieker syndrome (MDS, chromosome 17p13.3 microdeletion). The authors 
present the cases of four cousins with MDS who also carried a 16p13.3 
microduplication (not associated with Rubinstein-Taybi syndrome). Retinopathy of 
prematurity-like proliferative peripheral retinopathy (PPR) was detected in two 
male first cousins, but was not detected in the female half-cousins. PPR in the 
first infant resolved by 4 months, but the second infant's PPR progressed, 
requiring photocoagulation followed by lens-sparing vitrectomy. While ocular 
abnormalities are more prevalent and severe in other lissencephalopathies, the 
PPR in these MDS infants underscores the sight-saving potential of performing an 
ophthalmologic exam with early molecular testing for all lissencephaly infants.