Outer orbital distance, inner canthal distance and interpupillary distance, proptosis in children with homozygous sickle cell disease.

Background: On basis of clinical observation paediatricians in Kinshasa had the impression that children with homozygous sickle cell disease have a special face characterised by hypertelorism.
Objective: The purpose of the study is to determine outer orbital, inner canthal and interpupillary distances as well as proptosis in children with sickle cell disease.
Methods: These measurements were performed on 66 Congolese children with homozygous sickle cell disease, aged from 2 to 18 years. The measurements were performed with the Hertel exophthalmometer for the proptosis and the outer orbital distance, with the pupillometer model PD-2 meter for the interpupillary distance and with a ruler for the inner canthal distance. The results were compared with those of 95 healthy children of similar age.
Results: All measurements were age related. In every age group the values for inner canthal distance were identical to those of healthy children, but the interpupillary, the outer orbital distances and the proptosis were significantly smaller.
Conclusions: A slow growth of orbital tissue in children with homozygous sickle cell was suggested to explain the difference with healthy children. Other biometric studies comparing the orbital measurements with the rest of the body are needed to confirm or refute this hypothesis.