HYPOTHESIS - MYOPIA OF PREMATURITY IS CAUSED BY POSTNATAL BONE-MINERAL DEFICIENCY

Myopia is a frequent finding in preterm children. The close associatio n between myopia and retinopathy of prematurity (ROP) suggested a caus al relationship, but myopia of prematurity without ROP has yet to be e xplained. An alternative explanation is presented: myopia is caused by postnatal ellipsoid deformation of the spheric eyeball, i.e. excessiv e elongation of the optical, as a result of a dolichocephalic deformat ion of the skull with a short frontal axis. This deformation of the sk ull is the direct result of bone mineral deficiency frequently observe d in very low birth weight infants with increasing postnatal age. This hypothesis is supported by the results of a historical comparison of very low birth weight infants without and with supplementation with ca lcium and phosphorus that was given in order to prevent postnatal bone mineral deficiency. In the unsupplemented group 4 of 23 children (61% ) needed spectacles but only 6 out of 55 (11%) children who were suppl emented as babies (questionnaire). Refraction measurements showed myop ia stronger than -1 o.d. in group 1 in 5 of 14 infants, whereas in gro up 2 only 2 out of 22 infants were myopic (P < 0.05).