The highly myopic eye--oculometric considerations

After a brief historical oculometry review, the purpose is to bring a longitudinal update on an unselected Danish high myopia series, which was first presented at 1978 SIDUO. The sample was recruited from a Copenhagen school cohort (N=9,423, born 1948) as 14-year-olds with myopia of at least -6 D (n=39) in 1962. Clinical follow-up studies were conducted in 1976, 1986, 1995 and 2002, with A-scan ultrasound oculometry (Kretztechnik 7000, immersion method; and Sonometrics 400, contact method) as a regular part of the schedule. For comparison, IOL Master evaluations were added in 2002. The following results and conclusions were made: (a) up to age 54, most subjects had maintained good or fair vision; (b) as in other myopia series, axial and vitreous length were found to be the most important optical parameters, with corneal curvature radius ranking next; (c) however, as previously described by Francois and Goes, not all long eyes have flat corneas. In our high myopia series, a significant subgroup could thus be discerned who had peaked corneas, which led to mathematically slight reduction of the usual positive correlation between axial length and curvature radius in the ametropia population; and (d) we found positive correlation between myopia increase in adult age and axial elongation, stressing that, in contrast to other outgrown body structures, the adult eye globes may still expand in size. This feature seems to be found not only in the eyes with posterior staphyloma, but also in myopic eyes of regular round shape.