Long-term changes in axial length in adult eyes with pathologic myopia.

OBJECTIVE

To examine the long-term changes of the axial length in adults with high myopia.

DESIGN

Open-label, consecutive, retrospective case series.

METHODS

The medical records of 101 patients (184 eyes) with high myopia (myopia ≥-6 diopters or axial length ≥26.5 mm) were studied. The axial length of the eye was measured by A-scan ultrasonography. The significance of the changes in the axial length during follow-up was determined. The effects of the age, axial length, and the presence of a posterior staphyloma at the initial examination on the axial length elongation were determined.

RESULTS

The mean follow-up period was 8.2 years. The median axial length increased significantly from 28.6 mm at the initial examination to 29.4 mm at the final examination in the 184 eyes. The axial length remained stable (≤1-mm difference) in 69%, whereas the axial length increased by more than 1 mm in 31% of the eyes. For these 31%, the median axial length increased by 1.55 mm. An increase of the axial length per year was significantly greater in older patients than their younger cohorts, and the increase in eyes with a posterior staphyloma was significantly greater than in eyes without a staphyloma. Multiple regression analyses showed that the axial length elongation was positively and significantly correlated with patient age at the initial examination.

CONCLUSIONS

In highly myopic adult patients, the axial length continued to increase. Older individuals with posterior staphyloma were more susceptible to having a larger increase in the axial length. A progression of posterior staphyloma with increasing age is considered a key factor for the continuous increase of axial length in adults with high myopia.