[Biometric variation of the ocular globe in myopia]

The study of correlation between myopia's pathogen and the biometrics variations of the different eye ball segments.

64 patients were included in this study: 54 patients with myopia higher than--5 diopter and 10 patients with cataracta. All patients underwent a complete ocular examination including: visual acuity determination, ocular fundus examination, automatic refractometry, keratometry. Biometry was performed with an ultra-scan system.

From 64 patients, 53 were with axial myopia, 1 with myopia induced by low corneal curvature radius and 10 patients with myopia induced by a high refractive index of the lens caused by cataract. In cases with axial myopia the axial length was high (26.1 mm) with a high vitreous length (20.78 mm). In cases with index myopia, only the lens thickness and the anterior chamber depth undergo biometrics variations. Curvature myopia is the result of the decrease of the corneal curvature radius.

Axial myopia is that by far the most frequently form of myopia. In this case the increases in axial length is proportionally with the degree of myopia. Index myopia is produced by the increase of the refractive index of the lens in cataract. A low corneal curvature radius less frequently than the others produces curvature myopia.