Axial length measurements and fundus changes of the myopic eye

In this study of the relationship of myopic fundus changes and axial length in 1437 eyes the following results were obtained: Crescent formation was demonstrated as directly related to increased axial length in incidence (p < .01) as well as type and size. Chorioretinal atrophy was demonstrated to be related to increased axial length (p < .01) but age also plays an important role in the production of this defect (p < .01). Fuchs' spots and lacquer cracks, although occurring in eyes of greater axial length, cannot be directly correlated with increasing axial length. This is possibly the result of changes in the morphology of these lesions with age. Posterior staphyloma is directly related to increased axial length (p < .01). Crescent formation is present in all eyes exhibiting other myopic fundus lesions. Chorioretinal atrophy occurs very frequently in eyes with Fuchs' spots. Chorioretinal atrophy usually of an extensive degree occurs in eyes of patients above the age of 40 years who have posterior staphyloma. Although these results do not conclusively rule out abiotrophy in the pathogenesis of myopic fundus changes the significant correlation of crescent formation, chorioretinal atrophy and posterior staphyloma with increased axial length is strongly suggestive of some element of biomechanical effect. The occurrence of these myopic changes in patients with the connective tissue diseases of Marfan's syndrome and Ehlers-Danlos syndrome also tend to indicate the involvement of biomechanical factors. This conclusion is further supported by two previous uniovular twin studies and tentatively, by the fundus changes in the myopia of prematurity.