Axial length: a risk factor for cataractogenesis.

INTRODUCTION To evaluate whether eyes with longer axial lengths are associated more often with clinically significant cataracts than eyes with shorter axial lengths. MATERIAL AND METHODS Charts of consecutive patients who underwent cataract surgery by 4 resident surgeons at Los Angeles County Hospital from July 2001 through May 2002 were retrospectively reviewed. Those patients whose axial lengths were significantly different between the 2 eyes (>or=0.30 mm) and who had no pathology (other than cataracts) affecting visual acuity were included in the study. The 2 eyes in each patient were compared for preoperative best-corrected visual acuity and severity of cataracts. RESULTS Thirty-four of 353 patients had interocular axial length differences of at least 0.3 mm and were included in this study. Thirty-one patients had worse, 1 had equal, and 2 had better preoperative vision in the eye with longer versus the shorter axial length. Fourteen patients had more severe, 11 had the same, and 1 had less severe posterior subcapsular cataract (PSC) in the eye with longer axial length. In 8 patients, PSC severity could not be assessed due to obscuring nuclear sclerosis. Twenty-four patients had more severe, 7 patients had equal, and 3 patients had less severe nuclear sclerosis in the longer eye. Overall, longer axial lengths correlated with worse visual acuity, posterior subcapsular cataracts, and nuclear sclerosis. Diabetic status did not affect the correlation. The correlations were stronger with greater axial length asymmetry. CONCLUSIONS Eyes with longer axial lengths have a higher prevalence of cataracts.