Purpose:
To determine if eyes with keratoconus have greater axial length, anterior chamber depth, and posterior segment length than emmetropic eyes.
Methods:
We prospectively compared biometric measurements in thirty-six eyes (18 subjects) with keratoconus to 14 emmetropic eyes (7 subjects). Each subject underwent refraction, biomicroscopy, A-scan immersion ultrasonic biometry, and keratometry. The biometric measurements were compared using the independent samples t-test.
Results:
Axial length, anterior chamber depth, and posterior segment length were significantly greater in eyes with keratoconus compared to emmetropic eyes (Table).
Conclusions:
Keratoconus was associated with longer axial length, deeper anterior chamber depth, and longer posterior segment length than emmetropic eyes. Deeper anterior chambers would be expected due to the conical protrusion and steeper curvature of the cornea in keratoconus. However, the greater posterior segment length accounted for most of the increase in total length. Therefore, keratoconus was related to axial myopia, and ocular changes in keratoconus are likely not limited to the cornea.
Keywords: keratoconus • cornea: clinical science