Biometric measurement of the mouse eye using optical coherence tomography with focal plane advancement

Purpose: To demonstrate that high-resolution biometry is possible in mouse eyes in vivo, using real-time OCT with focal plane advancement by a stepper motor.Methods: OCT images of eyes were taken from nine 29-day-old C57BL/6 mice(18 eyes) on two consecutive days. A custom-built real-time OCT instrument with a stepper motor was used to advance the focal plane from the corneal apex to the retina along the ocular axis. The ocular dimensions were determined by advancement of the stepper motor as it displayed on the OCT scan images.Results: OCT images of the entire eye, including the cornea, anterior chamber, lens, vitreous chamber, and retina, were successfully obtained from both eyes of all mice. The measured average corneal thickness from 18 eyes at the age of 29 days was 90.8 ± 4.6 μm, anterior chamber depth 707.4 ± 21.4 μm, lens thickness 1558.7 ± 18.0 μm, vitreous chamber depth 707.4 ± 21.4 μm and retinal thickness was 186.9 ± 15.1 μm. Total axial length (from the corneal apex to the nerve fiber layer of the retina) was 3003.3 ± 44.1 μm. None of them were significantly different if measured on two consecutive days, and no significant differences were found between measurements in the left and right eyes.Conclusion: By focal plane advancement of a real-time OCT instrument through the mouse eye, highly repeatable measurements of the ocular dimensions were obtained. This novel method may be used to study small animal models of normal and abnormal eye development.