Assessment of Lens Center Using Optical Coherence Tomography, Magnetic Resonance Imaging, and Photographs of the Anterior Segment of the Eye

PURPOSE. To determine the nearest marker for evaluating the center of the crystalline lens using optical coherence tomography (OCT), magnetic resonance imaging (MRI), and photographs. METHODS. Optical coherence tomography scans of human eyes were obtained in vivo during femtosecond laser-assisted cataract surgery. From axial and sagittal images, the distance of the angle center (AC) and pupil center (PC) from the scanned capsule center (SCC) was calculated. From pre- and postoperative photographs, the distance of the PC and limbal center (LC) from the intraocular lens (IOL) center was calculated, and distance between each center on the lens equatorial plane was compared. After combination of pre- and postoperative images, we arranged the centers in order of distance from the IOL center. High-resolution MRI was performed in pig eyes ex vivo to confirm the exact location of the lens center relative to other centers. RESULTS. In human OCT scans and photographs (n = 76), the IOL center to AC distance was 0.22 6 +/- 0.13 mm, the IOL center to SCC distance was 0.22 +/- 0.12 mm, the IOL center to PC distance was 0.25 +/- 0.17 mm, and the IOL center to LC distance was 0.30 +/- 0.18 mm. The AC and SCC were significantly closer to the IOL center than the PC or LC. In MRI (n = 54 images), the lens center to AC distance was 0.90 +/- 0.58 mm, and the lens center to PC distance was 1.53 +/- 0.87 mm (D distance = 0.63 +/- 0.69 mm, P = 0.000). CONCLUSIONS. Optical coherence tomography, MRI, and photographs of the anterior segment revealed that the AC is the nearest marker to the center of the lens equator.