[Implantation of IOLs with different diameters]

The intraocular lenses (IOLs) commonly used today are 13.5 to 14 mm in diameter, and this diameter is considered by some to be unnecessarily large. The size of the crystalline lens and the diagonal width between the ciliary sulcus were measured in rabbit eyes and human eyes. Then, IOLs with a smaller diameter (12.5 mm) were evaluated after implantation into rabbit eyes. The mean diameter of the human crystalline lens was 9.6 mm and its thickness was 4.1 mm. The mean width of the ciliary sulcus was 11.1 mm. The crystalline lenses of rabbits were larger than those of humans. Decentration and posterior capsular opacification score were 0.33 mm and 0.63 in 12.5 mm IOL, and 0.47 mm and 0.61 in 14.0 mm IOL. Indicating that the result of implanting the 12.5 mm IOL was not inferior to that of implanting the conventional 14 mm IOL. The average width of the ciliary sulcus is 11.1 mm, indicating that a 12.5 mm IOL is of a sufficient size to be firmly fixed in this sulcus. In addition, a 12.5 mm IOL is considered to be safer, because larger lenses may lead to erosion or vessel compression that could induce ischemia or neovascularization.