The diameter of the ciliary sulcus: a morphometric study.

Based on a precise definition of boundaries of the ciliary sulcus, a new anatomical method was used to measure the diameter of the ciliary sulcus in postmortem eyes. In each of 41 globes, 24 different ciliary sulcus diameters were measured and were compared with the axial length, measured by ultrasonography. The mean ciliary sulcus diameter was 11.25 mm (SD = 0.38 mm). By linear regression, the axial length values were significantly correlated with ciliary sulcus diameters. In addition, our data suggest that existence of two groups of eyes differentiated exclusively by the diameter of the ciliary sulcus, independent of the axial length. We propose that the displacement of the pars plicata corporis ciliaris from the peripheral iris to the iris root during the embryonic period may be incomplete in eyes of shorter axial length. The findings of the present study may play a role in cataract surgery in which an intraocular lens is inserted into the ciliary sulcus.