Ciliary body position variability in glaucoma patients assessed by scleral transillumination.

AIM: To quantify ciliary body position variability in glaucoma patients in order to determine if scleral transillumination should be used routinely to guide contact probe placement during cyclodestructive procedures.
METHOD: This was a prospective experimental study with human subjects. One hundred consecutive glaucoma patients attending a glaucoma clinic were recruited between June and November 2006. A fibre optic light source was used to identify ciliary body position by transscleral transillumination. The distance between the ciliary body and corneoscleral limbus was measured in the superior, temporal, inferior, and nasal quadrants of both eyes using surgical callipers.
RESULTS: The anterior boundary of the ciliary body was located 1.5-5 mm posterior to the corneoscleral limbus. The ciliary body was located significantly more posteriorly in the superior and inferior quadrants compared to the nasal and temporal quadrants. (P<0.001). Ciliary body position was significantly correlated with the mean sphere of the refractive error in phakic patients (r(2)=0.052; P=0.047). The ciliary body tended to be located most posteriorly in myopic eyes.
CONCLUSIONS: The distance between the corneoscleral limbus and the ciliary body as identified by transillumination varies significantly in different quadrants of the eye. Considerable variability was also observed between different patients with glaucoma. Ciliary body transillumination on patients undergoing cyclodestructive procedures may have implications for optimal probe placement and therapeutic outcome.