Effects of scleral buckling and encircling procedures on human optic nerve head and retinochoroidal circulation

AIMS: To study the effects of segmental scleral buckling and encircling procedures on tissue circulation in the human optic nerve head (ONH) and choroid and retina. METHODS: Using the laser speckle method, the normalised blur (NB) value, a quantitative index of tissue blood velocity, was measured every 0.125 seconds and averaged over three pulses in the optic nerve head (NB(ONH)) and choroid and retina (NB(ch-ret)) in 10 patients with unilateral rhegmatogenous retinal detachment (mean age 52 (SD 17)). NB(ONH), NB(ch-ret), and intraocular pressure (IOP) in both eyes, and blood pressure (BP) were measured before, and 1, 4, and 12 weeks after the scleral buckling and encircling procedure. RESULTS: NB(ch-ret) on the buckled side was significantly reduced after surgery and smaller than that in the unoperated contralateral eye throughout the study period (ANOVA, p<0.0001). NB(ch-ret) on the unbuckled side, in the foveal area, NB(ONH), IOP, and BP showed no significant change. CONCLUSIONS: It was indicated that the segmental scleral buckling procedure with encircling elements decreased tissue blood velocity in the choroid and retina on the buckled side but caused no significant change on tissue circulation in other areas of the fundus or ONH.