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

Abstract

Aims-To study the eVects 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. (Br J Ophthalmol 2000;84:31-36) Scleral buckling procedures are the treatment of choice for the majority of uncomplicated rhegmatogenous retinal detachments. Postoperative complications related to alterations in blood supply, such as anterior and posterior segment ischaemia which usually severely influence visual recovery, are rare but have been reported by several authors.1-4 It may be possible that subclinical ischaemia after retinal detachment surgery exists in many more cases than reported.5-11 Thus, the eVects of scleral buckling procedures on ocular circulation, if they exist, have important clinical implications.Studies in which the laser Doppler technique was used indicated that the pulsatile characteristics of the retinal arterial blood flow measured in the treated eyes were altered, 5 and that arterial flow rates in the major temporal retinal arteries were, on average, 50% lower in the treated eyes than in the unoperated contralateral eyes; removal of scleral buckling elements in two patients produced increases of 73% and 44% in arterial blood flow rates.6 One study using colour Doppler imaging indicated that scleral buckling procedures with encircling elements decreased average blood flow velocity in the central retinal artery by 35% on the first operative day and by 50% 1 week postoperatively but did not aVect that in the ophthalmic artery, 7 whereas another study reported that the same surgery reduced the average blood flow velocity in the ophthalmic artery by 31% 2 days after surgery. 8 In patients with rhegmatogenous retinal detachment, the ocular pulse amplitude in the surgically treated eyes was reportedly lower by 53% compared with fellow eyes 6 months after scleral buckling.11 These findings suggest that scleral buckling decreases not only retinal but also c...

Changes in Higher-Order Aberrations after Scleral Buckling Surgery for Rhegmatogenous Retinal Detachment

“…Several pre-and postoperative factors such as the long duration of macular detachment, alterations in retinochoroidal circulation, and ciliary edema have been reported to be associated with poor visual outcomes of the scleral buckling surgery. [26][27][28][29][30] Our results revealed that the mean comaand spherical-like aberrations at 3 postoperative months were 0.385 ± 0.267 and 0.271 ± 0.156, respectively. Pesudovs et al revealed that coma-and spherical-like aberrations for 6-mm pupils in patients with various types of spherical intraocular lenses (IOLs) were 0.37-0.51 and 0.36-0.60, respectively.…”

Retinal Blood Flow in the Macular Area Before and After Scleral Buckling Procedures for Rhegmatogenous Retinal Detachment Without Macular Involvement

“…12 Normal ocular blood flow in RRD has been reported in several studies, 6,7,9 but the main targets for evaluation were the central retinal artery and the ophthalmic artery 6,7 or choroidal vessels. 9 The blood-flow rate in the major superior and inferior temporal retinal arteries, which were in the attached retinas of the patients with RRD, was measured by the laser Doppler technique. 4,15 It was found to be lower than in the fellow eyes 4 or in the normal controls.…”

“…[4][5][6][7][8][9][10] The tissue blood flow in the retina or choroid has been noninvasively measured mainly by laser Doppler velocimetry, 4,5 color Doppler ultrasonography, [6][7][8] the laser speckle method, 9 and the pulsatile ocular blood flow technique. 10 However, the evaluation of the retinal blood flow in the macular area by these techniques has been difficult.…”

Microcirculation in the macular area of eyes with an idiopathic epiretinal membrane

“…In addition, attention has been focused on the changes of retinal blood flow in some retinal diseases in the attempt to understand the etiology and severity of the condition and also to evaluate the outcome of surgery [2,17].…”