Vascular effects on ciliary tissue from endoscopic versus trans-scleral cyclophotocoagulation

Abstract

Chronic poor perfusion of the ciliary body after TCP may account, in part, for its efficacy, as well as the significant complications including hypotony and phthisis. Late reperfusion of this region after ECP may provide some insight into the differences in efficacy and complication rates compared to TCP.

Surgical Treatment of Canine Glaucoma

“…47,48 Studies that describe histopathologic changes of the CB after treatment with ECP in other mammal species consistently report ciliary epithelium damage, sparing damage to the ciliary stroma, ciliary muscle, and adjacent tissue, unlike what has been shown with TSCP. 12,49,50 However, histologic studies of the chronic changes in the CB in dogs after ECP treatment are still lacking.…”

“…Possible undesired consequences such as marked disruption of the ciliary epithelium with severe architectural damage to the ciliary muscle, stroma, and adjacent sclera, and acute occlusive vasculopathy (in some cases permanent nonperfusion), have been reported. [12][13][14][15] There is agreement that the amount of energy delivered is correlated with tissue destruction and inflammation, and with postoperative complications. Balance between desired tissue destruction for adequate IOP control and overtreatment is the ideal surgical goal, although sometimes difficult to attain.…”

“…Thermal damage is also responsible for vascular occlusion or nonperfusion of the ciliary processes (CPs). 12 The applied laser energy is well absorbed by uveal melanin, resulting in blanching, shrinking, and thereby damage to the secretory ciliary epithelium of the CP that produces aqueous humor.…”

Endoscopic and Transscleral Cyclophotocoagulation for the Treatment of Refractory Glaucoma

“…62,63 Two studies have compared the histologic effects of TCP and ECP. 64,65 Lin et al 64 studied the acute and late effects of diode TCP and ECP on the histology and ciliary blood flow in rabbits. TCP caused severe disruption of the ciliary processes and iris root, and substantial reduction of their blood flow up to 1 month after treatment (Fig.…”

Endoscopic and transscleral cyclophotocoagulation

“…2 They have attempted to quantify the evolution of vascular changes following CP; their results demonstrate that both TSCP and ECP are associated with an acute occlusive vasculopathy, but that with the endoscopic modality the chronic underperfusion is less than with the transscleral route.…”