Histopathological Changes After Standard and Novel Endoscopic Cyclophotocoagulation versus Transscleral...

To compare the histological effects of a novel endo-cyclophotocoagulation (ECP) device (Leos, BVI Medical, Waltham, MA), a standard ECP (BVI Medical, Waltham, MA), and transscleral cyclophotocoagulation (TCP) on the ciliary body and processes in human cadaveric eyes.

Cross-sectional histological analysis of three cadaveric human eyes, where each laser method was used to treat a segment of the ciliary body and ciliary processes of each eye. Each treated eye was then prepared for histologic assessment by dissecting the anterior segment away from the posterior segment to isolate the ciliary processes and adjacent tissues, followed by segmenting them according to the specific treatment protocol. After fixation in blocks, 8 μm sections were prepared, dewaxed in xylene, hydrated in decreasing concentrations of ethanol, stained with haematoxylin and eosin/phloxine, and examined histologically using standard light microscopy.

Histologic examination revealed that both standard and novel ECP caused contraction of the ciliary processes and disruption of the pigmented epithelium with minimal effect on stromal architecture. TCP resulted in disruption of the ciliary body muscle, stroma, ciliary processes, and both pigmented and non-pigmented ciliary epithelium.

The novel ECP led to similar tissue changes to the standard ECP in human cadaveric eyes. TCP led to extensive tissue disruption that extended beyond the ciliary processes into the stroma and adjacent ciliary muscles, which is consistent with previous studies of TCP. Future prospective clinical studies would provide data on how the novel ECP device compares to both standard ECP and TCP in both safety and efficacy.