Influence of exposure time on inflammatory response to neodymium:YAG cyclophotocoagulation in rabbits
D. A. Echelman, M. P. Nasisse, M. B. Shields, M. C. McGahan and L. N. Fleisher
Department of Ophthalmology, Duke University Medical Center, Durham, NC.
OBJECTIVE: To evaluate the influence of duration of exposure on the
inflammatory response to transscleral neodymium:YAG cyclophotocoagulation.
METHODS: Transscleral cyclophotocoagulation was performed with a contact,
Nd:YAG, continuous-wave laser on one eye of 48 Dutch belted rabbits, 10 W
and 0.2 second used in half and 1 W and 2 seconds in the other half. One
third of each group was evaluated on the operative day and the other thirds
on postoperative days 3 and 10. Tissue reaction was inspected grossly and
by light microscopy, and inflammatory responses were measured by aqueous
leukocyte and erythrocyte counts, aqueous and vitreous protein levels,
aqueous prostaglandin levels, and iris and ciliary body myeloperoxidase
activity. RESULTS: The shorter-duration protocol was associated with more
ciliary epithelial disruption and significantly greater inflammatory
responses by one or more of the measures at all times. CONCLUSION: When
energy is constant, a shorter duration of exposure with transscleral Nd:YAG
cyclophotocoagulation in rabbits is associated with greater tissue
disruption and inflammation.
