Abstract
Purpose: :
To report on a prospective case series of choroidal feeder vessel (VF) photocoagulation using a novel device that allows real time visualization and treatment of FV (OPTTx, Novadaq, Canada).
Methods: :
Patients attending a tertiary referral choroidal neovascularization (CNV) clinic were assessed according to a standardized protocol inclusive of refracted logMAR visual acuity, fundus fluorescein angiography (FFA), and high-speed indocyanine green video angiography (HS-ICGA) (HRA, Heidelbergh Engineering). CNVs were scrutinized for the presence of extrafoveal FV suitable to laser photocoagulation. Fourteen eyes of 14 patients with treatable FV underwent a further diagnostic ICGA at the novel device to verify FV visualization. Verified FV were directly targeted with the in-built 810nm laser to attempt FV closure. This was done during the choroidal transit of a "treatment ICGA" whereby a higher concentration I.V. ICG bolus (18.75mg/0.3cc) was administered to both visualize the FV and to enhance selective laser uptake. Post-treatment FFA and HS-ICGA to check FV closure and CNV status were carried out on the same day and at follow up (range 1-9 months).
Results: :
Of 14 eligible eyes 13 had CNV secondary to AMD and one associated to a toxoplasmic scar. In 9 (64%) eyes a FV could be identified and treated with the novel device. In 4 (28%) eyes the FV could not be verified at the novel device or could not be targeted with the in-built laser. In 1 eye a normal choroidal vessel was mistaken as FV and lasered with no ensuing vessel closure. Immediate FV closure was achieved in 7 (77%) of 9 treated eyes. The FVs reopened between 1 and 3 months in all eyes with wet AMD although the CNV size and leakage were reduced in 4 (57%) eyes. FV closure persisted up to the 9 month follow up in the toxoplasmic CNV. Improvement of 1 or more lines of visual acuity occurred in 4 (57%) of 7 eyes that exhibited FV closure at their review. There were no adverse events. Familiarization with the procedure increased the FV closure rate, with 4 out of 5 failed FV treatment attempts occurring in the first 6 months of use of the device.
Conclusions: :
After an initial learning curve feeder vessel closure was feasible, safe, and relatively easy using a real time visualization and treatment device. Short term FV closure and reduction of CNV size could be achieved in the majority of AMD cases. Longer term benefit may be achieved in non AMD CNV.
Keywords: age-related macular degeneration • choroid: neovascularization • retina