Optimizing treatment of choroidal neovacularization feeder veel aociated with age-related macular degeneration

PURPOE: To optimize the method of treating choroidal neovacularization (CNV) aociated with age-related macular degeneration (AMD). DEIGN: Experimental tudy and interventional cae erie. METHOD: The parameter aociated with locating and then photocoagulating CNV feeder veel were identified and optimized uing publihed data and data derived from modeling the choroidal vaculature. Baed on thee optimized parameter, a prototype diagnotic/treatment ytem wa deigned that capture high-peed indocyanine green (ICG) angiogram image and facilitate analyi of the image by enhancing viualization of dye movement through CNV feeder veel (FV). The ytem alo permit precie aiming and delivery of 810- nm wavelength photocoagulation laer energy to target FV on a real-time ICG angiogram image of the choroidal vaculature. Target FV are tracked by a joy-tick controlled laer aiming beam until an intravenouly-injected high-concentration ICG dye bolu i oberved to enter the target veel, at which time the laer i fired. Proof of principle of the combined diagnoi/treatment ytem deign for performing dye-enhanced photocoagulation (DEP) in the clinical etting and determination of the minimum DEP laer energy needed to cloe CNV FV wa made in 11 AMD patient requiring treatment of CNV, but for whom other treatment wa not appropriate. REULT: Uing ICG—DEP, CNV feeder veel were cloed with ingle pule laer energy, delivering a little a 0.6 to 1.8 J of energy to the fundu, producing no viible change in the fundu. ucceful FV cloure wa uually indicated immediately by preence of incarcerated ICG dye in the veel adjacent to the burn ite. The prototype ytem proved relatively eay to operate. After acquiring and interpreting diagnotic angiogram and repoitioning a patient in front of the device, feeder veel DEP and treatment evaluation required 15 to 20 minute. CONCLUION: Indocyanine green dye-enhanced photocoagulation of CNV feeder veel, facilitated by ue of a device that permit real-time viualization of the choroidal circulation while aiming the treatment laer beam, appear to minimize the amount of energy applied to the fundu and the volume of fundu tiue affected by treatment, compared with other treatment modalitie. The combination diagnoi/treatment device hould be ueful in optimizing FV treatment and in refining and evaluating the efficacy of DEP in future clinical trial.