Purpose: To assess the ability of the Preferential Hyperacuity Perimeter (PreView PHP; Carl Zeiss Meditec, Dublin, CA) to detect recent-onset choroidal neovascularization (CNV) resulting from age-related macular degeneration (AMD) and to differentiate it from an intermediate stage of AMD. Design: Prospective, comparative, concurrent, nonrandomized, multicenter study. Participants: Eligible participants’study eyes had a corrected visual acuity of 20/160 or better and either untreated CNV from AMD diagnosed within the last 60 days or an intermediate stage of AMD. Methods: After obtaining consent, visual acuity with habitual correction, masked PHP testing, stereoscopic color fundus photography, and fluorescein angiography were performed. Photographs and angiograms were evaluated by graders masked to diagnosis and PHP results. The reading center’s diagnosis determined if the patient was categorized as having intermediate AMD or neovascular AMD. Main Outcome Measures: A successful study outcome was defined a priori as a sensitivity of at least 80%and a speci-ficity of at least 80%. Results: Of 185 patients who gave consent to be enrolled, 11 (6%) had PHP results judged to be unreliable. An additional 52were not included because they did not meet all eligibility criteria. Of the remaining 122 patients, 57 had an intermediate stage of AMD and 65 had neovascular AMD. The sensitivity to detect newly diagnosed CNV using PHP testing was 82%(95%confidence interval [CI], 70%-90%). The specificity to differentiate newly diagnosed CNV from the intermediate stage of AMD using PHP testing was 88%(95%CI, 76%-95%). Conclusions: Preferential Hyperacuity Peri-meter testing can detect recent-onset CNV resulting from AMD and can differentiate it from an intermediate stage of AMD with high sensitivity and specificity. These data suggest that monitoring with PHP should detect most cases of CNV of recent onset with few false-positive results at a stage when treatment usually would be beneficial. Thus, this monitoring should be considered in the management of the intermediate stage of AMD. Purpose: To assess the ability of the Preferential Hyperacuity Perimeter (PreView PHP; Carl Zeiss Meditec, Dublin, CA) to detect recent-onset choroidal neovascularization (CNV) resulting from age-related macular degeneration (AMD) and to differentiate it from an intermediate stage of AMD. Design: Prospective, comparative, concurrent, nonrandomized, multicenter study. Participants: Eligible participants’ studying eyes had a corrected visual acuity of 20/160 or better and either untreated CNV from AMD diagnosed within the last 60 days or an intermediate stage of AMD. Methods: After obtaining consent, visual acuity with habitual correction, masked PHP testing, stereoscopic color fundus photography, and fluorescein angiography were performed. Photographs and angiograms were evaluated by graders masked to diagnosis and PHP results. if the patient was categorized as having intermediate AMD or neovascular AMD. Main Outcome Measures: A successful study outcome was defined a priori as a sensitivity of at least 80% and a speci-ficity of at least 80%. Results: Of 185 patients who gave consent to be enrolled, 11 (6%) had PHP results judged to be unreliable. An Of the remaining 122 patients, 57 had an intermediate stage of AMD and 65 had neovascular AMD. The sensitivity to detect newly diagnosed CNV using PHP testing was 82% (95% confidence interval [CI], 70% -90%). The specificity to differentiate newly diagnosed CNV from the intermediate stage of AMD using PHP testing was 88% (95% CI, 76% -95%). Conclusions: Preferential Hyperacuity Peri-meter testing can detect recent-onset CNV resulting from AMD and can differentiate it from an intermediate stage of AMD with high sensitivity and specificity. These data suggest that monitoring with PHP should detect most cases of CNV of recent onset with few false-positive results at a stage when treatment usually would be ben eficial. Thus, this monitoring should be considered in the management of the intermediate stage of AMD.