You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Outcome", "Participant", "Intervention"].

Please return the output as a JSON object of the format: {"Participant" : ["patients with COPD", ...], "Intervention" : ["Atenolol", ...], "Outcome" : ["blood pressure", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Can HMG Co-A reductase inhibitors ( " statins " ) slow the progression of age-related macular degeneration ? The age-related maculopathy statin study ( ARMSS ) . Age-related macular degeneration ( AMD ) is responsible for the majority of visual impairment in the Western world . The role of cholesterol-lowering medications , HMG Co-A reductase inhibitors or statins , in reducing the risk of AMD or of delaying its progression has not been fully investigated . A 3-year prospective randomized controlled trial of 40 mg simvastatin per day compared to placebo in subjects at high risk of AMD progression is described . This paper outlines the primary aims of the Age-Related Maculopathy Statin Study ( ARMSS ) , and the methodology involved . Standardized clinical grading of macular photographs and comparison of serial macular digital photographs , using the International grading scheme , form the basis for assessment of primary study outcomes . In addition , macular function is assessed at each visit with detailed psychophysical measurements of rod and cone function . Information collected in this study will assist in the assessment of the potential value of HMG Co-A reductase inhibitors ( statins ) in reducing the risk of AMD progression .
{"Intervention": ["40 mg simvastatin per day", "placebo", "HMG Co-A reductase inhibitors or statins", "HMG Co-A reductase inhibitors ( \" statins \" )", "HMG Co-A reductase inhibitors ( statins )"], "Outcome": [], "Participant": ["age-related macular degeneration", "AMD", "Age-related macular degeneration ( AMD )"]}