This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diagnosis and Treatment of Retina, Subject name: Ophthalmology
[{'content': 'Veepofrin Dye is used in: \nSelect and explain. \nA. Fluoresceina Angiography, B. Indocyanin Angiography, C. Photodynamic therapy, D. All', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Veepofrin dye is used in photodynamic therapy. Photo Dynamic Therapy Choroidal Neo Vascular (CNV) membrane secondary to wet ARMD. New or recurrent subfoveal CNV Predominantly classic Lesion <5400 in Greatest Linear Diameter Primary ocular histoplasmosis syndrome. Pathological Myopia. Photodynamic therapy (concept) Involves injection of photosensitizing drug Two step, out patient procedure , I/V photo active drug | Complexes with LDL present in blood | Complex accumulates in choroidal neovascular lesions |After 15 minutes of IV inj. Activation of drug by non thermal (689nm) light in presence of oxygen | Formation of free radicals-cytotoxic, Singlet oxygen species | | Platelet activation Direct cytotoxicity | Neo-vasculature thrombosis Photodynamic therapy: Technique (PGI potential question) Photosensitising dye (Veeporfin) 6 mg/m2 BSA (30 ml) I.V. over 10 minutes. Diode laser at 689 nm, Slit lamp delivery system designed to deliver 50 J/cm2 Intensity of 600 mW /cm2 Over 83 seconds, Advantages High selectivity and no to minimal collateral damage. Temperature rise is only 2 degrees. Minimal side effects: Infusion related back pain. Extravasation and phototoxic reactions Visual disturbances, eye pain, RPE tears Visual field defects. Disadvantages Expensive Protective clothing/eye protection after treatment for five days.', 'role': 'assistant'}]