This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Ophthalmology
[{'content': 'Astigmatism in emmetropic eye of elderly person contribute to: \nSelect and explain. \nA. +1d, B. +2D, C. +3D, D. +4D', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Laser vision enhancements When planning presbyopia-correcting IOL(Intra ocular lens) surgery in a patient with a high level of pre-existing astigmatism (ie, more than 3 D), a bioptics approach (ie, IOL followed by laser vision enhancement) may be needed. LRIs alone are unlikely to correct the astigmatism completely.Limbal Relaxing Incisions (LRI) are a refractive surgical procedure to correct minor astigmatism in the eye. There are several different strategies for these planned laser vision enhancements. The first is to perform the presbyopia-correcting IOL surgery followed by LASIK or PRK. REF : AK KHURANA 7TH ED', 'role': 'assistant'}]