Final answer:
ICD 9 regular unspecified astigmatism is a classification code used to record a type of astigmatism that is not specified further in terms of its severity or axis. It indicates an irregularly shaped cornea or lens causing distorted or blurred vision, usually corrected with eyeglasses.
Step-by-step explanation:
ICD 9 regular unspecified astigmatism refers to a classification code used for medical record-keeping and insurance billing. ICD-9 (International Classification of Diseases, 9th Revision) is an old coding system that has been replaced by ICD-10. In this case, 'regular unspecified astigmatism' indicates a type of astigmatism that is not specified further in terms of its severity or axis.
To understand astigmatism, it is important to know that it is an eye condition characterized by an irregularly shaped cornea or lens, which causes distorted or blurred vision. Regular astigmatism refers to a condition where the axis (orientation) of the astigmatism is either 90 degrees or 180 degrees.
An eyeglass prescription with a cylindrical correction is used to correct astigmatism. If the astigmatism is not specified further, it means the severity or axis is unknown or has not been specified in the diagnosis.