If a 37-year-old RP patient has an initial total point score of 900 db and receives the implant treatment, what is the probability that the patient will become legally blind by age 50? 

Suppose a new treatment is discovered based on ocular implants. The treatment immediately lowers total point score by 50 db. However, the long-term effect is to reduce the mean rate of decline to 25 db per year (from the previous 45 db per year), while maintaining the same variance of change as previously (that is, variance of change over N years = 1225N).