The best prevention is to use organic Jojoba oil as your daily facial moisturizer and salicylic acid toner 2% to ensure exfoliation.

Use of pore strips weekly also helps remove whiteheads and blackheads which cause the sebaceous glands to go into hypertrophy because they are blocked.  They then get larger and require more blood so the blood vessels increase in the area and because the pores are blocked fibrous connective tissue forms.