First of all, I want to make it clear that no one can guarantee improvement of pores. However, after more than 20 years of trying different treatments, including topical creams, V-beam, Smoothbeam, Carbon Dioxide lasers, chemical peels, dermabrasion, and microdermabrasion, I have found that, in my hands, the only treatments that sometimes improves the size of pores are the Clear and Brilliant and the Fraxel Restore lasers. Both lasers require several treatments, usually 5 or 6, done every three to four weeks. Clear and Brilliant is less uncomfortable and there is less down time than the Fraxel Restore, which is not bad compared with the Fraxel Repair carbon dioxide laser, the latter which is not recommended by me for improvement of pores. One additional treatment that I find can improve pores is the nitrogen plasma resurfacing device originally from Rhytec, now an Energist device. The plasma energy can be altered to design treatment customized for the patient's ability to undergo down time. The lightest PSR I treatment can help temporarily, rarely permanently, shrink the pores.
Regardless of laser or plasma, please realize that pores are a necessary structure of the skin. One can not eliminate them entirely except for skin that heals after traumatic injury such as a kitchen grease burn, with scarring in which the pores are not visible. Some people who need acne treatment notice that there pores look more noticeable because initially they were plugged causing the acne but once the pores are cleaned out of sebum (oil) and dead skin cells, there is less acne formation but the pores look more open and visible.
The information provided in Dr. Shelton's answer is for educational purposes only and is not intended to constitute medical advice. The information provided should not be relied upon as a substitute for consultations with a qualified health professional who may be familiar with your individual medical needs.
Web reference: http://www.thenyac.com/clear-and-brilliant/index.html