Prof MacKay offers general adult and paediatric ear, nose, throat and head and neck assessment and surgical services. He completed his medical degree at the University of NSW in 1998, graduating with honours. His Fellowship in Otolaryngology and Head and Neck Surgery was completed in 2006. In 2007 he completed a Fellowship in Airway Reconstruction Surgery for Snoring and Obstructive Sleep Apnoea, at the time being the only surgeon in NSW to do so. This Fellowship also involved further training in Head and Neck and Laryngology (Voice).

In 2008 Prof MacKay started the Illawarra Multidisciplinary Sleep Apnoea Team Meeting and acts as the Chair, holding monthly patient reviews with various other specialists and allied health staff in the Rooms. He also has been an invited speaker and chair of Snoring and Sleep Apnoea panels nationally and internationally. He is a widely recognised surgeon for sleep apnoea and snoring after his fellowship mentor, Dr Samuel Robinson.

Prof MacKay has been actively involved in the formation of a joint Head and Neck Cancer Meeting fortnightly at the Wollongong Hospital and a One Airway Clinic (with Dr Andrew Jones, respiratory physician, and Margaret Le Lacheur, speech therapist), held at the rooms.

He is actively involved in teaching as both Professor and Examiner at the University of Wollongong Medical School. He is a member of the Australasian Sleep Association and its clinical committee.