Dr. Then obtained his Bachelor of Medicine, Bachelor of Surgery (MBBS) from St.George's Hospital, University of London. He also has a Masters degree in biochemistry and molecular biology from King's College, University of London. He did his basic and higher surgical training at West Midlands Region. In addition, he has done one year fellowship in stem cell research at Keele University. Dr. Then became a Fellow of the Royal College of Surgeons, Edinburgh in 1999 and is registered with the General Medical Council (U.K.) Specialist Registry. He was recommended by the UK Postgraduate Medical Education Training Board to the Royal College of Ophthalmologist, London to be awarded a certificate of completion of training (CCT) in 2006 after finishing his higher surgical training. He has done two cornea and anterior segment fellowships (Birmingham and Brighton) as well as a fellowship in inflammatory eye diseases (Birmingham). He has received numerous awards including the prestigious Scottish Priory of the Order of St.John's research fellowship, an award given by the Royal College of Surgeons, Edinburgh. He has also received numerous grants for his research including a major grant from the British Biotechnology and Biological Sciences Research Council and GUP Universiti Kebangsaan Malaysia grant.
Dr. Then has ten years of experience as an ophthalmologist in United Kingdom before being appointed as a senior lecturer/consultant ophthalmologist at Hospital Universiti Kebangsaan Malaysia. He is the head of the cornea and external eye diseases service in that hospital. Dr Then is registered in the Malaysian National Specialist Register. To date he has over 50 international presentations and over 25 publications. He is also the first ophthalmologist in Malaysia to use a patient’s tooth to save his vision, a highly complex procedure only performed by a few surgeons around the world. Apart from cataract surgeries, his other interests include corneal transplantation, pterygium surgery, complex corneal diseases, contact lens related disorders, keratoprosthesis and stem cell treatment for corneal stem cell deficiency.