The primary academic interest of Prof Tham lies in angle closure glaucoma, as well as the laser and surgical treatments of glaucoma. Prof Tham′s earlier work established a role for argon laser peripheral iridoplasty in the treatment of acute primary angle closure and other forms of angle closure glaucoma. More recently, his randomized controlled trials provided insight into the roles of lens extraction and other glaucoma surgeries in both acute and chronic primary angle closure glaucoma eyes. Prof Tham was a member of the research consortium that identified the first genetic mutation associated with primary angle closure glaucoma.