24th Seah Cheng Siang Lecture: Seeing better, doing better--evolution and application of gastrointestinal (GI) endoscopy.

Gastrointestinal (GI) endoscopy has evolved tremendously from the early days when candlelight was used to illuminate scopes to the extent that it has now become an integral part of the practice of modern gastroenterology. The first gastroscope was a rigid scope first introduced by Adolf Kussmaul in 1868. However this scope suffered from the 2 drawbacks of poor illumination and high risk of instrumental perforation. Rudolf Schindler improved on this by inventing the semiflexible gastroscope in 1932. But it was Basil Hirschowitz, using the principle of light conduction in fibreoptics, who allowed us to "see well" for the first time when he invented the flexible gastroscopy in 1958. With amazing speed and innovation, instrument companies, chiefly Japanese, had improved on the Hirschowitz gastroscope and invented a flexible colonoscope. Walter McCune introduced the technique of endoscopic retrograde cholangiopancreatography (ERCP) in 1968 which has now evolved into a sophisticated procedure. The advent of the digital age in the 1980s saw the invention of the videoendoscope. Videoendoscopes have allowed us to start seeing the gastrointestinal tract (GIT) "better" with high magnification and resolution and optical/digital enhancements. Fusing confocal and light microscopy with endoscopy has allowed us to perform an "optical biopsy" of the GI mucosa. Development of endoscopic ultrasonography has allowed us to see "beyond" the GIT lumen. Seeing better has allowed us to do better. Endoscopists have ventured into newer procedures such as the resection of mucosal and submucosal tumours and the field of therapeutic GI endoscopy sees no end in sight.