APTOS 2019, the 4th annual symposium of Asia Pacific Teleophthalmology Association was organised by Aravind Eye care System at ITC Grand Chola, Chennai. The theme of the 4th APTOS Symposium was the Evolution of AI in Ophthalmology and its impact in Teleophthalmology and Innovative Service Delivery. Another highlight of APTOS 2019 was the Hackathon and the Big Data DR Challenge for different algorithms in ocular diagnostics. The symposium was very well-received with a total of 316 participants which included medical specialists, ophthalmologists, engineers, students of medicine and engineering from colleges all around the world. Experts from the field of AI, telemedicine, information technology and ophthalmology from Australia, United States, Singapore, United Kingdom, Thailand, Switzerland, Chile, China and India delivered interesting lectures.