1. Singapore Eye Research Institute; 11 Third Hospital Avenue Singapore 168751 Singapore
2. Institute of Materials Research and Engineering; A * STAR (Agency for ScienceTechnology and Research); 2 Fusionopolis Way, Innovis, No. 08-03 Singapore 138634 Singapore
3. Faculty of Science, Health, Education and Engineering; University of the Sunshine Coast; Maroochydore DC Queensland 4558 Australia
4. Department of Materials Science and Engineering; National University of Singapore; 9 Engineering Drive 1 Singapore 117576 Singapore