Around 10 billion contact lenses are produced each year and the humble contact lens has been one of Australian research’s great success stories, with one of the world’s most popular lenses first developed through the CRC Program.
The seemingly simple, flexible material took around 20 years of research to develop, but it helped launch a new era in contact lens wear and brought hundreds of millions of dollars in royalties to its inventors. The benefits to Australia have been immense – investment in further research, as well as education and public health initiatives – with us now recognised as a leading country in the vision research and the eye care field.
The silicone hydrogel contact lens material, created by researchers in the Cooperative Research Centre for Eye Research and Technology (CRCERT), based in Sydney, first launched by CIBA VISION in 1999 as the Focus® Night & DayTM lens was the first contact lens to be FDA-approved for continuous wear of up to 30 days. Lenses made from materials like these now account for around 50% of soft contact lens sales in the U.S.
Contact lenses had already come a long way since the first hard corneal lenses were taken up by wearers in the 1950s. Soft contact lenses were synthesized in the late 1960’s allowing many more people to achieve comfortable fittings. However, early contact lenses restricted the oxygen flow to the cornea (normally supplied by tears and directly from the atmosphere), leading to the condition hypoxia which particularly when worn overnight, carried the risk of corneal swelling (edema) resulting in hazy vision and potentially more serious corneal problems.
By the early 1990’s the risk to the ocular surface associated with hypoxia while wearing soft contact lenses was recognised as being a barrier that needed to be overcome. This breakthrough lens, which was made from a silicone hydrogel material known as ‘Lotrafilcon A’, increased the supply of oxygen to the eye during contact lens wear to sufficient levels to prevent hypoxia.
When first released, the lens was hailed as a major breakthrough as it provided all the advantages of other soft lenses on the market at that time, particularly in relation to wettability and wearer comfort but it had the significant added bonus of greater oxygen transmissibility.
How it all happened
Professor Holden along with colleague Dr George Mertz at the University of New South Wales in Sydney, had laid the groundwork for this future research when they completed a study back in 1978, which identified the minimum amount of oxygen the eye needs to prevent overnight corneal swelling.
CRCERT was part of the Australian Government’s CRC Program, established in 1991 to forge partnerships between researchers and industry and promote Australian innovation. Led by Professor Brien Holden, Director of CRCERT, and Dr Adrian Hunter from CIBA VISION, CRCERT brought together what was the largest multidisciplinary, multinational collaboration of scientists in this field at the time.
The CRCERT team included biomedical engineers and biologists, polymer chemists, clinical scientists and material scientists and one of its key researchers was Dr Arthur Ho, the project co-ordinator for what became known as the SEE3 study. According to Ho, the name of the study originated over dinner with representatives from the three lead organisations – the Cornea and Contact Lens Research Unit (CCLRU), Ciba Geigy (which later became Novartis) and CIBA VISION, each name beginning with ‘C’, but when written down it was spelt phonetically.
“SEE3 involved 80-90 individuals working across eight locations and multiple time zones – which, in the days before video conferencing and cloud computing provided another challenge to be overcome,” Ho said.
Despite various attempts, it proved impossible to reduce the thickness or increase the water content of the hydrogel materials that were commonly used for contact lenses, to allow an adequate supply of oxygen to reach the cornea without precipitating other problems for the cornea. Silicone hydrogel lenses contain both silicone and hydrogel polymers in a structure which allows the lens to transmit higher levels of oxygen, as well as water, both of which are essential for ocular health.
Following significant work in the laboratory, potential lenses underwent animal and then human trials, feeding back invaluable results that were used to perfect the final product, which received FDA approval in the United States in 1999. As with many areas of research, a number of novel by-products also resulted, including a model eye that enabled researchers to test the wettability of prototypes.
For Ho, the excitement of the project was the thought of creating something that would be worn by the millions of people who avoided lenses because of the daily routine of insertion, removal, cleaning and storing. The continuous wear lens would open up the world of contact lenses to a huge new audience.
Over the years, CIBA VISION and the Vision CRC (the successor to CRCERT) have continued to develop the original silicone hydrogel lens to produce products including O2Optix™, Air Optix Toric™ and Air Optix Multifocal™.
“The global contact lens and solutions market will be worth over $11bn by 2015,” says Professor Brien Holden, CEO of Brien Holden Vision Institute and Vision CRC, a founder and former director of CRCERT. “Prior to the advent of silicone hydrogel lenses it was estimated there were around 80 million contact lens wearers worldwide. There are now around 130 million wearers and silicone hydrogel lenses have been a significant reason for that market growth.”