The social media revolution has even spread to the perhaps over-cautious Ophthalmology market. According to ASCRS's Eyeworld, ophthalmologists are experimenting with Facebook and YouTube channels.

But don't get too excited. Ophthalmology-sponsored patient communities are a long way from being ubiquitous on the internet. The industry still can't quite get its collective head around the removal of the "learned intermediary" and is definitely not ready to turn a supply of drug information and advice over to the patient community.

So what good is social media to the ophthalmology sector? Well if we leave marketing and patient education to one side, and assume that there's no real value in a "Texas Hold Em" tournament on Facebook, professional networking surely remains the most exciting Web 2.0 activity for ophthalmologists.

Dominating the online professional networking space is LinkedIn, the world's largest network with over 35 million members worldwide, 9 million of them in Europe.

The LinkedIn site is basically a database of individual profiles. Users are provided with the tools to manage and maintain their profile, connect to others on the network, share knowledge, expertise and potential opportunities.

"The subject matter of LinkedIn is the individual. While people talk about their companies and products, the main thing that you'll find with the site is people," says Steven Tylock, author of The Linkedin Personal Trainer.

Tylock explains that LinkedIn helps bridge one-to-one introductions that may lead to any number of activities and that the real benefit of online networking is the way it extends the networker's reach.

"You would never call 200 people to ask if they know anyone at XYZ Company. It just isn't practical," says Tylock. "It is easy to search through that many people on LinkedIn; then you are calling one person to ask them to introduce you to their contact at XYZ Company."

Bucking broader recessionary trends, LinkedIn is expanding internationally. Earlier this month it added a dedicated German site to service 500,000 German users already registered. The company launched sites in France and Spain last year.

LinkedIn's main rival in Europe is Xing, the German networking site formerly known as OpenBC (Open Business Community). Xing has 6.5 million users, but with most of its users in Germany and Austria, it appears to be struggling somewhat against Linkedin's global dominance. The good news for Xing users is that the cash-positive business has a new CEO and he has been tasked to pursue a more aggressive international expansion strategy with a fighting fund of $50 million at his disposal. Watch this space.

For the time being, however, LinkedIn is where it's at for international ophthalmology; the sheer size of the LinkedIn network is staggering. ?

What do you do once you find people though? "Because LinkedIn is such a personal space it can be difficult to approach people and difficult for them to realise the benefit of connecting with you," says Matt Rhodes, head of Client Services at London-based social media agency, FreshNetworks.

"This is where online communities really come to the fore, says Rhodes. "Whilst social networks are about 'me', online communities are about 'us'. Profiles and personal connections take second place to a shared idea, interest, focus or topic of discussion."

Rhodes says this is where LinkedIn's groups function comes into play. "Although LinkedIn is primarily a social network, a 'me' space based on profiles, the groups facility allows more of the 'us' networking that you get from an online community."

A quick search of ophthalmology related groups on LinkedIn turns up 17 totalling around 2810 members, perhaps demonstrating that this arena is still niche at present, but growing. Another 19 appear under eye care, ranging from optometrists to volunteer groups.

Curing eye diseases is a truly honourable goal, but the most common real-world outcome on LinkedIn is a new job.