The EYESI surgical simulator uses instruments that function just like the actual ones.

Eye surgery calls for a technically demanding skill. The surgeon must master the technique of using both hands and both feet in a coordinated manner to control microscopic instruments, the microscope and the vitrector system — all this while working on the most delicate tissues of the human body so that unnecessary damage is avoided.

But some help is at hand for would-be eye surgeons. They can now be trained by an EYESI surgical simulator that uses advanced computer technology and virtual reality to simulate the feel of real eye surgery. A recent addition to the pool of training resources engaged by ORBIS International, the EYESI surgical simulator was created in 2002 by VRMagic Technology Group, a German company that specialises in image processing and display technology. The EYESI makes it possible for surgeons to acquire new skills and to perfect their techniques in preparation for surgery on the human eye.

Says Dr Eugene Helveston, ophthalmologist in chief, ORBIS International, “The EYESI is one of the few microsurgery simulators currently available that precisely mimics the actual confines, including multiple layers, structures and conditions inside an organ. It is unique in that it essentially invites the user inside the eye and allows the surgeon to carry out precise manipulations.”

ORBIS International is a non-profit organisation which works to eliminate avoidable blindness in developing nations where 90 per cent of the world’s blind population lives. It is a founding member of Vision 2020, a global initiative led by the World Health Organisation and the International Agency for the Prevention of Blindness, that aims to end avoidable blindness by 2020.

During simulated surgery, the surgeon uses instruments that function just like the actual ones, and the view through the microscope is similar to that through the surgical microscope. The results of the surgery are not predefined but depend on the way the surgeon functions. Tissue reaction is individually computed in each training session, making it possible to assess the surgical ability of each trainee doctor. Simulation thus provides a stress-free environment for doctors in training so that despite the errors that may crop up, confidence and competence are enhanced.

The trainee sits at the controls looking through the stereo operating scope that peers down on two separate images of the operating field. Each image is specific for the view from either eye. The Silicon Graphics computer is responsible for the visual rendering of the images displayed on the monitor. The surgeon interacts with a virtual eye using a virtual surgical instrument controlled by a handheld 3-D position-tracking stylus that continuously reports the position and orientation to the computer. The tip of the stylus is connected to three motors that generate component force feedback in response to the tool-tissue interaction.

Traditionally, young surgeons learn these skills during residency and fellowship training, using the eyes of pigs or cadavers. This phase is followed by assisting experienced surgeons and eventually, fellows and residents perform surgery on actual patients.

“Our latest training tool will be in India in March 2007 during a Flying Eye Hospital programme in Mumbai,” says Brooke Johnson of ORBIS’ communications department, New York. “The EYESI surgical simulator is particularly effective for introducing intraocular surgery to younger doctors and students,” says Helveston.

While the hardware of the simulator is phenomenal, the software has scope for much improvement and this has opened up the floodgates for universities and research organisations developing and selling software to be used in conjunction with the EYESI simulator hardware.

Since 1988, Orbis has conducted 14 Flying Eye Hospital programmes and more than 100 hospital-based training events in subspecialties of ophthalmology in India. The ORBIS India programme now also includes numerous childhood blindness projects, eye health financing, enhancement of management skills at eye hospitals and a project dedicated to furthering the Vision 2020 Plan of Action for India.

Santosh Das, 6, son of a Bihari daily labourer, was visually impaired. But luck smiled on him last year when he was chosen as one of the beneficiaries for an operation organised by ORBIS’ Flying Eye Hospital training programme in Calcutta.

Dr G V Rao, country director, ORBIS India, recalls the programme as a successful event focusing on childhood blindness and eye banking. “More than 350 eye care professionals participated in it. Over 150 patients were examined for eye conditions and 61 of them received free eye surgeries.”

Dr Rao also notes: “Despite India being the first country to initiate a government programme to manage blindness (National Programme for Control of Blindness, 1976), the project for three decades focused only on age-related cataract. Intensive lobbying by ORBIS, Vision 2020 and other blindness prevention agencies has resulted in the government acknowledging that childhood blindness should be an area of immediate priority.”