Technology

Technology used with eye laser surgery

AVC is Harley Street's leading independent Laser eye surgery clinic. Established in 2002, the treatment centre has gained a reputation for unsurpassed levels of surgical expertise and patient care under the personal direction of the Medical Director and consultant refractive surgeon, Mr. C.T. Pillai.

AVC uses only the very latest surgical techniques, including the Bausch and Lomb Technolas z100 Laser, Zyoptix wavefront, Advance Wavefront systems with iris recognition and Staar ICL, all enabling us to offer our patients fully bespoke surgery. As a recognised Bausch and Lomb Centre of Excellence, we are able to treat a wide range of prescriptions and ensure clinical precision at all times.

The clinical team at AVC has also achieved the following:

• Medical Director Mr. C.T. Pillai was the UK's first surgeon to perform bi-lateral Laser surgery
• AVC was one of the first clinics in the UK to use Technolas (Bausch & Lomb) Zyoptix Wavefront technology
• AVC remains the only clinic in the UK to use a transparent theatre where friends and family may watch surgery live

ZYOPTIC TECHNOLOGY

Zyoptix Eye Treatment Procedure

Advanced Vision Care's Zyoptix system for personalised vision treatments uses the latest version of the Bausch & Lomb Technolas z100 Laser. It involves the use of wavefront technology in a machine called a Zywave aberrometer, along with Orbscan, to scan the front of your cornea and produce a detailed map of any irregularities that are specific to your eye. Zyoptix is available to all suitable patients, because it offers superior quality of vision compared to standard LASIK. This Laser has been specifically designed for customised Laser eye treatments and consistently achieves a high standard of vision.

The additional diagnostic screening benefits of wavefront technology has allowed our patients an improved selection and Laser eye treatment that can be personalised to a level never imagined before. Zyoptix provides the surgeon with much more detailed information on which to base decisions about your treatment, which means that Laser eye treatment is now unique to each eye.

How it works

Wavefront was first developed by astrophysicists, and has now been applied to Zyoptix. It provides the most technologically advanced measurement not just of standard visual but also of scattered light errors known as 'aberrations'. Zyoptix software combines data from two different types of diagnostic equipment, then programmes the Laser with your unique treatment, based on this data. Data is collected to assess the structure of your cornea (called topography). Data is also collected from a measurement of your optical system using the advanced wavefront technology - a measurement not normally taken with Standard LASIK treatments.

Aberrometry

Wavefront technology, or aberrometry, is based on the principle that if an eye had no imperfections at all, light passed through it would not scatter. But because no eye is perfect, light scatters to form distinct patterns - called a wavefront. Wavefront technology measures personal/individual patterns and thus allows the surgeon to plan a treatment that exactly matches individual vision errors. Your wavefront will be measured by the market-leading aberrometer, the Zywave Aberrometer from Bausch & Lomb. The Zywave aberrometer measures the eye from the centre to the outer edges (the periphery) of the pupil. This is especially important, because at night your pupils open up (dilate) and more light is scattered in the periphery of the pupils.

Topography of Cornea

The Orbscan IIz topographer analyses the physical shape/contours of your cornea and allows our surgeon to decide if it has a suitable shape, and is healthy and thick enough for treatment. It is the only topographer currently available that measures the shape of both the front and back surface of the entire cornea (other systems only measure the front surface) and can therefore provide a complete picture of the thickness of cornea. The Orbscan IIz is able to provide such high precision information as it captures data within seconds from 9000 points on the cornea during each.

ADVANCED WAVEFRONT TECHNOLOGY

This is the latest technology available to treat vision correction.

Wavefront treatment is personalised by not only correcting your prescription but also aberrations or imperfections which occur naturally in your eyes. Each treatment is unique and results in a superior quality of vision.

ZYOPTIX Advanced Personalized Technologies (APT) are a recent group of enhancements that make the Zyoptix platform even more efficient and precise in outcome. Advanced Vision Care uses true waverfront technology unlike other clinics which are using "Wavefront optimised (cheaper price)". This is not same as wavefront as it does not correct the imperfections in the eye which cause night vision problems.

Advanced Vision Care has obtained the latest Wavefront technology: Zyoptix from Bausch and Lomb. The system used generates the Wavefront map, which is used diagnostically for initial consultation and post-operative analysis to ensure the best possible treatment is provided. Sophisticated software will then convert the wavefront map into a unique treatment prescription, which in turn will be electronically transferred to a computer controlling the Laser itself.

• Patients experience a higher quality of vision i.e. contrast (black on white) is more defined, than with standard LASIK.
• Patients may experience better vision in poor lighting, twilight, or for night driving.
• The recovery time to good vision is often more rapid than with standard LASIK.
• Wavefront technology removes less corneal tissue, meaning more patients with thinner.
• corneas may be able to be treated than with standard LASIK. It is also therefore able to treat.
• higher prescription safer and more accurately.

It is important to note that the aim of this treatment is not to improve detail of vision beyond that achieved with glasses (i.e. lines on the vision chart), but the overall quality of vision when compared to standard treatment.

Improved Quality of Vision

In low lighting conditions our pupils expand (or 'dilate'). Research shows that there are more 'aberrations' or optical imperfections at the outer edges (periphery) of the pupil. This results in a distortion of the light entering the eye. As a result, it is possible to be able to look at a round light source in the distance, but instead of seeing a perfectly round shape, you will see an irregular image. This distortion of light reduces the quality of our vision and explains one of the reasons why many patients experience difficulty with their vision when driving at night.

Zyoptix treatments have been designed to remove these optical imperfections, improving not just what we see, but the quality of how we see objects. 97% of patients reported a marked or extreme improvement in their quality of vision. 98.2% of patients said they would have a Zyoptix treatment again

What results can you expect?

Significantly more Wavefront patients in this study experienced improved results with their vision when driving at night than patients who had received standard Bausch & Lomb LASIK eye surgery.

Night Driving

More than 8 out of 10 Wavefront patients in this study reported same or better quality of vision in various common light conditions. 90.7% of patients reported the same or fewer difficulties with night driving.

Excellent Visual Acuity

Zyoptix produces a better quality of vision as well as excellent visual acuity results. In this recent FDA approved trial, 91.3% of patients achieved 20/20 (6/6) vision without any correction 6 months after the treatment. 99.4% of patients achieved 20/40. 70.3% of patients even achieved 20/16 vision without any glasses or spectacles, which is an improvement over the accepted standard of 20/20 vision.

Eye Tracker

Multi-dimensional Rotational Eyetracker

At Advanced Vision Care, we use sophisticated Multi-dimensional Eyetracking Technology to detect the positional changes of the eyes, ensuring the patient's safety is maintained throughout the procedure. Our state-of-the-art Laser, the Bausch and Lomb z100, and the Eyetracking Technology used at Advanced Vision Care enables us to deliver the highest quality and most accurate corrective eye surgery available today.

What is the Eye-Tracking Procedure?

During surgery the patient is asked to look directly at a red light, and the video-based infrared camera communicates the information back to a computer to verify the positioning of the eye. The Laser is adjusted accordingly before a pulse is fired. This is called a closed loop system, and is extremely sophisticated. The eye tracker is also both passive and active in its mechanism. This means that a certain range of eye movement will be compensated for (3mm), but beyond this amount of movement, the Laser will cease to deliver a pulse. This provides a safety-lock mechanism to prevent any failures and also guarantees that the patient's safety is maintained at all times. It means there is no need for concern about eye movements affecting vision.

The new Multi-Dimensional Eyetracker on the Zyoptix z100 system has a few additional features. Whilst it still compensates for the undetectable small movements and/or stops Laser from firing when the movement is too large and target becomes out of range, it also offers a faster reaction time of 6.6 milliseconds. It also has the ability not only to track movements in the horizontal (x-plane) or vertical (y- plane) dimension, but also in the 3rd dimension (z-plane) and the ability to compensate for more complex movements of the pupil and eye. In a small number of cases, pupils dilate/open up unevenly or eyes turn off-axis when you lie flat. The Eyetracker compensates for this automatically.

IRIS RECOGNITION

When performing Laser treatment it is critical that natural eye movements do not adversely affect the outcome. Like the fingerprints, no two irides are the same and they can therefore be used to provide a unique identification. The new Zyoptix z100 system has an exceptional feature that scans the irides during the Zywave measurement and maps the entire iris, generating a unique digital Zy-ID for each eye. This map of the iris forms the foundation from which the Advanced Control Eyetracking (ACE) technology operates. This highly sophisticated safety device tracks minute eye movements and guides the Laser to follow them.

During treatment, the eyes make natural small movements (in the horizontal, vertical and the third dimension) almost undetectable to the human eye. The Eyetracker ensures that the Laser follows these small movements in the x, y and z plane. The tracker also has the ability to compensate for more complex movements such as pupil shift (uneven dilation/opening of the eyes) and cyclotorsion (off- axis turn of the eyes). If the movements are too large for the Laser to place the beam accurately, the Eyetracker will force the Laser to stop until the eye is in the correct position again. The very fast reaction time (6.6 milliseconds - faster than a human blink) ensures that every Laser pulse stays focused and is placed precisely where it should be to accurately reshape the cornea.