IntraCorneal Rings: INTACS
What Are INTACS?
INTACS inserts are clear, thin prescription inserts placed in the periphery of the cornea during a brief procedure. INTACS inserts reshape the curvature of the cornea from within, without removing any corneal tissue. INTACS inserts cannot be felt, are no more visible than a contact lens, and can be removed or replaced if needed, although this is uncommon. INTACS inserts have a valuable place in the treatment of keratoconus, pellucid marginal degeneration and corneal ectasia.
For keratoconus patients who are contact lens intolerant the goal of the INTACS procedure is to improve functional vision with contact lenses or glasses and in some cases without them. The INTACS procedure does not prevent the eye having a corneal transplant at any future time if this is required, but INTACS may ultimately be found to delay or perhaps prevent the need for a corneal transplant, by helping to keep the cornea nearer to its natural shape.
INTACS inserts are an important additional option for keratoconus patients who are intolerant of contact lenses and whose only other option may previously have been a corneal transplant.
How do INTACS work?
Imagine your cornea as a tent with a curved top. If you push out the sides of the tent, the top flattens. Similarly, when INTACS inserts are placed in the sides of the cornea, they flatten the central cornea and so re-shape the cornea towards a more natural curvature.
INTACS inserts change the curvature of your eye by adding ultra-thin ring segments. They can be completely removed if necessary, returning your eyes to their preoperative condition.
Adding volume in the periphery of the cornea causes a flattening effect to reduce the curve of the cornea more centrally. This reduces the degree of myopia and astigmatism, so improving the level of vision that can be achieved without glasses or contact lenses. Furthermore, by reducing the corneal curvature, INTACS increase the likelihood of being able to fit and tolerate contact lenses. It may even be possible to use soft contact lenses to achieve the best visual result.
What happens after the operation?
There may be a single small stitch in the cornea. If so, this will be removed after a few weeks.
You will be given drops to use after the procedure. These will be:
- Antibiotic / anti-inflammatory drops for 4 weeks
- Lubricating artificial tear drops to use as required
Follow-up examinations will be arranged and you will be monitored carefully after your procedure.
These animations explain more about ICRS (Intacs)
When can I get new glasses / contact lenses?
The shape of the cornea will typically take 3 months (or longer) to stabilise and during this time your vision will fluctuate. Only once the cornea has become stable should you consider glasses or contact lenses for definitive correction of any residual refractive error.
Some people choose to seek temporary glasses or contact lenses during the recovery period. There is no objection to this, but the prescription may change until the cornea becomes stable.
How soon after my Intacs procedure can I have Crosslinking?
If your keratoconus requires a combination treatment of INTACS followed by corneal collagen crosslinking (CXL), we will usually wait for 1 – 3 months after the INTACS before we proceed to perform CXL.
At the Forefront of new Technology with INTACS SK
INTACS SK corneal inserts are used to treat severe keratoconus, achieving a greater effect than regular INTACS in these advanced cases.
The main difference is that the SK version is placed slightly closer to the centre of the cornea, with a diameter of 6mm. This gives a greater flattening effect on the cornea.
Mr Mohammed Muhtaseb performed 2 of the first 3 operations implanting INTACS SK in the UK, and was the first surgeon to implant regular INTACS in one eye and INTACS SK in the other eye of the same patient. He has published the results of a large series of INTACS SK procedures in the Journal of Cataract and Refractive Surgery:
J Cataract Refract Surg. 2012 Jan;38(1):129-36. Epub 2011 Nov 4.
International Intacs User’s Group Meeting
In April 2009 I was one of two international experts in the use of INTACS that were invited to speak about personal experience in the use of INTACS. We also discussed approaches to challenging cases and answered questions from delegates. The meeting was held at the Cabinet War Rooms in Central London. Also pictured are (left to right): Arnold Flores of Addition Technology, Prof Joseph Colin from France, and Ian Ponsford of Kestrel Ophthalmics.
As with any surgical procedure, there are risks of which you must be aware. Your doctor will explain these risks to you and ensure that you understand them completely. You will be given time to discuss all issues to your satisfaction.