Intacs / Ferrara Rings
As part of our wide range of treatments for Keratoconus, Intraocular Rings (Ferrara/Intacs) can offer relief for Keratoconus sufferers as well as patients with mild myopia (up to -4.00D).
They are particularly well suited to those who have been turned down for Laser vision correction because of thin corneas and also those worried about the irreversibility of laser surgery. The implants can be removed or exchanged if necessary.
Intraocular Rings (Ferrara/Intacs) are clear and thin prescription inserts placed in the periphery of the cornea by an eye surgeon and performed as an outpatient procedure.
Intraocular Rings (Ferrara/Intacs) reshape the curvature of the cornea from within, enhancing the natural shape of your eye to correct mild near-sightedness and astigmatism.
In those with Keratoconus the rings are used to normalise corneal shape as much as possible in order to improve vision with glasses or spectacles.
How do Intraocular Rings (Ferrara/Intacs) work?
Intraocular Rings (Ferrara/Intacs) alters and flattens the natural shape of the cornea to allow light rays to focus closer to or on the retina, thus improving vision.
To understand how Intraocular Rings produce good vision, imagine a tent with a domed top, a shape similar to that of your cornea. If the sides of the tent are extended outward, the top flattens slightly.
Intraocular Rings (Ferrara/Intacs) inserts work in a similar fashion.
When Intraocular Rings inserts are placed in the periphery (sides) of the cornea, outside the vital central optical zone, they gently reshape the centre or “top” of the cornea.
Before the Procedure
You will need to have a thorough preoperative eye examination to determine if your eyes are healthy and suitable for this procedure.
Your examination will include a variety of standard ophthalmic tests, general medical tests and a review of your medical history.
You will be have the opportunity to discuss the process with the staff and surgeons at Centre for Sight.
The procedure will be performed on another day (at least 24 hours after your initial consultation). The procedure itself will take less than 15 minutes per eye, but plan on at least a few hours for your visit.
The procedure for Intraocular Rings (Ferrara/Intacs)
Anaesthetic drops are used to numb the eye, which is held open throughout the procedure to prevent blinking.
Step 1: The Intralase Femtosecond laser (used for creation of the flap in Lasik at Centre for Sight) is used to create a 1mm incision and separate channels within the substance of the cornea.
Step 2: Intraocular Rings (Ferrara/Intacs) are then inserted into the channels one at a time. The eye is stabilised and rings rotated into place.
The cornea consists of several layers, much like a pad of paper. Creating space for the Intraocular Rings by the laser is like separating two pages just enough to create a space.
INTACS gently reshape the curvature of your cornea so that light rays focus properly on the retina. Objects in the distance, which once appeared blurry, become sharp and clear.
After the INTACS Procedure
You may have the sensation of grittiness in your eyes for a few hours and perhaps a slight irritation for a day or two. For Keratoconus, visual improvement takes longer and can take up to several months and may still need contact lenses or glasses in order to see well.
You will be on eye drops for a few weeks following the procedure and will need a follow up visit at the Centre for Sight soon after the procedure, 1 month and 6 months.
More about Intacs for Keratoconus?
At Centre for Sight INTACS are used mainly for the treatment of Keratoconus. Many patients come to see us for Lasik eye laser surgery, however are found not to be suitable because they have keratoconus which is sometimes subtle. Lasik is not suitable for patients with this condition, however Intacs or Ferrara ring inserts may be an option depending on the severity of the keratoconus. Your eye surgeon will after several investigations indicate whether your eye is suitable.
The Goals of Intacs or Ferrara rings is also different in that although we would like to fully correct the eye, this is not always possible. The goals are to improve the ability of the patient to tolerate glasses and contact lenses and obtain better vision. Many patients have become intolerant to lenses and traditionally the only option has been a corneal transplant. This procedure certainly has the potential to delay transplant surgery. Whether the procedure avoids transplantation altogether has yet to be determined.
Visual recovery in Keratoconus is also longer and can vary considerably from eye to eye. Tremendous fluctuation takes place early and then the vision gradually stabilises with many patients obtaining excellent vision with glasses or contact lenses. We emphasise: This is not like Lasik or laser eye surgery where visual recovery is rapid!
The use of Intralase at Centre for Sight has enabled us to enhance the procedure further and with changes in ring diameter we have been able to accomplish a large effect. Our nomogram is now being used by many other Intralase users around the world!
Authored by Sheraz Daya MD FACP FACS FRCS(Ed) FRCOphth, Consultant Ophthalmic Surgeon & Medical Director, June 2019.
Next review due June 2020.