Saturday, September 13, 2008

INTACS show excellent long-term results for keratoconus


Patients with keratoconus may derive long-term benefit from the implantation of intracorneal ring segments (INTACS, Addition Technology) in order to stabilise the progression of the disease and improve their visual outcomes, according to Joseph Colin MD.

Addressing delegates at the XXVI Congress of the ESCRS during a special clinical research symposium on keratoconus, Dr Colin said that the results of eight-year follow-up with INTACS suggests that they provide surgeons with a viable therapeutic alternative for ectatic diseases affecting the cornea.

“Our study demonstrated that INTACS segments are a safe and efficacious option for the treatment of patients with moderate to severe keratoconus who are contact lens intolerant. The improved functional vision associated with this treatment modality can defer or potentially eliminate the need for corneal transplantation,” he said.

Dr Colin, Hopital Pellegrin, Bordeaux, France, said that the broad goals of intracorneal rings in keratoconus are to stabilise the corneal topography, improve uncorrected- and best-corrected visual acuity, improve contact lens tolerance and spectacle use and delay the need for penetrating or deep lamellar keratoplasty.

Discussing the properties of the INTACS segments, Dr Colin noted that the clear micro-thin PMMA inserts are hexagonal in cross-section, with an arc length of 150°. The new model of the segments allows for an optical zone of 6.0mm compared to 7.0mm previously.

Reviewing the results of patients treated at CHU Bordeaux, Dr Colin said that the outcomes have been positive in 60 out of 65 eyes and have remained stable up to eight years after implantation. He also noted that penetrating keratoplasty could be carried out if necessary, as was the case for five patients in this study.

Dr Colin said that one of the clear advantages of INTACS implantation is that it is a fully reversible procedure.

“Removing INTACS is relatively straightforward once you follow the same steps as for the initial procedure. Using a diamond knife, you cut to two-thirds depth, reopen the incision and use Sinskey hooks to pull out the segments. You can then proceed with penetrating or lamellar keratoplasty in the same procedure,” he said.

Looking to the future, Dr Colin said that developments such as femtosecond-assisted creation of the channels for Intacs implantation, and synergistic approaches using ultraviolet collagen crosslinking to strengthen the cornea also hold considerable promise for the diagnosis and treatment of keratoconus.

No comments: