Corneal lifting technique reshapes ectactic cornea in keratoconus

By Conni Bergmann Koury; Reviewed by Cesar C. Carriazo, MD

In keratoconic patients, there is a need for a refractive procedure that could achieve higher corrections without decreasing the optical zone, so as to avoid the induction of higher-order aberrations (HOAs).

“Corneal lifting may be a viable treatment to reshape the ectactic cornea by means of a laser-created crescent keratectomy,” said Cesar C. Carriazo, MD, founder and scientific director, Carriazo Centro Oftalmologico, Barranquilla Colombia, and refractive and anterior segment ophthalmologist, Instituto Barraquer de America, Bogota, Colombia.

He reviewed results showing the technique reduced anterior chamber depth (ACD), decreased keratometry, and correction of irregular astigmatism and HOAs, despite using large optical zones.

“For the surgical technique, topical anesthetic is instilled,” Dr. Carriazo said. “The laser goes through a plastic mask and removes tissue. Depending on the patient’s keratoconus group, a 180º, 270º, or 360º keratectomy is performed with a specific surgical nomogram.”

Once the ablation is completed, the edges of the resection are sutured with interrupted stitches.

Study results

The study included 69 cases, the average patient age was 30.83 ±12.65, with 51 men and 18 women. Patients had an average follow-up of 25.91 months ±6.77 (range, 3–36).

In all three groups, there was no statistically significant change in pachymetry or the endothelial cell count, however, the anterior chamber depth was reduced in all cases. Patients’ UCVA, sphere, cylinder, and BCVA improved in all cases (Figures 1 to 3).

HOAs decreased as well, especially coma, he said, noting UCVA results at 3 years were achieved with PRK.

“Even in the 360º group, the worse cases, anterior chamber depth was reduced by 150 μm,” he said. “All measures improved in terms of UCVA, sphere, cylinder, and BCVA; HOA and coma were reduced in all cases; and amazingly,  most of the patients gained up to 6 lines of vision with none losing vision.”

Keratometry in all cases revealed corneal flattening 3 years later.

More findings

The anterior chamber depth decreased as long as arc length keratectomy increased, Dr. Carriazo and his colleagues found. With corneal lifting, sphere values decreased in all cases.

“Cylinder was overcorrected in most cases to generate a hyperopic residual refraction,” he said. “Hyperopic refractions are better to preserve the thinnest point of the cornea when refractive surgery is performed in 1 or 2 years.”

The investigation found that coma decreased up to 55% with respect to preoperative values (statistically significant) and no loss of BCVA was seen in any case-rather there was at least 2 lines of vision gained in most cases, also a statistically significant difference.

Corneal lifting produced a reduction of optical aberrations and gain of visual acuity with statistically significant improvement at 3-year follow-up achieved after PRK,” concluded Dr. Carriazo.

Cesar C. Carriazo, MD

e: ccarriazo@carriazo.com

This article was adapted from Dr. Carriazo’s presentation at the 2017 meeting of the American Academy of Ophthalmologyg. He receives royalty fees from Schwind.