To evaluate the short-term clinical outcomes obtained with a new model of asymmetric intracorneal ring segments (ICRS) with variable thickness and base width in keratoconus.
Four Spanish ophthalmologic centers DESIGN:: Prospective multicentre longitudinal non-comparative clinical trial METHODS:: Thirty-one keratoconus eyes of 25 patients (age, 15-50 years) that underwent implantation of ICRS of variable thickness and base (AJL-pro, AJL Ophthalmic, Vitoria-Gasteiz, Spain) in 4 Spanish centres were enrolled. Visual, refractive, topographic, aberrometric, and pachymetric changes were evaluated during a 3-month follow-up. Complications were also recorded.
Statistically significant changes after surgery were observed in uncorrected distance visual acuity (UDVA) (p=0.002) and corrected distance visual acuity (CDVA) (p=0.005), as well as in spherical equivalent (p=0.006). At 3 months postoperatively, no loss of 2 or more lines of CDVA was observed, while 48.4% (15) of eyes gained ≥ 1 line. Statistically significant changes were observed in the steepest and mean keratometric values (p≤0.047) as well as in the magnitude of astigmatism (p<0.001) of both anterior and posterior corneal surfaces. Likewise, a change to a less prolate shape of the anterior surface was found (p=0.011). Primary coma was also reduced significantly at 1 month postoperatively (p=0.001, mean reduction 40.1%). No serious implant-related complications occurred during the follow-up.
The implantation of intrastromal asymmetric ring segments of variable thickness and base width in keratoconus corneas induces a significant anterior corneal flattening, leading to refractive changes, a significant reduction of its prolate shape and irregularity, and improvement in patient’s corrected-distance visual acuity.