Long-Term Follow-up of Intrastromal Corneal Ring Segment Implantation in Pediatric Keratoconus

Abstract

Purpose: To evaluate efficacy, safety, and stability of Ferrara-type intrastromal corneal ring segment (ICRS) implantation for visual rehabilitation in pediatric patients with keratoconus. Methods: This study included patients with keratoconus aged 18 years or younger who had received Ferrara-type ICRS implantation. The uncorrected and corrected distance visual acuities, residual refractive errors, and root mean square for coma-like aberration were recorded preoperatively and at 6 months, 1, 3, and 5 years postoperatively. Results: One hundred eighteen eyes of 88 patients (mean age 16.1 6 1.89; range 10-18) were studied. All patients were examined at a 6-month follow-up after ICRS implantation, and at the 12-, 36-, and 60-month follow-ups, 97, 71, and 23 eyes were evaluated, respectively. Mean uncorrected distance visual acuity (logarithm of minimum angle of resolution) changed from 0.67 6 0.37 preoperatively to 0.37 6 0.30, 6 months after ICRS implantation (P , 0.0001). Mean corrected distance visual acuity increased in turn from 0.19 6 0.15 to 0.10 6 0.12 (P , 0.0001). The percentage of eyes with a refractive cylinder #2.00 D increased from 30.5% before surgery to 70.3% 6 months later, and the root mean square for corneal coma-like aberration showed a statistically significant decrease (P , 0.001). At the follow-up visits, refractive and visual values remained stable compared with those of the 6-month visit. Conclusions: Our long-term results suggest that Ferrara-type ICRS implantation is a safe, effective, and stable procedure for restoring vision in pediatric patients with keratoconus.

Intracorneal Ring Segment Implantation for the Management of Keratoconus in Children

“…Recently, Sedaghat and colleagues [27] confirmed in adult patients implanted with the same type of ICRS (KeraRing) that a greater difference between the preoperative uncorrected and corrected distance visual acuity and more coincidence of the most elevated points in the two corneal surfaces on the elevation maps increased the rate of successful outcome. Despite the non-statistically significant change in refraction, significant modifications were found in the current series in keratometric readings, the magnitude of corneal astigmatism, and logMAR CDVA, as in previous series using the same and other type of ICRS in adults and children [12][13][14]. Specifically, significant central corneal flattening, reduction of magnitude of astigmatism and improvement of CDVA were observed, with 52.8% of eyes showing a reduction in the magnitude of anterior corneal astigmatism of 1 D or more.…”

“…Several studies have confirmed the validity of CXL [11] and contact lenses fitting of special designs, such as scleral lenses [17], for the management of keratoconus, even in children [18][19][20][21]. Likewise, some studies have shown the potential of the use of ICRS in keratoconus in children, allowing a regularization of the corneal surface, an improvement of visual quality and even an improvement in contact lens tolerance [13,14,22,23]. In most of the cases, this implantation was combined with CXL [22,23].…”

“…Heikal et al [28] found in a sample of 20 adult keratoconus eyes implanted with KeraRing using the femtosecond laser technology that mean LogMAR CDVA improved from 0.85 ± 0.17 preoperatively to 0.26 ± 0.11 at 3 months postoperatively (p = 0.001). Alfonso et al [13] reported in a sample of 118 eyes of 88 children a change of mean CDVA from 0.67 ± 0.37 logMAR preoperatively to a value of 0.37 ± 0.30 logMAR at 6 months after ICRS implantation. In the current series, a change from a mean preoperative value of 0.86 ± 0.67 logMAR to a mean 3-month postoperative value of 0.30 ± 0.32 logMAR was observed.…”

“…A similar situation was reported by Haddad et al [32] when comparing the outcomes of two different types of ICRS, being one of them KeraRing. It should be considered that corneal high order aberrations increase with the level of severity [13], and the efficacy of ring segments is conditioned by this aberrometric profile [31]. Possibly, significant changes in primary coma RMS would have been detected if a larger sample would have been evaluated and subdivided by severity groups.…”

“…Despite the proved efficacy and safety of intracorneal ring segments (ICRS) for the management of keratoconus [12], there are few studies evaluating the potential usefulness of this treatment option in children [13,14]. The aim of the current study was to evaluate the safety and efficacy of ICRS implantation in keratoconus in children, evaluating changes in visual acuity, refraction, pachymetry, corneal topography and aberrometry, and corneal endothelial density during a 3-month follow-up.…”