Ferrara Rings for Visual Rehabilitation in Eyes with Keratoconus and Previous Cross-Linking Using the Ferrara Ring...

Area of Science:

• Ophthalmology
• Corneal Surgery

Background:

• Keratoconus is a progressive thinning of the cornea, leading to irregular astigmatism and visual impairment.
• Corneal cross-linking (CXL) is a treatment to halt keratoconus progression.
• Intrastromal corneal ring segments (ICRS) are used to regularize the corneal surface and improve vision in keratoconus.

Purpose of the Study:

• To evaluate the visual, refractive, and tomographic outcomes of intrastromal corneal ring segments (ICRS) implantation in eyes with a history of keratoconus and prior corneal cross-linking.
• To assess the efficacy of the Ferrara ring nomogram in guiding ICRS implantation for this patient group.

Main Methods:

• A retrospective, interventional case series was conducted.
• Ferrara Intrastromal Corneal Ring Segments were implanted in 21 eyes of 19 patients with prior CXL for keratoconus.
• Ring segment selection followed the Ferrara ring company nomogram.

Main Results:

• Mean uncorrected visual acuity improved from 0.88 to 0.52 logMAR (p < 0.001).
• Mean corrected visual acuity improved from 0.47 to 0.36 logMAR (p = 0.046).
• Significant improvements were observed in spherical equivalent, refractive astigmatism, and corneal tomography (mean keratometry and keratometric astigmatism).

Conclusions:

• Implantation of Ferrara rings in keratoconic eyes with a history of prior cross-linking, using the company nomogram, leads to significant improvements.
• The procedure positively impacts visual acuity, refractive error, and corneal shape.
• ICRS implantation is an effective option for visual rehabilitation in eyes with advanced keratoconus post-CXL.