Intracorneal Ring Segments Implantation Outcomes Using Two Different Manufacturers' Nomograms for Keratoconus Surgery

Area of Science:

• Ophthalmology
• Corneal Surgery
• Refractive Surgery

Background:

• Keratoconus is a progressive corneal ectasia leading to irregular astigmatism and vision loss.
• Intracorneal ring segments (ICRS) implantation is a surgical option to regularize the cornea and improve visual acuity.
• Different ICRS manufacturers offer nomograms for surgical planning, potentially influencing outcomes.

Purpose of the Study:

• To compare the efficacy of two different ICRS manufacturers' nomograms in treating keratoconus.
• To evaluate visual, refractive, keratometric, and aberrometric outcomes after ICRS implantation.
• To analyze astigmatic changes using advanced vector analysis methods.

Main Methods:

• ICRS implantation using Keraring (Mediphacos) and Ferrara Ring (AJL Ophthalmics) nomograms in eyes with similar keratoconus patterns.
• 6-month follow-up assessing visual acuity, refraction, keratometry, corneal aberrometry, and optical quality.
• Vectorial analysis of astigmatic changes, including double-angle polar plots and the Alpins method.

Main Results:

• Both ICRS nomograms significantly improved visual and keratometric parameters (P < .05).
• Corneal aberrometry and optical quality showed significant improvements, except for trefoil.
• The Keraring group exhibited a statistically significant greater correction of tomographic astigmatism (P = .03).

Conclusions:

• Both ICRS nomograms provide significant improvements for keratoconus patients.
• The Keraring nomogram appears more effective in correcting corneal tomographic astigmatism.
• Nomogram choice may influence the degree of astigmatism correction in ICRS surgery.