Clinical Outcomes of Intrastromal Corneal Ring Segments Implantation with a New Nomogram Based on Cone Location and Q-Value in Keratoconus Patients

Background: Keratoconus (KC), a progressive corneal disorder, poses significant challenges to visual acuity and quality of life. Intrastromal Corneal Ring Segments (ICRS) implantation holds promise as a treatment option for KC.Objectives: This study aimed to assess the effectiveness of personalized Intrastromal Corneal Ring Segment (ICRS) implantation based on cone location and Q-value, utilizing a newly developed nomogram, in improving visual and refractive outcomes for keratoconus patients.Patients and methods: Fifty eyes of 50 keratoconus patients were enrolled in a prospective, randomized controlled clinical study. The study employed a newly developed nomogram to determine the choice of single or double ICRS implantation based on cone location and the Q-value of the cornea. Visual acuity, refractive status, keratometry, corneal thickness, topographic parameters, and corneal asphericity were assessed preoperatively and postoperatively over 12 months. Statistical analysis was performed to evaluate the significance of the results.Results: Using our new nomogram revealed significant improvements in various visual and refractive parameters after 3 months. Uncorrected Distant Visual Acuity (UDVA) and Corrected Distant Visual Acuity (CDVA) showed substantial enhancement, along with reductions in Refractive Sphere and Refractive Cylinder, all of which were statistically significant (P < 0.0001). These improvements were maintained over the subsequent 9 months, indicating the efficacy and durability of our new nomogram.Conclusion: Our study introduces an innovative and personalized approach to the management of keratoconus through the development and application of a new nomogram. By considering the individual characteristics of each patient's cornea, including cone location and Q-value, we were able to tailor the implantation method for optimal corneal reshaping and restoration. Our results demonstrated significant improvements in visual acuity, refractive measures, and corneal curvature, highlighting the effectiveness of our new nomogram.