Decision making nomogram for intrastromal corneal ring segments in keratoconus

Area of Science:

• Ophthalmology
• Corneal Surgery
• Refractive Surgery

Background:

• Keratoconus is a progressive corneal ectasia leading to visual impairment.
• Intrastromal corneal ring segments (ICRS) are used to improve visual function in keratoconus.
• Standardized criteria for ICRS insertion can optimize surgical outcomes.

Purpose of the Study:

• To develop and validate a nomogram for guiding intrastromal corneal ring segments (ICRS) insertion in keratoconus patients.
• To assess the efficacy of the nomogram in improving visual and refractive outcomes.

Main Methods:

• A prospective, non-randomized, interventional case series was conducted at a tertiary eye care center.
• A self-designed nomogram based on cone centration, mean refractive spherical equivalent (MRSE), and mean keratometry (Km) was used for ICRS selection.
• Clinical outcomes at 3, 6, and 12 months were compared to historical controls.

Main Results:

• Eyes treated using the nomogram (Group A) showed significant improvements in uncorrected and best-corrected visual acuity (UDVA, CDVA), MRSE, Km, and astigmatism compared to historical controls (Group B).
• Group A achieved a statistically significant higher percentage of good clinical outcomes (P < 0.001).
• Specific improvements in Group A included UDVA from 0.16 to 0.25 and CDVA from 0.58 to 0.69.

Conclusions:

• The developed nomogram is an effective tool for selecting appropriate intrastromal corneal ring segments (ICRS) in keratoconus management.
• Utilizing this nomogram leads to significantly improved clinical outcomes for patients with keratoconus.
• The nomogram facilitates better patient selection and enhances the predictability of ICRS surgery outcomes.