ESCRS - PO024 - INTRAOCULAR LENS POWER CALCULATION CHANGES FOLLOWING KERANATURAL IMPLANTATION IN KERATOCONUS PATIENTS

INTRAOCULAR LENS POWER CALCULATION CHANGES FOLLOWING KERANATURAL IMPLANTATION IN KERATOCONUS PATIENTS

Published 2025 - 29th ESCRS Winter Meeting

Reference: PO024 | Type: Free Paper | DOI: 10.82333/z29w-3y88

Authors: Burcu Yucekul* 1 , Dilan Colak 2 , Ugur Tunc 3 , Songul Kilic 1 , Aylin Kilic 4

1Haseki Training and Research Hospital,Istanbul,Türkiye, 2Eyup State Hospital,Istanbul,Türkiye, 3Istanbul Medipol University,Istanbul,Türkiye, 4Swiss Vision Clinic,Istanbul,Türkiye

Purpose

This study aims to assess biometric and intraocular lens (IOL) power and toric calculation changes after Corneal Allogenic Intrastromal Ring Segment (CAIRS) implantation in keratoconus patients.

Setting

Tertiary care private practice

Methods

A total of 25 eyes of 25 keratoconus patients (75.9% male, 24.1% female; mean age: 32.9±12.9 years) underwent CAIRS implantation. Key parameters, including axial length (AL), anterior chamber depth (ACD), lens thickness (LT), central corneal thickness (CCT), white-to-white (WTW) distance, K1 and K2 keratometry, and IOL power predictions (Barrett Universal, Barrett Total K, and Kane formulas) were measured preoperatively and three months postoperatively. Intra-correlation coefficients (ICC) between IOL formulas were also evaluated to assess the stability and reliability of the measurements.

Results

Postoperatively, significant increases were found in CCT (from 442.75±40.73 µm to 486.42±64.78 µm, p=0.001) and LT (from 3.78±0.39 mm to 3.80±0.40 mm, p=0.042). K1 and K2 keratometric values decreased significantly (p<0.001), and IOL power predictions (Barrett Universal, Barrett Total K, and Kane) showed substantial increases (p<0.001). The preoperative ICC among the IOL formulas was high (0.985 [0.979–0.991]), which further improved postoperatively to 0.993 (0.986–0.997), indicating strong consistency. No statistically significant differences were noted in AL (p=0.317), ACD (p=0.590), or WTW (p=0.407). Astigmatism showed a decrease (pre-op 5.32±2.86 D, post-op 4.56±2.55 D, p=0.324) though it was not statistically significant.

Conclusion

CAIRS implantation in keratoconus patients results in significant changes in keratometric readings, astigmatismand IOL power predictions, enhancing biometric consistency. For keratoconus patients requiring cataract or refractive lens surgery, performing CAIRS prior to lens surgery allows for more accurate IOL power predictions. The improved consistency in formula correlation postoperatively supports this approach, particularly when toric IOLs are considered for better refractive outcomes.