Impact Of Programmable Refractive Correction On The Predictive Accuracy And Overestimation Profile Of The Katsim Vision Simulator In Cataract Surgery
Published 2026 - 44th Congress of the ESCRS
Reference: FP29.02 | Type: Free paper | DOI: 10.82333/54j9-g750
Authors: Dr Rustu Emre Akcan* 1 , A/Prof. Ayse Yildiz 1 , A/Prof. Cem Kesim 1 , Ehsan Varasteh 2 , Arda Gulersoy 2 , Koray Kavakli 2 , Parviz Zolfaghari 2 , Huseyin Guzel 3 , Martina Sofronijevikj 4 , Prof. Dr Murat Hasanreisoglu 1 , A/Prof. Semra Tiryaki Demir 3 , A/Prof. Biljana Kostovska 5 , Prof. Dr Christina Nikolova Grupcheva 6 , Prof. Hakan Urey 2 , Prof. Dr Afsun Sahin 1
1Ophthalmology,Koc University Hospital,Istanbul,Türkiye, 2Electrical and Electronics Engineering,Koc University,Istanbul,Türkiye, 3Ophthalmology,Sisli Hamidiye Etfal Research and Training Hospital,Istanbul,Türkiye, 4Ophthalmology ,Sistina Eye Hospital,Skopje,North Macedonia, 5Ophthalmology,Sistina Eye Hospital,Skopje,North Macedonia, 6Ophthalmology,Medical University of Varna,Varna,Bulgaria
Purpose
Cataract surgery outcomes rely on accurate preoperative assessment; however, predicting postoperative visual acuity remains challenging, as conventional methods lack precision in estimating true visual potential. The KATSIM project has developed a novel vision simulator using varifocal lens technology to project stimuli through relatively clear lens regions to estimate postoperative best-corrected visual acuity (BCVA). The addition of programmable refractive correction may further enhance predictive performance. This study aimed to evaluate whether refractive correction improves predictive accuracy while assessing its potential impact on visual acuity overestimation compared with standard KATSIM assessment and conventional pinhole testing.
Setting
This single-blind observational study was conducted at the Ophthalmology Departments of Koç University Hospital (Istanbul, Turkey), Sistina Eye Hospital (Skopje, North Macedonia), Şişli Hamidiye Etfal Research and Training Hospital (Istanbul, Turkey), and Grupcheva Vision Center (Varna, Bulgaria) as part of the KATSIM project.
Methods
A total of 210 eyes from 145 cataract patients scheduled for surgery were evaluated. Preoperatively, postoperative BCVA was predicted using the KATSIM vision simulator (with and without programmable refractive correction) and conventional pinhole testing. The simulator employs varifocal lens technology to project stimuli through clearer lens regions. Postoperative BCVA at 1 month served as reference. Visual acuity was measured using Snellen charts and converted to logMAR. Predictive accuracy was assessed using mean absolute error (MAE). Linear mixed-effects models with patient-level clustering and Bonferroni-adjusted pairwise comparisons were performed using STATA 17.0.
Results
A total of 210 eyes from 145 patients (53 male, 92 female; 39–88 years) were analyzed. Mean preoperative visual acuity was 0.68 ± 0.27 logMAR, improving to 0.07 ± 0.09 logMAR at 1 month postoperatively. Pinhole predicted 0.43 ± 0.20 logMAR, whereas KATSIM predicted 0.22 ± 0.13 logMAR, improving to 0.19 ± 0.13 logMAR with programmable refractive correction. Overestimation occurred in 5 eyes (2.4%) with KATSIM and 6 eyes (2.8%) with programmable refractive correction (p=0.312), but none with pinhole; 2 of them were associated with Irvine Gass Syndrome. Prediction error was higher with pinhole (MAE: 0.36 ± 0.19 logMAR) than KATSIM (MAE: 0.16 ± 0.11 logMAR; p<0.001). Refractive correction further reduced MAE to 0.14 ± 0.10 logMAR (p=0.049).
Conclusions
The KATSIM vision simulator demonstrated significantly greater predictive accuracy than conventional pinhole testing for estimating postoperative BCVA in cataract patients. The addition of programmable refractive correction further improved precision with similar overestimation rate. These findings suggest that incorporating refractive correction may enhance the simulator’s ability to predict postoperative visual acuity without increasing the risk of overestimation.