A Comparison Of Predicted And Achieved Post-Operative Vaults In Implantable Collamer Lenses In Caucasian And Asian Eyes

To compare the clinically achieved vaults with the theoretical back calculation of predicted vaults in a Caucasian and Asian population using the predicted vault of the NK-formula V2 (NK-V2) and NK-formula V3 (NK-V3) in patients undergoing Implantable Collamer Lens (ICL) Surgery.

Single Tertiary Referral Centre

Data was collected retrospectively from three surgeons on all patients who had ICL surgery between September 2020 to August 2022 at Moorfields Eye Hospital. ICL sizing was with the optimal NK-V2. Post-operative vault was measured using anterior-segment OCT.

A total of 138 eyes from 73 patients were eligible. 73 eyes of 73 patients were included into our analysis (51 Caucasian patients). All measurements are in mm. Low, moderate and high vault in Caucasian v Asian eyes was 15.7% vs. 18.2%, 84.3% vs. 77.3% and 0% vs. 4.5% respectively. The NK-V2 mean and median absolute error for Asians was 0.31 and 0.33, respectively (range 0.01 to 0.81). Mean and median absolute error for Caucasians was 0.2 and 0.16, respectively (range 0.02 to 0.69), p-value = 0.029. The NK-V3 mean and median absolute error for Asians was 0.22 and 0.16, respectively (range 0.01 to 0.69). Mean and median absolute error for Caucasians was 0.16 and 0.15, respectively (range 0 to 0.5), p-value = 0.18.

NK-V2 formula is equally effective in Caucasian eyes compared to Asian eyes with no adverse outcomes or safety issues. NK-V2 formula showed statistical difference between Caucasian and Asian eyes. NK-V3 was superior in predicting postoperative vault compared to NK-V2 in both ethnic groups.