Comparison Of Hill – Rbf 3.0, Barrett Universal Ii, Haigis And 3Rd Generation Iol Power Formulae To Predict The Accuracy Of Post-Cataract Surgery Refractive Outcomes In Indian Eyes
Published 2023 - 41st Congress of the ESCRS
Reference: PO0412 | Type: Free paper | DOI: 10.82333/rcfd-eq33
Authors: Tanie Natung* 1 , Ishita Pandey 1 , Benjamin Nongrum 1
1Ophthalmology ,North Eastern Indira Gandhi Regional Institute of Health & Medical Sciences (NEIGRIHMS),Shillong,India
Purpose
To compare the accuracy of refractive error predictions determined using Hill–RBF 3.0, Barrett Universal II (BU II), Haigis and 3rd generation Intraocular lens power formulae and to find the correlation between the absolute errors given by different formulae for different axial lengths in Indian eyes.
Setting
A tertiary-care institute in North-East India
Methods
Patients with cataract who underwent uneventful phacoemulsification with PC IOL implantation and operated by highly experienced phaco surgeons were included in this study. The IOL Master 500 biometer was used to measure the axial length, keratometry and ACD before and 1 month after the IOL implantation. Final post-operative refractions were expressed as spherical equivalents. Mean Arithmetic errors, Mean Absolute errors (MAEs) and Median Absolute errors (MedAEs) were calculated for post-operative refractions predicted by different IOL power formulae and were compared. The percentage of eyes that had predicted target refractive errors within ±0.25 D, ±0.5 D, ±0.75 D, ±1.0 D, >±1.0 D were also measured.
Results
A total of 219 eyes of 173 patients were included. The patients were divided into three groups: Group A (AL<22 mm, n=19), Group B (AL=22-24.5 mm, n=185) and Group C (AL>24.5 mm, n=15). For the entire population, BU II gave the lowest MAE (0.27635±0.27637) and the lowest MedAE (0.205 D) followed by Hill RBF 3.0 with MAE (0.2837±0.27841) and MedAE (0.215). For the short and long ALs, IOL power formulae with lowest MAE were Hill-RBF 3.0 (0.32684±0.326829 D) and SRK/T (0.28233±0.264162 D) respectively. The BU II had the largest percentage of eyes within ±0.25D, ±0.75D and ±1.00D of target refraction, being 57.5%, 95.4% and 98.6% respectively. However, Hill-RBF 3.0 had the largest percentage of eyes (88.1%) within ±0.50 D of target refraction.
Conclusions
Barrett Universal II was found to be the most accurate IOL power calculating formula in predicting the post-operative target refraction amongst all the IOL formulae followed by Hill RBF 3.0 in Indian eyes. Hill RBF 3.0 was found to be the most accurate IOL power formula for short axial lengths (AL < 22 mm). SRK/T was found to be the most accurate IOL power formula for long axial lengths (AL > 24.5 mm).