Refractive Outcomes And Accuracy Of Intraocular Lens Power Calculation Formulae In Nanophthalmic Eyes After Cataract Surgery
Published 2023 - 41st Congress of the ESCRS
Reference: PP22.12 | Type: Free paper | DOI: 10.82333/whgt-b503
Authors: Zixin Hong* 1 , Carl Eiselen 2 , Jack Kane 3 , Elaine Chong 4 , Christopher Girkin 5 , Alp Atik 6
1Department of Ophthalmology,Austin Health,Melbourne,Australia, 2Royal Melbourne Hospital,Melbourne,Australia, 3Department of Ophthalmology,Northern Health,Melbourne,Australia, 4Department of Ophthalmology,Royal Melbourne Hospital,Melbourne,Australia;Royal Victorian Eye and Ear Hospital,Melbourne,Australia;Centre of Eye Research Australia,Melbourne,Australia, 5Callahan Eye Hospital at the University of Alabama at Birmingham,Birmingham,United States, 6Department of Ophthalmology,Royal Melbourne Hospital,Melbourne,Australia;Royal Victorian Eye and Ear Hospital,Melbourne,Australia
Purpose
To report on refractive outcomes of cataract surgery and accuracy of multiple generations of intraocular lens (IOL) predictive formulae in nanophthalmic eyes.
Setting
Royal Victorian Eye and Ear Hospital in Melbourne, Victoria, Australia; and Callahan Eye Hospital at the University of Alabama at Birmingham, Birmingham, Alabama, United States.
Methods
A consecutive case series of nanophthalmic eyes with axial length (AL) <21mm undergoing uncomplicated cataract surgery with a single posterior chamber IOL were analysed. Main outcome measures were the mean prediction errors (ME) and the mean absolute errors (MAE) with SRK-T, Hoffer Q, Holladay 1, Haigis, Barrett, EVO and Kane power calculation formulae, as well as the proportion of eyes achieving absolute errors within 0.5 dioptres (D) of emmetropia and target refraction. ANOVA was used to compare the refractive accuracies of different predictive formulae.
Results
23 eyes of 23 participants were included in the current study (age range 26 to 76 years). Mean pre-operative spherical equivalent was +5.85D±2.16D. Mean post-operative spherical equivalent was -0.87D±1.04D. Mean AL was 20.09mm±0.60mm. There was a statistically significant difference in ME amongst the seven formulae (P=0.009) but not MAE (P=0.97). The ME was the lowest with Holladay 1 formula at 0.01±1.27D, followed by Kane at 0.12±1.21D, and Haigis at 0.18±1.22D (P=0.90). MAE was the lowest with Hoffer Q formula at 0.86±1.02D, followed by Kane at 0.91±0.78D, and Holladay 1 at 0.93±0.85D (P=0.97). 48% of eyes achieved refractive error within 0.5D of the refractive aim predicted by Hoffer Q formula, followed by 39% by Kane and EVO formulae.
Conclusions
Refractive outcomes with cataract surgery in nanophthalmos can be unpredictable. Our study demonstrated a significant difference in ME amongst the seven studied formulae, but there was no significant difference in MAE. The Hoffer Q, Kane and Holladay 1 formulae all demonstrated reasonable accuracy in nanophthalmic eyes.