Posters

Inter-operator variability in visual and refractive outcomes of 3 surgeons performing laser-assisted in situ keratomileusis (LASIK) on patients with mild to moderate myopia

Poster Details

First Author: H.Ong UK

Co Author(s):    A. Ionides   D. Gartry   M. Wilkins        

Abstract Details

Purpose:

In the current literature, there is no evidence to suggest that different surgeons performing LASIK using the same excimer laser machine result in different visual or refractive outcomes. The aim of this study is to investigate inter-operator variability in visual and refractive outcomes of 3 experienced surgeons performing LASIK using the same excimer laser machines at a single centre to treat patients with mild to moderate myopia.

Setting:

Moorfields Eye Hospital, London, United Kingdom.

Methods:

Three experienced refractive surgeons performed LASIK on 2 excimer laser machines (Technolas 217 and VISX S4) at a single centre. Pre-operative and 3-month post-operative data of patients who had undergone laser refractive eye surgeries were routinely entered into a database. Data of patients who received LASIK treatment for correction of myopia performed by the 3 surgeons between January 2008 and November 2013 were extracted and analysed retrospectively. Inclusion criteria included pre-operative myopia of between -0.5D to -6.5D and astigmatism of ≤2.0D. Patients who had previous refractive or intraocular surgery, traumatic eye injury, and other ocular co-morbidities affecting visual potential were excluded. For each laser system, data of 50 patients from each of the 3 surgeons were selected at random using random number generation through a third party. An independent observer performing outcome analyses was masked to the identity of the surgeons. One-way analysis of variance (ANOVA) was applied to test the equality of variables between surgeons.

Results:

2731 patients met the inclusion criteria. The Technolas 217 was used to treat 1975 eyes of 1735 patients. The VISX S4 was used to treat 1722 eyes of 996 patients. Data of 300 patients were extracted and analysed. 157/300 (52.3%) were female patients. Median age was 38 years (interquartile range [IQR] 32-46). 153/300 (51.0%) were right eyes. Mean pre-operative spherical equivalent (SE) treated was -3.88±1.59 D. Pre-operative SE of patients were similar between the 3 surgeons (F[2,296]=0.293, p=0.747). At 3 months, mean post-operative unaided decimal visual acuity was 1.09±0.28 and mean post-operative SE -0.09±0.41D. For the Technolas 217 laser system, there were no significant differences in outcomes of patients operated by the 3 surgeons in post-operative unaided visual acuities (F[2,147]=1.634, p=0.199) and post-operative SE (F[2,147]=0.101, p=0.489). Similarly, for the VISX S4 laser system, there were no significant differences in outcomes of patients operated by the 3 surgeons in post-operative unaided visual acuities (F[2,147]=1.958, p=0.145) and post-operative SE (F[2,147]=2.309, p=0.103).

Conclusions:

This study shows that there is little inter-surgeon variability in visual and refractive outcomes when patients with mild to moderate myopia undergo LASIK on the same excimer laser machine. FINANCIAL INTEREST: NONE