Abstract
Purpose :
Use of preloaded intraocular lens (IOL) delivery systems in cataract surgery offers safer, shorter and non-touch IOL insertion compared to manually loaded systems. Preloaded IOLs can be implanted through small corneal incisions, which can reduce surgically induced astigmatism. We hypothesize that using a preloaded IOL system can reduce post-operative astigmatism to achieve better post-operative refractive outcomes.
Methods :
Data were collected retrospectively for 517 consecutive patients undergoing cataract surgery at Kent & Canterbury Hospital. A manually loaded Rayner C-Flex lens was used for 254 and a preloaded Zeiss CT-Lucia lens system for 263. To reduce confounding factors all procedures were performed by the same surgeon and complex surgical cases were excluded.
Data collected included pre and post-operative spherical equivalent refraction, target refraction and visual acuity (VA). Data were analysed by SPSS using chi-square, correlation and linear regression to determine:
1) Proportion of patients achieving post-operative refraction within 1D of their target
2) Correlation of post-operative spherical equivalence refraction and target refraction
3) Proportion of patients whose VA improved to 6/12 or better.
Results :
82.7% of the Rayner C-Flex group achieved post-operative refraction within 1D of their target compared to 99.6% with Zeiss CT-Lucia.
Post-operative refraction was positively correlated with target refraction for both systems; r = 0.344, p <0.01 for Rayner C-Flex and r = 0.327, p <0.01 for Zeiss CT-Lucia. In regression analysis significance only remained for the preloaded system: R2 = 0.347, p <0.01. Target refraction accounted for 35% of the variability of post-operative refraction with Zeiss CT-Lucia.
Proportion of patients with VA of 6/12 or better improved from 62.2% pre-operatively to 71.9% post-operatively with Rayner C-Flex compared to 71.6% to 89.4% with Zeiss CT-Lucia.
Conclusions :
Results support the hypothesis. Post-operative refraction was within 1D of target and post-operative VA improved for a higher proportion in the preloaded group. Furthermore, regression analysis implies target refraction can help predict post-operative refraction when using the preloaded system only. Future randomized control trials could help evaluate the hypothesis further, comparing various IOL delivery systems and better predict post-operative refraction.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.