Size and configuration of implantation pocket do not affect the outcome of the Raindrop(ReVision Optics, Inc) presbyopic inlay

Session Details

Session Title: Refractive
Session Date/Time: Sunday 28/02/2016 | 08:30-11:00
Paper Time: 08:48
Venue: Skalkotas
First Author: : A.Konstantopoulos UK
Co Author(s): :    Y. Liu   C. Nyein   E. Teo   G. Yam   J. Mehta  

Abstract Details

Purpose:

Corneal inlays are an increasingly popular option for the surgical compensation of presbyopia. The ability to create corneal pockets with femtosecond laser, combined with its safety and precision, may facilitate further adoption. The vast majority of inlays to date, however, have been implanted under a corneal flap. Pocket advantages including a smaller size, less dry eye and less neurotrophic effect. Primary aim of this study was to investigate the effect of different pocket dimensions and configurations on the refractive outcome and corneal stability after Raindrop implantation in a rabbit model. Secondary aim was to investigate the associated wound healing response.

Setting:

Singapore National Eye Centre and Singapore Eye Research Institute.

Methods:

Ten New Zealand White rabbits had bilateral Raindrop implantation. The 20 eyes were allocated equally to 4 surgical groups: pockets with 4mm, 6mm, and 8mm diameter (Ziemer FEMTO LDV Z6), and a flocket (a hybrid of pocket and flap) with 8mm diameter (VisuMax, Carl Zeiss Meditec). The rabbits were examined before surgery, at day 1, and weeks 1, 2, 3 and 4 following surgery. Slit lamp photography, anterior segment optical coherence tomography, anterior surface topography and in-vivo confocal microscopy were performed. After euthanasia at week 4, excised corneas were examined with immunofluorescence for CD11b, heat shock protein(HSP) 47 and fibronectin.

Results:

Corneal thickness (mean±SD) increased from 360.0±16.2μm before implantation to 383.9±32.5, 409.4±79.3, 393.6±35.2, 396.4±50.7 and 405±20.3μm on day 1 and weeks 1,2,3 and 4 respectively (p=0.005). Corneal refractive power increased, from 50.3±3.8D preoperatively, by 11.1±5.5, 7.5±2.5, 7.5±3.1, 7.0±3.6 and 6.3±2.9D respectively (p<0.001). Corneal astigmatism increased from 1.1±0.3D to 2.3±1.6, 1.7±0.7, 1.8±1.0, 1.6±0.9 and 1.6±0.9D respectively (p=0.033). There was no significant difference in CT, refractive power change and astigmatism between the 4 surgical groups. The 4mm group had the highest stromal keratocyte reflectivity throughout the study; the 8mm pocket and flocket groups the least. CD11b, fibronectin or HSP47 were not detected.

Conclusions:

The cornea achieved anatomical and refractive stability by 1 week following Raindrop implantation in both pocket and flocket groups; the increase in corneal thickness and refractive power did not change significantly after week 1. This is consistent with human data for Raindrop implantation under a flap. Implantation in a pocket or flocket did not affect outcomes, nor did pocket size, although the 8mm groups showed less keratocyte activation. The post-implantation wound healing did not show evidence of an inflammatory or scarring response after 4 weeks. In summary, a pocket or flocket may be equally effective and safe for Raindrop implantation.

Financial Disclosure:

NONE