Abstract
Purpose :
To evaluate the safety of SynergEyes hybrid contact lens under closed-eye conditions. Comparative study between SynergEyes hybrid contact lens ( petrafocon A DK 130 center/ hem-larafilcon A DK 84 skirt) and Brighten Optix EZ orthokeratology lens (Hexafocon A DK 100) was conducted on rabbit eyes under closed-eye conditions for 22 days to determine significant histopathological differences.
Methods :
Six healthy male New Zealand White rabbits were used in the study. Right eye of each rabbit was fitted with SynergEyes hybrid contact lens (test lens). Left eye of each rabbit was fitted with Brighten Optix EZ orthokeratology (orthoK) lens (control lens). Each lens (control and test lenses) was placed on the rabbit’s eye for 7-8 hours for 21 days. Lenses were cleaned and disinfected according to lens manufacture instructions after daily lens removal. Both eyes were examined daily prior to lens insertion and recorded using the Draize scoring system. Eyes were examined with 1% fluorescein stain after lens removal on Day 8, 15, and 22 and recorded using McDonald-Shadduck scoring system. The refractive error, corneal curvature, intraocular pressure (IOP), horizontal visible iris diameter (HVID), corneal center thickness, and endothelium cell of rabbits were taken at Day 0 and Day 22. Corneal tissue was fixed and stained with hematoxylin and eosin Y for microscopic evaluation at the end of the study.
Results :
There was no significant difference between Day 0 and Day 22 of 100% of the rabbit for refractive error, IOP, HVID, corneal center thickness, and endothelium density. According to Draize scale for scoring ocular lesions of conjunctivae was Level 1. Based on McDonald Shadduck scoring system, trace of epithelial damage, mild of epithelial damage, and trace of conjunctival congestion were observed. Conjunctiva inflammatory cell infiltration and focal hyperplasia in stratified squamous corneal epithelium were observed in test and control eye of rabbits with minimal to mild severity.
Conclusions :
The study results showed no significant histopathological differences between OrthoK lens (control lens) and hybrid lens (test lens). Both lenses did not induce significant clinical signs or ocular gross changes for 100% of the rabbits during the closed eye conditions. This study proved both Brighten Optix EZ OrthoK lens and SynergEyes Hybrid lens are safe for overnight wear.
This is a 2020 ARVO Annual Meeting abstract.