Abstract
Purpose :
To develop and characterize a sensitive and translatable model of phacoemulsification in the New Zealand White Rabbit (NZW).
Methods :
A 2.8 mm clear corneal incision was made at the superior limbus, and a central curvilinear capsularexis (opening of the lens capsule) was performed. The lens cortex and nucleus were removed by phacoemulsification and aspiration with balanced salt solution (BSS). Hyaluronic acid (1.8%) was used as a viscoelastic during the surgical procedure to keep the eye inflated and was removed prior to corneal closure. Immediately prior to corneal closure, BSS was infused to reinflate the anterior chamber. Dexamethasone (DEX) or BSS was administered topically 4 times a day for 7 days after the surgical procedure. Hackett-McDonald (HM) ocular inflammatory scores, tonometry, pachymetry, and confocal microscopy (HRT-3, Heidelberg) to evaluate corneal endothelial cells (CECs) were performed on days 1, 3, and 7. All surgical eyes were collected for histopathology at the conclusion of the study.
Results :
Cumulative HM scores and central corneal thickness measurements were significantly lower (p<0.05) in eyes treated with DEX compared to BSS on day 3, and remained lower throughout the course of the study. Baseline intraocular pressures (IOP) were 18 mmHg, and in DEX treated eyes increased above 30 mmHg on day 1. By day 7, IOPs in both groups were similar, but below baseline (10 mm Hg). On CEC assessments, the endothelium was not significantly different between the treatment groups.
Conclusions :
Using this phacoemulsification model, we demonstrated that topical DEX inhibited ocular inflammation and reduced corneal thickness compared to BSS. This phacoemulsification model allows quantitative assessment of specific anti-inflammatory therapies, and can be used in pre-clinical development to provide effective proof of concept of novel compounds or delivery methods.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.