Abstract
Purpose :
To investigate the effect of latanoprost, an ocular hypotensive prostaglandin analog, on choroidal thickness and structure in young healthy guinea pigs.
Methods :
Young (three-month-old) guinea pigs (n=3) underwent daily monocular treatment with 0.005% latanoprost for 2-weeks. Tonometry (iCare) and retinoscopy were undertaken to monitor IOP and refractive error (recorded as spherical equivalent values), respectively. Choroidal thickness (ChT) was measured using high frequency A-scan ultrasonography and posterior segment SD-OCT (Bioptigen), which also allowed Ch blood vessel (BV) area to be analyzed. Image J was used to analyze SD-OCT images.
Results :
As expected, latanoprost significantly reduced IOP in treated eyes. Mean interocular IOP differences (± SE) changed from -0.44±0.48 mmHg at baseline to -2.89±1.13 mmHg at 2 weeks (p= 0.05). Latanoprost also induced significant choroidal thickening: mean interocular ChT differences, as measured by SD-OCT, changed from 72.44±6.23 to 80.22±10.08 µm (p<0.0001), with the BV area in the choroids of treated eye also increasing significantly, from 671.89±199.85 to 692.44±159.35 (p=0.0002). Refractive errors were unaffected; interocular differences changed from -0.71±0.80 to 0.25±0.63 D (p= 0.19).
Conclusions :
Daily topical latanoprost administered to otherwise untreated young healthy guinea pigs resulted in choroidal thickening, with vascular changes at least partly accounting for this increase. The possibility that such choroidal changes underlie the inhibitory effect of latanoprost on myopia progression in young guinea pigs (El-Nimri et al, ARVO 2017) awaits further investigation.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.