The effect of race and selective laser trabeculoplasty on the aqueous humor dynamics in patients with glaucoma /

Resumo

This PhD titled “The effect of race and selective laser trabeculoplasty on the aqueous humor dynamics in patients with glaucoma” is the result of two prospective studies. The first study compared the baseline aqueous humor dynamics between 32 white-Caucasian and 37 African descent subjects with treatment-naïve ocular hypertension (OHT) or primary open angle glaucoma (POAG). Intraocular pressure (IOP) was measured using a pneumatonometer; morning aqueous humor flow rate was measured by fluorophotometry and trabecular outflow facility by electronic Schiøtz tonography. Uveoscleral outflow was calculated using Goldmann's equation with assumed episcleral venous pressure of 8, 9, 10, and 11 mmHg. Differences among groups were analyzed with parametric and nonparametric tests and the relationship between aqueous dynamics parameters were evaluated with linear regression analyses. No differences in aqueous humor dynamics between black African and white Caucasian patients were found. However, black patients were found to have significantly thinner corneas that could have been masking potential differences in outflow facility and IOP measurements between the racial groups. A group of these patients were treated with selective laser trabeculoplasty (SLT) to reduce their IOP. The second study investigated the effect of SLT on the aqueous humor dynamics in 18 eyes. A 21% reduction in IOP with a 55% increase in trabecular outflow facility was observed 3 months after laser treatment. No differences in aqueous humor production were found. Thus, our results showed that SLT reduces the IOP by increasing the trabecular outflow facility.