Evaluate the effect of corneal thickness, densitometry and curvature on intraocular pressure (IOP) measurements obtained by Goldmann applanation tonometry (GAT), non-contact tonometry (NCT), rebound tonometry (RT), and dynamic contour tonometry (DCT). A cross-sectional prospective study involving 40 participants was performed. Corneal measurements were obtained using Pentacam (Oculus GMbH, Wetzlar, Germany), densitometry was measured at annuli of 0–2, 2–6, 6–10 and 10–12 mm. The relationship between corneal thickness (central, 4 and 6 mm), corneal astigmatism and corneal densitometry and IOP was examined. There was a significant relationship between corneal thickness (central, 4 and 6 mm) and GAT180, GAT90, RT, and NCT (P < 0.001 for all comparisons) but not for DCT. Higher corneal densitometry (6–10 mm and 10–12 mm zones) was associated with higher IOP from GAT180 and GAT90, and higher densitometry in the 6–10 mm zone correlated with higher IOP from NCT, however corneal densitometry increased with age. Accounting for age, the relationship between corneal densitometry and IOP measurements was not significant. In eyes with greater corneal astigmatism there was a greater difference between GAT90 and GAT180 measurements. IOP measurements may be affected by corneal thickness, densitometry and curvature. DCT was less affected by properties of the cornea compared to other devices.

Objetivo: Verificar o efeito da instilação correta de colírios hipotensores oculares no comportamento pressórico de pacientes portadores de glaucoma crônico. Métodos: Estudo prospectivo realizado em 90 olhos, de 47 pacientes. Em cada participante era realizada uma minicurva pressórica antes, e outra após lhe ser explicado como proceder à instilação correta de colírios. A seguir, as médias pressóricas obtidas nas duas minicurvas eram comparadas. Resultados: Houve queda significativa de 22,3% na pressão intra-ocular média de 35 (38,9%) olhos. Dos restantes, 35 (38,9 %) olhos exibiram pequena queda (-8,2%) em sua média pressórica e, 20 (22,2 %), pequeno aumento (+8,4%), ambos não estatisticamente significantes. Conclusões: Verificou-se que parcela expressiva da população estudada conseguiu obter redução adicional em sua média pressórica por meio da instilação correta de colírios. Portanto, o ensino da técnica adequada da instilação de colírio é necessária a todos os pacientes, podendo resultar em benefício extra para os usuários de medicação hipotensora ocular. Effect of correct eyedrop instillation on the intraocular pressure of glaucoma patients