Relationship of Geographic Altitude with Foveal Avascular Zone Metrics and Vascular Density Values Assessed by OCT Angiography.

Purpose: To evaluate variations in vascular density (VD) and foveal avascular zone (FAZ) metrics in relation to geographic altitude in healthy subjects from 6 Latin American cities.

Design: Cross-sectional study.

Participants: Healthy volunteers from 6 Latin American cities.

Evaluation of VEGF gene polymorphisms and proliferative diabetic retinopathy in Mexican population.

Aim: To assess if the included vascular endothelial growth factor (VEGF) polymorphisms rs3025035, rs3025021 and rs2010963 are associated to proliferative retinopathy in a Mexican population with type 2 diabetes mellitus (T2DM).

Methods: A case-control study was conducted in adult individuals with T2DM associated to proliferative retinopathy or non-proliferative retinopathy from Oct. 2014 to Jun.

[Analysis of the resonant frequency of the middle ear in otosclerosis].

Multifrequency tympanometry scans pressures and frequencies from 226 to 2000 Hz to analyze the resonant frequency of the middle ear, which determines the balance between stiffness and mass. We studied 143 patients (a total of 200 ears) diagnosed as otosclerosis at the E.N.

[Parameters of normality in multifrequency tympanometry].

Multifrequency tympanometry studies consist of tympanography using probe tone frequencies ranging from 200 to 2000 Hz, improving the study of acoustic transmission through the tympano-ossicular system because then two components of admittance, conductance and susceptance, can be separated. The resonance frequency is the frequency at which mass and spring elements of the middle ear cancel each other out, leaving only the friction component. This measurement has been found to be more sensitive to the presence of pathologies that affect the tympano-ossicular system, such as otosclerosis and rheumatoid arthritis.