Longitudinal imaging of microvascular remodelling in proliferative diabetic retinopathy using adaptive optics scanning light ophthalmoscopy.

Purpose: To characterise longitudinal changes in the retinal microvasculature of type 2 diabetes mellitus (T2DM) as exemplified in a patient with proliferative diabetic retinopathy (PDR) using an adaptive optics scanning light ophthalmoscope (AOSLO).

Methods: A 35-year-old T2DM patient with PDR treated with scatter pan-retinal photocoagulation at the inferior retina 1 day prior to initial AOSLO imaging along with a 24-year-old healthy control were imaged in this study. AOSLO vascular structural and perfusion maps were acquired at four visits over a 20-week period.

Local flicker stimulation evokes local retinal blood velocity changes.

We investigated the effect of localized visual stimulation on human retinal blood velocity using an adaptive optics scanning laser ophthalmoscope (AOSLO). To measure the blood velocity response, the AOSLO scanning raster was moved over the target arteries and red blood cell velocity was measured. Localized visual stimuli were delivered by projecting flicker patterns inside or outside the target artery's downstream region.

Variation of cone photoreceptor packing density with retinal eccentricity and age.

Purpose: To study the variation of cone photoreceptor packing density across the retina in healthy subjects of different ages.

Methods: High-resolution adaptive optics scanning laser ophthalmoscope (AOSLO) systems were used to systematically image the retinas of two groups of subjects of different ages. Ten younger subjects (age range, 22-35 years) and 10 older subjects (age range, 50-65 years) were tested.

Noninvasive measurements and analysis of blood velocity profiles in human retinal vessels.

Purpose: To quantitatively model the changes in blood velocity profiles for different cardiac phases in human retinal vessels.

Methods: An adaptive optics scanning laser ophthalmoscope (AOSLO) was used to measure blood velocity profiles in three healthy subjects. Blood velocity was measured by tracking erythrocytes moving across a scanning line.

Individual variations in human cone photoreceptor packing density: variations with refractive error.

Purpose: To measure the variation in human cone photoreceptor packing density across the retina, both within an individual and between individuals with different refractive errors.

Methods: A high-resolution adaptive optics scanning laser ophthalmoscope was used to image the cones of 11 human eyes. Five subjects with emmetropia and six subjects with myopia were tested (+0.