Cone-Photoreceptor Density in Adolescents With Type 1 Diabetes.

Purpose: Changes to retinal structure and function occur in individuals with diabetes before the onset of diabetic retinopathy. It is still unclear if these changes initially affect vascular or neural retina, or if particular retinal areas are more susceptible than others. This paper examines the distribution of cone photoreceptor density in the retina of adolescents with type 1 diabetes.

Phenotypic characteristics including in vivo cone photoreceptor mosaic in KCNV2-related "cone dystrophy with supernormal rod electroretinogram".

Purpose: To report phenotypic characteristics including macular cone photoreceptor morphology in KCNV2-related "cone dystrophy with supernormal rod electroretinogram" (CDSR).

Methods: Seven patients, aged 9 to 18 years at last visit, with characteristic full-field electroretinographic (ERG) features of CDSR were screened for mutations in the KCNV2 gene. All patients underwent detailed ophthalmological evaluation, which included distance and color vision testing, contrast sensitivity measurement, fundus photography, fundus autofluorescence (FAF) imaging, and spectral domain-optical coherence tomography (SD-OCT).

Diurnal rhythms of spherical refractive error, optical axial length, and power in the chick.

Purpose: To measure the diurnal variation of spherical equivalent refractive error (mean ocular refraction or MOR) and to investigate factors contributing to it in chick, an important animal myopia model.

Methods: Nine chicks developed naturally on a 14-hour light/10-hour dark cycle. Optical axial length (OAL) and Hartmann-Shack wavefront error (HSWE) measurements, including pupil size, were taken starting on day 7, at eight times during the following 32 hours.

Longitudinal in vivo imaging of cones in the alert chicken.

Purpose: To demonstrate the feasibility of in vivo measurements of cones and their distributions as a function of normal growth without adaptive optics (AO) and also discuss the potential advantages and disadvantages of AO imaging in the chick, an animal model of myopia.

Methods: Chicks were obtained on the day of hatching. Axial length and retinoscopy measurements were performed on days 0 and 14.

Blur on the retina due to higher-order aberrations: comparison of eye growth models to experimental data.

In the simplest model of eye growth, the ocular optics uniformly scale upwards, as do monochromatic higher-order aberrations (HOA) and linear blur on the retina. However, measured HOA remain constant or decrease with growth in some species. A new model, which holds HOA and the associated linear blur on the retina constant, was used to predict changes in HOA and resulting image quality on the retina during growth, in each of chick, monkey, and human.

Depolarization properties of the optic nerve head: the effect of age.

The degree of polarization (DOP) of the light reflected from the optic nerve head has been assessed by means of a polarimetric scanning laser ophthalmoscope as a function of the age of the participants. Four fundus images corresponding to independent polarization states in the recording pathway were used to compute the spatially-resolved DOP. This was not uniform across the optic nerve head and depended on both the location and the participant's age.

Improved scanning laser fundus imaging using polarimetry.

We present a polarimetric technique to improve fundus images that notably simplifies and extends a previous procedure [Opt. Lett.27, 830 (2002)].

Characterizing image quality in a scanning laser ophthalmoscope with differing pinholes and induced scattered light.

We quantify the effects on scanning laser ophthalmoscope image quality of controlled amounts of scattered light, confocal pinhole diameter, and age. Optical volumes through the optic nerve head were recorded for a range of pinhole sizes in 12 subjects (19-64 years). The usefulness of various overall metrics in quantifying the changes in fundus image quality is assessed.

Aberrations of chick eyes during normal growth and lens induction of myopia.

Understanding the control of eye growth may lead to the prevention of nearsightedness (myopia). Chicks develop refractive errors in response to defocusing lenses by changing the rate of eye elongation. Changes in optical image quality and the optical signal in lens compensation are not understood.