Genotyping microarray for CSNB-associated genes.

Purpose: Congenital stationary night blindness (CSNB) is a clinically and genetically heterogeneous retinal disease. Although electroretinographic (ERG) measurements can discriminate clinical subgroups, the identification of the underlying genetic defects has been complicated for CSNB because of genetic heterogeneity, the uncertainty about the mode of inheritance, and time-consuming and costly mutation scanning and direct sequencing approaches.

Methods: To overcome these challenges and to generate a time- and cost-efficient mutation screening tool, the authors developed a CSNB genotyping microarray with arrayed primer extension (APEX) technology.

A new method to monitor visual field defects caused by photoreceptor degeneration by quantitative optical coherence tomography.

Purpose: To correlate the dimension of the visual field (VF) tested by Goldman kinetic perimetry with the extent of visibility of the highly reflective layer between inner and outer segments of photoreceptors (IOS) seen in optical coherence tomography (OCT) images in patients with retinitis pigmentosa (RP).

Methods: In a retrospectively designed cross-sectional study, 18 eyes of 18 patients with RP were examined with OCT and Goldmann perimetry using test target I4e and compared with 18 eyes of 18 control subjects. A-scans of raw scan data of Stratus OCT images (Carl Zeiss Meditec, AG, Oberkochen, Germany) were quantitatively analyzed for the presence of the signal generated by the highly reflective layer between the IOS in OCT images.

Impact of optic media opacities and image compression on quantitative analysis of optical coherence tomography.

Purpose: To analyze the impact of opacities in the optical pathway and image compression of 32-bit raw data to 8-bit jpg images on quantified optical coherence tomography (OCT) image analysis.

Methods: In 18 eyes of nine healthy subjects, OCT images were acquired from the central macula. To simulate opacities in the optical system, neutral-density (ND) filters with linear absorption spectra were placed between the OCT device and examined eyes.

Is pseudophakia a risk factor for neovascular age-related macular degeneration?

Purpose: To examine the possible association between pseudophakia and neovascular age-related macular degeneration (AMD).

Methods: Reports of all patients undergoing fluorescein angiography in the authors' department over a 6-year period were retrospectively reviewed. Four hundred ninety-nine patients with recent onset of neovascular AMD in one eye and early age-related maculopathy (ARM) in the fellow eye were included in the study.

Development of a genotyping microarray for Usher syndrome.

Background: Usher syndrome, a combination of retinitis pigmentosa (RP) and sensorineural hearing loss with or without vestibular dysfunction, displays a high degree of clinical and genetic heterogeneity. Three clinical subtypes can be distinguished, based on the age of onset and severity of the hearing impairment, and the presence or absence of vestibular abnormalities. Thus far, eight genes have been implicated in the syndrome, together comprising 347 protein-coding exons.

Different amino acid substitutions at the same position in rhodopsin lead to distinct phenotypes.

Purpose: Identification of a novel rhodopsin mutation in a family with retinitis pigmentosa and comparison of the clinical phenotype to a known mutation at the same amino acid position.

Methods: Screening for mutations in rhodopsin was performed in 78 patients with retinitis pigmentosa. All exons and flanking intronic regions were amplified by PCR, sequenced, and compared to the reference sequence derived from the National Center for Biotechnology Information (NCBI, Bethesda, MD) database.

Quantitative analysis of OCT characteristics in patients with achromatopsia and blue-cone monochromatism.

Purpose: To quantify optical coherence tomography (OCT) images of the central retina in patients with blue-cone monochromatism (BCM) and achromatopsia (ACH) compared with healthy control individuals.

Methods: The study included 15 patients with ACH, 6 with BCM, and 20 control subjects. Diagnosis of BCM and ACH was established by visual acuity testing, morphologic examination, color vision testing, and Ganzfeld ERG recording.

Differential P1-purinergic modulation of human Schlemm's canal inner-wall cells.

Intraocular pressure is directly dependent on aqueous humor flow into, and resistance to flow out of, the eye. Adenosine has complex effects on intraocular pressure. Stimulation of A1 and A2A adenosine receptors changes intraocular pressure oppositely, likely through opposing actions on the outflow of aqueous humor.

Human trabecular meshwork cell volume regulation.

The volume of certain subpopulations of trabecular meshwork (TM) cells may modify outflow resistance of aqueous humor, thereby altering intraocular pressure. This study examines the contribution that Na+/H+, Cl-/HCO exchange, and K+-Cl- efflux mechanisms have on the volume of TM cells. Volume, Cl- currents, and intracellular Ca2+ activity of cultured human TM cells were studied with calcein fluorescence, whole cell patch clamping, and fura 2 fluorescence, respectively.

The Pulfrich phenomenon in a large population of young healthy subjects.

Background: To determine whether the Pulfrich phenomenon, an optical illusion occurring in many ophthalmological diseases, is perceived equally in both eyes in a large group of healthy medical students.

Subjects And Methods: A pendulum bob swinging perpendicular to the direction of observation was observed with either the right or the left eye covered with neutral density filters (50, 80 or 90 % absorption) and the apparent elliptical pendulum movement measured in depth. Interocular time delay was calculated from depth.