Background: Alopecia areata is a patchy hair loss that may occur in any hair bearing area on the body. There are many reports of ocular abnormalities such as lens and retinal changes in alopecia areata. Objective: To evaluate ocular alterations in alopecia areata with regard to the lens and retina. Patients & Methods: Seventy three patients with alopecia areata including 34 males and 39 f...

previous evidence has shown that the number of l and m cones in retina varies significantly between subjects. however, it is not clear how the variation of l/m ratio changes the behavioral performance of the subject. a model of transformation of data from retina to visual cortex for evaluation of various l/m cones ratios is presented. while l/m cone ratios close to 1 brings the best performance...

We study scaling relations of compressible strongly magnetized turbulence. We find a good correspondence of our results with the Fleck (1996) model of compressible hydrodynamic turbulence. In particular, we find that the density-weighted velocity, i.e. u ≡ ρv, proposed in Kritsuk et al. (2007) obeys the Kolmogorov scaling, i.e. Eu(k) ∼ k −5/3 for the high Mach number turbulence. Similarly, we f...

Vitreoretinal surgery is challenging even for expert surgeons owing to the delicate target tissues and diminutive workspace in retina. In addition improved dexterity accuracy, robot assistance allows (partial) task automation. this work, we propose a strategy automate motion of light guide with respect surgical instrument. This automation instrument's shadow always be inside microscopic view, w...

OBJECTIVE To demonstrate that Stargardt disease (STGD) can present with peripapillary atrophy. METHODS Retrospective case series. The medical records of 150 consecutive patients (300 eyes) were reviewed retrospectively from a STGD database from January 1999 to May 2007 at Columbia University's Harkness Eye Institute. STGD patients demonstrating peripapillary atrophy were identified. RESULTS...