Periocular Region

About: Periocular Region is a research topic. Over the lifetime, 256 publications have been published within this topic receiving 4424 citations.

Semaphorin3A Regulates Neural Crest Migration Into the Eye During Cornea Development

Abstract: Purpose: To determine the role of lens-derived Semaphorin3A during neural crest migration into the eye. Methods: Using in situ hybridization, we characterized the expression of Semaphorin3A (Sema3A) in the eye and its receptor Neuropilin-1 (Npn-1) by neural crest cells in the periocular region during cornea development in chick embryos. Migration of neural crest cells into the eye was tracked after lens ablation or inhibition of Sema3A in the lens using quail-chick chimera technique and immunohistochemistry. Results: We show that the lens continuously expresses Sema3A during cornea development and neural crest cells express Npn-1 in the periocular region. Interestingly, only the neural crest cells that down regulate Npn-1 migrate into the eye to form the cornea. We also show that the lens, which immediately underlies the ectoderm, inhibits neural crest migration into the rudimentary eye since lensectomy results in premature migration and malformation of the cornea. Additionally, inhibiting of Sema3A signaling in the lens phenocopies lensectomy. Conclusions: Our results demonstrate that lens-derived Sema3A regulates periocular neural crest migration into the eye and is necessary for the proper formation of the cornea.

Eyelid basal cell carcinoma with neuroendocrine differentiation: a case report and literature review

Abstract: Basal cell carcinoma (BCC) is the most common type of malignant tumor in the periocular region. BCCs with neuroendocrine differentiation in the periocular region, however, have not been described i...

Improving Cross-Smartphone Periocular Verification in Visible Spectrum Using Time-Frequency Features of Laplacian Decomposition

Abstract: Smartphones are gaining popularity as a biometric authentication device for many applications like banking and e-commerce. While multiple smartphone manufacturers providing phones with new features, consumers venture to try new phones or use multiple devices to sign into secure applications leading to a situation, in which they have to deal with data emerging from various smartphones along with manifold capture conditions. Recognition processes involving such cross-smartphone data leads to degraded biometric performance. In this work, we propose a novel technique to extract texture features from the periocular region by decomposing the images into Laplacian pyramids of various scales and obtain frequency responses in different orientations. Further, we propose to encode the features sparsely as a means to increase the cross-smartphone authentication using periocular region. From the extensive set of experiments conducted on a publicly available smartphone periocular database, we demonstrate the improvement using the proposed feature encoding and comparison for authentication scenarios. An average gain in Equal Error Rate of around 10 % is achieved while the best gain of 16% is obtained for various comparisons as compared to previously reported verification scores. The obtained gain in performance indicates the applicability of the proposed feature extraction technique for real-life authentication scenarios employing data from different smartphones in the visible spectrum.