An intrinsic fiber optic sensor is developed by inserting a section of nocore fiber between two multimode fibers and is applied for refractive index sensing. The sensing principle is based on modulation of evanescent waves, and hence intensity of transmitted light. The sensitivity of the sensor is found to increase by coating the sensing region with a thin layer of high index ZnO. The number of ZnO layers is also optimized and a high sensitivity of 804.57%/RIU is obtained for nine layers of ZnOcoated sensor, with a fast response time of 5 s. Apart from high sensitivity and a fast response time, the experimental investigations also indicate that the proposed sensor produces fairly accurate, stable and repeatable results, with negligible cross sensitivity to environmental temperature.

Total 100 patients of diagnosed age related cataracts were enrolled in the present study. Diagnostic B-Scan Ultrasonography was performed in these patients preoperatively. Detailed history was taken and examination with Slit Lamp and Tonometry were done. A. Scan Biometry was performed in all the cases. Informed consent was taken. B-Scan ultrasonography using a standard USG machine (Sonomed B5500) equipped with a real-time high-frequency probe with the contact method was done. B-scan is a good diagnostic modality for preoperative evaluation of posterior segment pathologies in the presence of cataract. B-Scan ultrasonography should be performed routinely in pre-operative assessment of cataract patients to diagnose pathologies of posterior segment that may influence the surgical strategy and visual prognosis of patients after cataract surgery. Diagnosing and characterizing the abnormalities with great accuracy by B-scan not only helps in preoperative cases but also changes the management of various other patients.

BACKGROUND Slowly progressive auto-degenerative neuropathy and changes of the optic nerve are well known in Open angle glaucoma. Glycaemic conditions in the body importantly may effect these damages, mutually or independent of the associated ocular pathology. An objective parameter if established for determining the correlation of the both would assist to set up proper ways of diagnosis and management of patients with Diabetics with POAG. The aim of this study is to evaluate the optic nerve head (ONH) parameters of primary open-angle glaucoma (POAG) patients with and without diabetes and to investigate the effect of the metabolic control of diabetes on ONH topography. MATERIALS AND METHODS A study group of 61 eyes of 61 POAG patients with type 2 diabetes mellitus and a control group of 61 eyes of 61 POAG patients without diabetes were recruited for the study. Complete ophthalmic examinations of all patients were performed and the quantitative optic disc parameters were evaluated with HbA1c measurements of diabetic patients. RESULTS Mean RNFL thickness of the study group was statistically lower than the control group (P<0.001). The difference in other parameters of the OCT between the groups were insignificant. In the study group, the duration of the diabetes and HbA1c were not significantly correlated to any of the OCT parameters of ONH. CONCLUSION The duration of diabetes and HbA1c levels in diabetic population do not seem to show any significant correlation with the optic nerve head parameters and retinal nerve fibre thickness as measured with optical coherence tomography. However, larger and controlled studies are warranted to confirm these findings.

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