Amsler Grid– The Amsler Grid is a square-shaped grid used to detect or monitor metamorphopsia or scotoma involving the central visual field in various disorders of the macula and optic nerve head. There are 7 charts of the Amsler Grid each with a dimension of 10 cm × 10 cm. Amsler grid is basically a chart …
Amsler Grid – Types, Procedure of Testing and Clinical Indications Read More »
Papillae : Flat-topped elevations in the tarsal conjuctiva containig blood vessels and having a smooth, velvety appearance, present in some forms of allergic conjuctivitis. Papillae are flat-topped polygonal elevations in the conjunctiva that are separated from eachother by a narrow gap . A papilla consists of a tuft of vessels covered by epithelium and surroundedby …
Follicle: localised area of lymphoid herplasia, appearing white or grey elevations in the upper or lower tarsal conjunctiva, which may be accompned by inflammation(folliculosis) accompanrd by viral, allergic or bacterial conjuctivitis. Follicle formation in conjunctiva is a lymphoidreaction to insult of the conjunctiva, eg, bacterial, viral, irritant and drugs. Follicles are small hemisphericalraised spots; there …
Conjunctival Follicles – Definition, Histopathology and Causes Read More »
Average measurements of adult lens Thickness = 4-5 mm Diameter = 10 mm Radius of curvature of the anterior surface = 10 mm Radius of curvature of the posterior surface = 6 mm Dioptric power = 17 D Refractive index for Cortex = 1.386 & Nucleus = 1.406 STRUCTURE OF LENS The lens is a …
The lens is unique in that it has a very low water content (65%) and an extraordinarily high protein content (33%) — essential for the optimal optical function of the lens. The remaining solids, including lipids, inorganic ions, organic phosphate, nucleic acids, and various metabolites, comprise only about 2% of the total lens solids. PROTEINS …
Lens Embryology is an important topic, frequently asked in medical school exams. This article will throw light (pun unintended) on the embryology and development of lens. The rudimentary lens is first seen as a thickening of the surface ectoderm, the lens placode at 22 days gestation; it overlies the optic vesicle, an outgrowth of the …
