(ALK) excision of the outer layers of the cornea using an automated *keratome. It is usually used as part of a surgical procedure, to alter the shape of the cornea to correct errors of refraction.
n. an operation in which a part of the cornea is removed, usually a superficial layer. This procedure is now frequently done by an *excimer laser, either to correct refractive errors (myopia, hypermetropia), by reshaping the surface of the cornea (photorefractive keratectomy; PRK), or to remove diseased corneal tissue (phototherapeutic keratectomy). See also automated lamellar keratectomy.... keratectomy
mature *bone, in which the collagen fibres are arranged parallel to each other to form multiple layers (*lamellae) with the osteocytes lying between the lamellae. It exists in two structurally different forms: cortical (compact) and cancellous (spongy) bone. See also woven bone.... lamellar bone
Health Encyclopedia