Cone-shaped cornea Cone-shaped cornea can be a stand-alone condition or a component of many syndromes. It is characterized by a central, forward protrusion of the cornea in a conical shape, often resulting in highly irregular myopic astigmatism and varying degrees of visual impairment without inflammation. (Etiology) The cause is unknown. Because it is sometimes associated with other abnormalities of the body or eye, some believe it may be a genetic developmental abnormality, others believe it is a nutritional degeneration, or both may interact with each other. It has been suggested that it may be related to abnormal levels of trace elements in the body. Endocrine disorders (hypothyroidism) and allergic diseases (spring conjunctival keratitis) have also been reported to be associated with this disease. (Clinical manifestations) The disease occurs in young people aged 15-20 years, with an average age of 13,5 years for vision loss and 21 years for corneal transplantation. It is more common in males, with 70% of both eyes. (clinical stage) A latent stage cone cornea is not obvious, generally one eye is diagnosed with cone cornea, the other eye refractive error, then consider the possibility of the disease. The initial stage is dominated by refractive error, starting with myopia and progressing to astigmatism or irregular astigmatism, with possible correction of vision in the general eye and distortion of the concentric rings and axes of the corneal image with the application of Placido disc examination. In the completed stage, typical cone corneal symptoms appear, vision further decreases, general glasses are no longer helpful, only hard contact lenses can be used to correct vision, clinically four major signs: 1, Munson’s sign: when the affected eye looks down, the corneal deformity is clearly shown by the curvature of the lid margin. 2, Fleischer ring: iron deposits in the corneal epithelium, mainly gathered in the basal cells, the brown ring formed by the tear film impregnated cone bottom, dilation after the pupil blue light striking. 3, Vogt’s line: appears in the posterior part of the basal lamina, a vertical pressure line caused by an increase in the folds of the stromal plate layer. It disappears when pressure is applied to the eye. 4.Acute edema: It is caused by acute rupture of the posterior elastic lamina and acute edema of the stroma and epithelium caused by atrial water entering the cornea. In severe cases, the anterior elastic membrane ruptures and is replaced by a fibrous tissue scar. If the scar is not on the visual axis, visual acuity improves; if it is on the visual axis, visual acuity decreases. Degenerative stage The corneal subepithelium appears degenerative, with vitreous degeneration predominating. A linear or reticular scar is formed in the center of the cornea, and vision is sharply reduced. There is neovascular growth in the superficial layer of the cornea. Treatment Medication, optical correction and surgery. 1, Trigonelline and night application of compression bandage. 2.Corneal contact lens. 3.Corneal transplantation surgery.