الفهرس 
Effect of variation in the production factorsOnly 14 pages are availabe for public view
 |  | from | 110 |  |  |
| | | from | 110 | | |
Abstract
Autologous blood components are reported to be used in ophthalmic practice. These include; autologous serum, autologous plasma either in the form of platelet rich plasma or platelet poor plasma; and autologous plasmin.
Each one of these blood components has its own method of preparation and storage in order to meet its optimum criteria.
Autologous serum helps corneal epithelial cell proliferation, migration, and adhesion. In addition, it aids in regeneration of sensory nerves and modulates the balance between sensory and sympathetic innervations to the cornea. Thus, it is very useful in the treatment of ocular surface diseases especially dry eye disease, neurotrophic keratitis, superior limbic keratoconjunctivitis, recurrent corneal erosion syndrome and persistant epithelial defects. In addition, it has been used as a culture medium for ocular surface equivalents giving similar results to fetal bovine serum but without its bovine elements.
Platelet rich plasma is also used in the treatment of ocular surface diseases. It is found to be superior to serum in the stimulation of cellular proliferation. On the other hand, its effect on cellular migration and differantion is inferior to serum. This discripency in action together with its being more difficult to prepare than autologous serum, may explain why autologous serum is much more popular. However, platelet rich plasma has a good proliferative influence on retinal pigment epithelial cells and glial tissue. Also it helps their differentiation. Thus it has a value in the treatment of retinal breaks not suitable for laser photocoagulation, in other words macular hole.
Platelet poor plasma has haemostatic, healing, and adhesive properties. It acts as a biological and biodegradable tissue adhesive. It can be used to seal perforated corneal ulcers aiding the healing process together with allowing good wound resistance and finally autodegradation when healing is complete without causing ocular irritation. By the same mechanism, it can act as a tissue adhesive replasing sutures in sealing of clear corneal, corneoscleral and conjunctivoscleral wounds. Reported surgical uses include pterigium excision with conjunctival autografting, lamellar keratoplasty, and cataract surgery. In addition, its adhesive character makes it act as a scaffold for cultivated ocular surface equivalents. Sheets grown on matrices of platelet poor plasma have both good elasticity and transparency.
Autologous plasmin being a broad-spectrum protease is used in pharmacological vitreolysis. When injected intravitreally, it causes both vitreous liquefaction and posterior vitreous detachment. Thus it is safe, acting without causing traction on the retina. It can be used alone to induce smooth posterior vitreous detachment eg. diabetic macular edema, vitreomaular traction syndrome and vitreofoveal traction. When combined with vitrectomy, it makes the surgery easier and faster. This is of extreme value in complicated cases of vitreoretinopathies eg. traumatic macular holes, proliferative diabetic retinopathy and theoretically in retinopathy of prematurity.
Unfortunately, there is not enough data in the literature regarding the complications that may result from the use of these autologous blood components in the ophthalmic practice. Literatures reported the risk of contamination to be related to poor handling during preparation and use.