الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Corneal ulcer is one of the most dangerous eye diseases in animals which can directly lead to loss of vision. It is characterized by superficial or deep erosive processes in the cornea, with loss of epithelium and stromal exposure.
The causative agents may be trauma, eyelid defects, foreign bodies, and microbial infections.
The corneal ulcer resulting from an alkali-burn is an epithelial defect, with loss of stroma, stromal inflammation, or a combination. Alkali substances are lipophilic agents that penetrate the cornea more rapidly, thus they are even more harmful than acids and more similar to the dormant ulcers.
Despite many clinical treatments being advocated, moderate and severe alkali burns remain difficult to treat and frequently requires a prolonged treatment course with various sight-threatening complications.
In these cases, a conventional treatment for corneal epithelial defect depends on some optional strategies that includes artificial tear drops, antibiotics, non-steroidal and steroidal anti-inflammatory treatments, therapeutic contact lenses, amniotic membrane transplantation and tarsorrhaphy, sometimes these strategies may fail to control and manage this problem and need to
add some substances or chemical materials that enhance and stimulate the epithelial proliferation and differentiation.
Platelets are great suppliers of growth factors and are known for their ability to heal epithelial and internal wounds. Platelets adhere to the damaged endothelium and start a healing reaction that includes the release of numerous cytokines and growth factors.
Platelet-rich plasma (PRP) has become a common treatment in the field of ophthalmological surgery.
The present study was done to evaluate the effect of platelet rich plasma on the corneal ulcer induced by alkali burn in rabbits. This study was done at the department of surgery, faculty of veterinary medicine, New Valley University on 30 adult male New Zealand albino rabbits, with an average weight 2 kg (±200 gm) classified into four groups.
PRP was prepared by intra-cardiac blood sample (8.5ml) was aspirated from the rabbits on (1.5 ml) acid citrate dextrose anticoagulant under general anesthesia. The whole blood was centrifuged at 3000 rpm for 15 minutes to sediment down red blood cells (RBCs). The supernatant plasma was aspirated and centrifuged for another round at 4000 rpm for 20 minutes to pellet down the platelets (PRP).
Corneal ulcer was induced in all groups by using a sterile swab soaked in 1% NaOH on the central cornea for 1 min. Control group left untreated (placebo). group I (PRP topical drops) received one DROP of (autologous PRP) twice daily within 12-h intervals for 7 successive days. group II (PRP subconjunctival treated) received a single dose subconjunctival autologous PRP. A 0.5 ml autologous PRP was injected into the superior bulbar conjunctiva using a 1ml insulin syringe and 27-gauge half-inch needle. group III (Gatifloxacin topical treated) received one DROP of Gatifloxacin 0.5% twice daily with 12 hours intervals for 7 days.
The results revealed a high significant increase of platelets count in PRP samples average (1158.333×103) in comparision with whole blood samples average (392.667 ×103).
Histopathological results demonstrated that treated groups (PRP drops & subconjunctival injection) show remodeling and regeneration of induced corneal ulcer at a rate higher than (antibiotic treated group) compared with control group.
Besides, group treated with one shot of subconjunctival injection showed a very high rate of corneal epithelial healing near its normal structure compared with group treated with PRP drops.
Finally, it can be concluded that, the subconjunctival application of autologous platelet-rich plasma on corneal alkali burn ulcer is a simple and an economic treatment for ocular surface burns, free of undesirable side effects. It is a safe and easily producible material containing several mediators such as growth factors, which are needed in wound healing. PRP seems to be a good agent for clinical use in the epithelial wound healing process.