Patients with acute avascular lesions of the conjunctiva and sclera will be included in the study. Patients will undergo a complete eye examination including a slit lamp, intraocular pressure measurement, and fundoscopy with dilated pupil. At the same time, laboratory examination including measurement of fasting blood sugar (FBS) level, complete blood count (CBC) and systemic blood pressure will be performed. Patients will be randomly divided into three groups. The groups will receive sham drops (normal saline), erythropoietin 3000 units in normal saline, and erythropoietin 6000 units in normal saline every 6 hours respectively. Meanwhile, all patients will receive the usual treatments based on the cause of scleral necrosis.

Eye examinations will be done daily in the first week, every other day in the second week, and then twice a week until the complete recovery of avascular lesions. In each examination, with fluorescein staining, the size of the conjunctival epithelial defect will be determined. Also, the dimensions of the avascular area of the sclera will be determined. Other examinations include measurement of visual acuity and intraocular pressure, and the patient will be evaluated in terms of iris and retinal neovascularization. The photoslit lamp will be done before starting the study and then every week.

Complete healing of the lesion is defined by complete vascularization and epithelization of the ischemia site. After the complete recovery of conjunctival and scleral necrosis, the erythropoietin drop will be stopped and the examinations including blood pressure measurement, CBC, diff and FBS will be repeated.

Inclusion Criteria:

• patients with acute conjunctival and scleral avascular lesions resulting from ocular surgery (such as pterygium resection, glaucoma, strabismus, vitreous and retinal surgery), chemical and thermal burns, and collagen-vascular disease.

Exclusion Criteria:

• a history of ocular surface tumors
• a history of tumors in any part of the body
• iris and retinal neovascularization for any reason
• proliferative diabetic retinopathy
• and systemic hypertension
• if the sclera is severely thinned and the risk of perforation of the globe is imminent, the patient is excluded from the study.