All patients will be subjected to the following:~Clinical evaluation:~History taking including name, sex and age at diagnosis of ROP.~Detailed obstetric history [maternal age, type of conception (natural, hormonal or in vitro fertilization), type of delivery (vaginal or cesarean section), single or multiple gestation, pregnancy complications (hypertension, diabetes mellitus, placental abruption, premature rupture of membranes, chorioamnionitis), drug history including steroid treatment received prior to delivery].~Neonatal data [Gestational age by weeks calculated from the last menstrual period and confirmed by physical examination, birth weight in grams, Apgar scores at 1 and 5 minutes, weight appropriate or small for gestational age, presence of hypoxia during or after delivery, need for oxygen therapy (mode of delivery, duration, oxygen saturation), presence of clinical sepsis, Respiratory distress syndrome, anemia or the need of blood transfusion].~Complete physical examination will be done to all babies including cardiac, chest, abdominal and neurological examination.~Laboratory assessment:~A- Routine assessment:~Complete blood count (CBC) for the mother.~CBC for all infants.~B- Immunological assessment: level of Interleukin-6 and 8, and Tumor necrosis factor-α will be assessed:~Umbilical cord blood will be sampled by venipuncture of umbilical vein at birth under complete aseptic conditions for determination of cytokine level. Cord blood samples will be collected on serum separator tube with gel and then are allowed to clot for 30 minutes at room temperature before centrifugation for 15 minutes at 1000xg. Serum will be removed and stored at ≤ -20 ˚c.till assessment by Lab-scan 3D using Luminex assay multiplex kits~3- Fundus examination After training on fundus examination at ophthalmology department, I will do it for babies. Current guidelines by the American Academy of Ophthalmology and Pediatrics, and American Association for Pediatric Ophthalmology and Strabismus recommend that all infants with gestational age ≤32 weeks or birth weight ≤1500g should be screened for retinopathy of prematurity (ROP). Unnecessary examinations may increase the medical costs for ROP screening. First examination will be done at age of 4 to 6 weeks of age, then every 2-3 weeks until their vessels have grown out to the ora serrate and the retina is considered mature. If ROP is diagnosed, examination will be done every 1-2 weeks according to the severity of the disease. The stage of ROP is the highest stage during all fundus examinations done.
Cord blood will be taken after birth for evaluation of cytokines level. At age of 4-6 weeks, we will do fundus examination for babies . Retrograde, we will study the perinatal risk factors in subjects found to have retinopathy. Follow up fundus will be done according to results of the first examination. By this study,we will be able later on to predict whom of preterm infants are more prone to develop retinopathy of prematurity.